Vital Vitamins (Complete Vitamin Directory)

Quick Links:

Return to Table of Contents

Vitamin History

Vitamins are nutrients needed by the human body in relatively small milligram (mg) and microgram (mcg) amounts, but nonetheless are vital for health to thrive and life to exist.

The idea that vitamins existed was first realized by Scottish surgeon James Lind who in 1749 discovered that something in citrus fruits helped prevent “scurvy” (a common deadly condition of the time where the structural connective tissue substance collagen is not properly formed).  Although Dr. Lind’s experiments (which are considered the first controlled and recorded experiments in scientific history) began in 1747 while serving as the ship’s surgeon in the British Royal Navy, they were slow to be recognized and adopted.

It wasn’t until 1795 that limes (which were readily available to the British) became standard issue in the British Royal Navy (and is how the British became known as “limeys”).  Likewise, others in the 1800s and early 1900s began to realize that there was something in certain foods that supported health and life.  In 1906 English biochemist Sir Frederick G. Hopkins called these substances “accessory factors.”

From research that dated back to 1884 involving rice bran and its effect on the condition known as “beriberi” (a deficiency condition of the nervous system), the first water-soluble vitamin was discovered in 1910 by Japanese scientist Umetaro Suzuki, which was eventually named vitamin B1 (later called thiamin once its chemical composition was determined by India-born British researcher Robert R. Williams, Jr. in 1935).

From research that dated back to 1906, the first fat-soluble vitamin was discovered in 1917 independently by American researchers Elmer McCollum and Thomas Osborne, which was eventually named vitamin A.

In 1912 Polish-born U.S. biochemist Casimir Funk with Sir Frederick Hopkins first formulated the hypothesis of deficiency disease, with Casimir Funk generally credited with being the first to isolate specific vitamins.  It was Casimir Funk (known as the Father of Vitamins) who called these substances “vital amines” and first proposed these substances be named “vitamine” after the Latin word for life “vita,” with the “amine” portion added because it was thought at the time that all these substances contained nitrogen containing amino acids or amines (ammonia derivatives).  When it was realized that they all did not contain nitrogen amines, English biochemist Sir Jack C. Drummond proposed in 1920 that the “e” in amine be dropped to avoid confusion.  From that time on they have been known as vitamins.

Return to Vitamin Directory

What Are Vitamins

Vitamins are organic chemical substances that naturally occur in food, and since the early 1900s as nutritional supplements (officially classified by the FDA in 1968 as “dietary supplements”).  Vitamins are “organic” because they contain carbon and/or originate from once-living plants or animals, and basically act as catalytic coenzymes which work with the other nutrients required for body function, health and life.

Vitamins cannot be produced by the human body and therefore are classified as “essential” nutrients, thus it is essential that they be consumed regularly so the body can function and health can be maintained.

Vitamins fall into one of two basic categories; Fat-soluble (vitamins A, D, E and K) which require that they be taken with foods that contain some amount of dietary fat to facilitate their uptake, and water-soluble (all of the B-complex vitamins and vitamin C) which require water to be present for their dissolution and uptake.

Vitamins are classified by their biological and chemical activity within the body rather than their structure, and have many diverse biochemical functions.  Vitamins can function as: Hormones (vitamin D); antioxidants (vitamins C, E and beta-carotene); mediators of cell-signaling and regulators of cell and tissue growth and differentiation (vitamin A); function as a “provitamin” (precursor) for the activity of a vitamin (beta-carotene as a precursor of vitamin A activity); function as a “preformed” vitamin that the body converts to vitamin activity (vitamin A and vitamin D3); function as a transitional chemical for the activity of a vitamin (ascorbic acid that possesses vitamin C activity); function as precursors for enzyme cofactor bio-molecules (coenzymes) that help act as catalysts and substrates in cellular metabolism (B-complex vitamins); and function as energy cofactors (vitamin B1 for carbohydrate metabolism).

High dose intakes of the water-soluble vitamins (B-complex and vitamin C) require normal functioning kidneys so the excess can be excreted.  High intakes of fat-soluble vitamins can build up in tissues and cause deleterious health effects if too much are consumed.  Those with compromised kidney function, or any other health condition, should only take vitamin supplements with the guidance of their doctor.  This applies to all vitamin supplements, both fat-soluble and water-soluble vitamins.

Return to Vitamin Directory

Antioxidants & Free Radicals

Some vitamins (vitamins C, E, beta-carotene) have antioxidant abilities, which helps prevent oxidative stress and fight the potential damage done by free radicals.  The Institute of Medicine defines dietary antioxidants in their published book titled Dietary Reference Intakes as:  “A dietary antioxidant is a substance in foods that significantly decreases the adverse effects of reactive species, such as reactive oxygen and nitrogen species, on normal physiological functions in humans.”

It is believed that high levels of oxidants (highly-reactive oxygen free radical species, aka free radicals) which are produced by oxidative metabolism (oxygen used during cellular metabolism) causes oxidative stress which can cause cell dysfunction and damage to the cells, and as a result may significantly increase or contribute to the risk of chronic degenerative health conditions.  In addition to the vitamins indicated, certain minerals (zinc, selenium, copper, manganese and iron) are thought to also have specific antioxidant characteristics.  Antioxidants may well prove to be the first line of defense against chronic degenerative health conditions, and may fight cellular aging because of their ability to protect cells from free radical damage.

Free radicals are unstable atoms, molecules or ions that lack one or more electron in their structure, which makes them highly reactive.  When they come into contact with other substances within the body they steal electrons from them, which cause the substances to steal electrons themselves.  This sets off a chain reaction that breaks down normal chemical bonds in cells and tissues, interferes with the normal function of enzymes and hormones, and adversely affects DNA.  Antioxidants quell free radical activity by donating electrons, without being reactive themselves, thus stopping the free radical chain reaction.

Return to Vitamin Directory

Vitamin Measurements

Vitamin amounts are measured by weight in grams (g) (which is 1,000 milligrams), in milligrams (mg) (which is 1,000 micrograms), and in micrograms (mcg).  Some vitamins (A, D and E) are measured by their biological activity in International Units (IU).  The IU measurement is a bit more arbitrary as a form of measure than actual weight because the vitamins that use it are found in different forms, such as retinol, palmitate, and beta-carotene as forms of vitamin A, ergocalciferol (D2) and cholecalciferol (D3) as forms of vitamin D, and mixed tocopherols (alpha, beta, delta and gamma tocopherols) and tocotrienols (and mixed tocotrienols) as forms of vitamin E.

Return to Vitamin Directory

Intake References

RDA – The average daily dietary nutrient intake level designated by the Institute of Medicine sufficient to meet the nutrient requirement of most healthy adults, is known as the Recommended Dietary Allowance (RDA), and is part of the set of guidelines known as the Dietary Reference Intakes (DRIs).  RDAs are a planning tool as a guideline for amount of nutrient intake.

AI – The average daily dietary nutrient intake level designated by the Institute of Medicine as adequate for apparently healthy people when an RDA cannot be determined, is known as Adequate Intake (AI), and is part of the set of guidelines known as Dietary Reference Intakes (DRIs).  AIs are an assessment tool.

UL – The highest average daily dietary nutrient intake level designated by the Institute of Medicine that is likely to pose no risk of adverse health effects in most adults (but increases above the UL may increase potential risk of adverse effects), is known as the Tolerable Upper Intake Level (UL), and is part of the set of guidelines known as the Dietary Reference Intakes (DRIs).  ULs are an assessment tool.

RDI – The average daily dietary nutrient intake level designated by the Food and Drug Administration (FDA) for healthy adults who consume 2,000 to 2,500 calories a day, is referred to on food labels as Percent Daily Value (% DV), and is known as the Reference Daily Intake (RDI) (previously known as the US RDA).  RDIs are a planning tool as a guideline for amount of nutrient intake in relation to the total calories consumed.

ALT – The average daily dietary nutrient intake level commonly suggested for healthy adults by most nutritionally knowledgeable alternative doctors and nutritionists, with such Alternative (ALT) intake levels recognized or believed to have added health benefits.  ALTs are a planning tool as a guideline for amount of nutrient intake.

TOX – The average daily dietary nutrient intake level for adults generally regarded as Toxic (TOX) or believed to produce adverse effects, if known.  TOXs are a guideline of toxic amounts of nutrient intake.

Where an Intake Reference is not indicated, the amount is either not known or has not been established.  However, anything in very large amounts can have deleterious effects (even water, which is probably the most benign thing that is consumed, can cause death if consumed in massive amounts).  All amounts indicated are for healthy adults.  Do not start a supplement regimen without first checking with your doctor.

Return to Vitamin Directory

Vitamin A

Vitamin A (retinol)  –  Vitamin A (so named because it was the first fat-soluble vitamin discovered) is a preformed fat-soluble vitamin known as retinol from animal foods that converts in the body to vitamin A activity.  Retinyl acetate and retinyl palmitate are the more stable forms of retinol used in vitamin A dietary supplements.  The name “retinol” comes from a form of vitamin A called “retinal” that was discovered to transmit light sensations to the retina portion of the eye, and was determined to be responsible for preventing “night blindness.”  Vitamin A supports: Healthy eyes and vision, mediates cell-signaling, regulates cell and tissue growth and differentiation, bone formation, cell membranes, DNA gene transcription, healthy skin, reproductive function, and the integrity of the immune system.  Unlike the water-soluble form of vitamin A (beta-carotene), fat-soluble vitamin A (retinol) accumulates in body fat tissues and can be toxic in amounts that are significantly above the RDA. 
Deficiency:  Night blindness, dry eyes, skin problems, et al.
Food Sources:  Animal foods, such as egg yolk, butter, cream and vitamin A fortified milk, and especially liver and cod liver oil.
RDA:  3,000 IU of vitamin A per day for adult males, and 2,300 IU of vitamin A per day for adult females. 
UL:  10,000 IU of vitamin A per day for adults. 
ALT:  5,000 IU of vitamin A per day (with about half from beta-carotene). 
TOX:  5,000 IU of vitamin A per day in the elderly has been associated with weak bones.  10,000 IU of vitamin A per day in pregnant women increases the risk of birth defects.  Continued use of 25,000 IU of vitamin A per day can cause liver damage in adults.  Chronic intake of 50,000 IU of vitamin A per day is regarded as toxic in adults (20,000 IU per day is toxic in infants and young children).  Acute toxicity with dire results can occur in adults with a single dose of 2,000,000 IU or more of vitamin A (acute toxicity in infants or young children can occur with a single dose of 25,000 IU per kilogram of body weight).

Return to Vitamin Directory


Beta-carotene –  A water-soluble antioxidant provitamin that converts to vitamin A activity in the body (a provitamin is a precursor that the body transforms into vitamin activity when ingested).  Beta-carotene is perhaps the best known of a group of antioxidant phytochemicals known as carotenoids (“phyto” means plant).  Carotenoids are the brightly colored pigments (such as yellow, red and orange) that are naturally present in nature, primarily in plants but also in such things as egg yolk (as lutein).  More than 600 carotenoids have been indentified, of which about 30 of them have been determined to have provitamin A activity.  All have antioxidant properties, with lycopene (in tomatoes) believed to be the most potent.  Lycopene is unusual in that its antioxidant properties become concentrated when the food source is cooked (which significantly enhances the antioxidants and appeal of tomato paste).  Some of the better known carotenoids include: Lutein, lycopene, zeaxanthin, cryptoxanthin, and alpha-carotene.  Beta-carotene basically does everything that vitamin A does, but in addition also functions as an antioxidant (antioxidants regulate oxidative stress reactions, i.e., fight free radicals and the damage they can do to cells).  Unlike the fat-soluble form of vitamin A (retinol), beta-carotene is generally considered to be non-toxic.  Excess beta-carotene is stored in the liver until needed and may turn the skin (and liver) a yellow/orange color.  No RDA has been established for beta-carotene.  Some alternative health professionals have suggested that 10,000 IU to 25,000 IU of beta-carotene be consumed per day.  However, recent research suggests that large doses of beta-carotene in supplement form may increase the risk of serious deleterious conditions in those who drink alcohol and smoke (an increased intake of vitamin C is thought to help offset this risk).  Some nutritional supplements contain both beta-carotene and the retinol form of vitamin A, however the retinol form usually only makes up about 10-20% of the total vitamin A activity.  There have been no reports of beta-carotene concerns from food, or about the other carotenoids from food, other than the indicated skin (and liver) yellow/orange discoloration which cleared up once the excess consumption of them were discontinued. 
Deficiency:  Night blindness, dry eyes, skin problems, et al.
Food Sources:  Plant foods, such as orange colored vegetables and fruits, and especially sweet potatoes, carrots and carrot juice, pumpkin, butternut squash, spinach (hid by the green chlorophyll content), and cantaloupe. 
RDA:  None established. 
ALT:  Beta-carotene 10,000 IU to 25,000 IU per day, with much lesser amounts of other carotenoids per day such as: Lutein 2-5 mg, lycopene 2-3 mg, zeaxanthin 300 mcg to 6 mg, astaxanthin 1,000 mcg (1 mg), and alpha-carotene 1,000 mcg (1 mg). 
TOX:  Beta-carotene is considered non-toxic but high intakes may turn the skin a yellow/orange color.  High doses of beta-carotene in smokers who drink alcohol may have an increased risk of serious deleterious conditions.  Supplemental amounts of the other carotenoids greater than indicated is ill-advised.  Carotenoids naturally present in food are considered safe (and are thought to have health benefits), but excess intake of certain foods can cause a skin discoloration because of their carotenoid content, such as orange from large amounts of carrot juice and red from the consumption of large quantities of tomato juice (which tends to disappear when excess intake stops).

Return to Vitamin Directory

Vitamin B1

Note: To prevent a possible imbalance when taking the B-complex vitamins in supplement form it is generally recommended that the entire B-complex be taken in addition to whatever individual B-complex vitamin is taken.  The entire B-complex consists of vitamins B1, B2, B6, B12, niacin, pantothenic acid, folic acid and biotin.

Vitamin B1 (thiamine or thiamin)  –  A water-soluble B-complex vitamin that functions as a coenzyme that supports energy production, carbohydrate metabolism, and nerve function.  Vitamin B1 plays a critical role with magnesium and adenosine triphosphate (ATP) in the production of cellular energy from food.  Vitamin B1 is so named because it was the first water-soluble vitamin discovered, and became known as thiamine once its chemical composition was established.  Consuming large amounts of tea or coffee (including decaffeinated) has been associated with thiamine depletion.  Since 1943 small amounts of thiamine, riboflavin, niacin and iron have been added to milled flour to replace that which is lost during the milling process, with the resulting flour called “enriched flour.”  A fat-soluble form of thiamine known as “benfotiamine” has been used for a degenerative nerve condition (usually in the legs and feet) common in those with blood sugar problems.  Recent research indicates that benfotiamine may also be useful for a condition known as ”uveitis” which is a common inflammatory and painful eye condition that is one of the leading causes of blindness, and is often associated with autoimmune disorders. 
Deficiency:  Degenerative nerve damage, lack of energy, and “beriberi” (a known deficiency condition) that affects the heart, muscles, nerves and digestive system.
Food Sources:  Plant foods, especially whole grains and wheat germ.
RDA:  1.2 mg of vitamin B1 per day for adult males, and 1.1 mg of vitamin B1 per day for adult females. 
ALT:  At least 1.5 mg of vitamin B1 per day; most suggest 25-50 mg of vitamin B1 per day.  150-600 mg per day of benfotiamine has been used for degenerative nerve conditions of the legs and feet (common in those with blood sugar problems), but should only be used with the guidance of a knowledgeable doctor. 
TOX:  No known toxic or adverse effects of thiamine up to 200 mg per day.  Excess water-soluble thiamine is believed to be excreted.  Because it is fat-soluble, it may be possible to get too much benfotiamine and thus should only be used with the guidance of a knowledgeable doctor familiar with what it is being used for. 

Return to Vitamin Directory

Vitamin B2

Vitamin B2 (riboflavin)  –  A water-soluble B-complex vitamin that functions as a coenzyme that supports energy production, cellular function, vision, and antioxidant activity.  Vitamin B2 participates in the enzymatic use of glutathione, a major cellular antioxidant, via the glutathione oxidation-reduction reaction (glutathione redox cycle) – glutathione is known as the “master antioxidant.”  Vitamin B2 became known as riboflavin once its chemical composition was established.  It is riboflavin supplementation that is responsible for the harmless bright yellow color of urine. 
Deficiency:  Mouth lesions, skin and scalp problems (such as seborrhea dermatitis), and possibly cataract formation. 
Food Sources:  Widely distributed in small amounts in many foods, and is especially in milk, eggs, almonds and spinach. 
RDA:  1.3 mg of vitamin B2 per day for adult males, and 1.1 mg of vitamin B2 per day for adult females.
ALT:  At least 1.5 mg of vitamin B2 per day; most suggest 25-50 mg of vitamin B2 per day. 
TOX:  No toxic or adverse effects of high riboflavin intake in humans are known.  Excess is believed to be excreted.

Return to Vitamin Directory

Vitamin B3

Vitamin B3-1 (niacin) Vitamin B3-2 (niacinamide)  –  A water-soluble B-complex vitamin that functions as a coenzyme that is involved in energy production, lipid metabolism, oxidation-reduction (redox) reactions, is a functional part of non-redox coenzyme reactions (such as NAD and NADP), plays a role in intracellular calcium release regulation, and appears to function in DNA repair and stress responses, cell-signaling (communication between cells), DNA transcription (copying), apoptosis (programmed cell death), and cell differentiation (cell change for specific functions that tend to decrease rapid cell division, which suggests a possible role in the prevention of certain conditions where rapid cell division is an integral part).  Niacin (nicotinic acid), which, in supplement form tends to cause an itchy skin flush, has been used to help control cholesterol levels but at intake levels that do so has been shown to adversely affect the liver, with time-release forms most easily causing liver damage.  Niacinamide (nicotinamide), which is a derivative of niacin, has many of the same health benefits as niacin (but not cholesterol lowering) but does not cause a skin flush.  In supplement form, niacinamide is generally better tolerated than niacin.  Niacinamide (but not niacin) is thought to be useful for improving the memory (possibly even combating memory loss associated with aging), is thought to help support the immune system by boosting the number and effectiveness of neutrophils (white blood cells), is believed to help support joint structures and a sense of balance, helps support overcoming fatigue and muscle weakness, and may help relieve exercise-induced muscle soreness in amounts up to 1,500 mg per day in divided doses of 250 mg each, with the total daily intake amount depending upon the severity of the muscle soreness (Reference: Alternatives, Feb. 2009, Vol. 12, No. 20, and Alternatives, Nov. 1997, Vol. 7, No. 5, which are based on the work conducted by niacinamide research pioneer Dr. William Kaufman).  However, a high intake of niacinamide may increase homocysteine levels due to it using up methyl donors, which may negatively impact cardiovascular health.  When consumed in the diet, the amino acid tryptophan (abundant in fish and seafood, poultry, soybeans, and other protein-based foods) can be converted to niacin in the body with the assistance of vitamin B6.  In spite of similar names, nicotinic acid (niacin) and nicotinamide (niacinamide) are not related to nicotine that is present in tobacco. 
Deficiency:  Photosensitive dermatitis, diarrhea and dementia, which are symptoms of “pellagra” (a known deficiency condition).
Food Sources:  Tuna, salmon, chicken, turkey, legumes and seeds, with fortified cereals containing the most niacin.  In mature grains, such as corn and wheat, niacin is bound to sugar molecules, which significantly decreases niacin’s bioavailability. 
RDA:  16 mg of niacin per day for adult males, and 14 mg of niacin per day for adult females. 
UL:  35 mg of niacin per day. 
ALT:  20 mg per day for niacin; 50 mg per day for niacinamide.
TOX:  Common side effects of niacin in supplement form are skin flush and upset stomach, and sometimes skin rash and dry skin.  Large doses of niacin impairs glucose tolerance (which is bad news for those with blood sugar problems) and causes liver damage, including elevated liver enzymes and jaundice with intakes as low as 750 mg per day of immediate-release niacin, and hepatitis with intakes as little as 500 mg per day of time-release niacin.  The people most susceptible to the adverse effects of high doses of niacin are believed to be those with a history of liver problems, blood sugar problems, GI tract problems, joint problems, heartbeat problems, inflammatory bowel problems, recurring headaches, and alcoholism.  Niacin (but not niacinamide) has been used to help control blood cholesterol and triglyceride levels with a dose of niacin of 2-3 grams (2,000-3,000 mg) per day.  However, it is such high doses of niacin (especially with concurrent statin drug use) that greatly increases the risk of liver damage, cardiomyopathy (heart muscle damage), and rhabdomyolysis (painful muscle wasting where muscle cells are broken down, releasing muscle enzymes and electrolytes into the blood that can lead to kidney failure).  Unlike niacin, niacinamide is believed to be non-toxic in amounts up to 1,500 mg per day when taken in divided doses of 250 mg each, taken 2-3 hours apart, but such a high daily dose may use up methyl donors and thus cause an increase in homocysteine levels which may negatively impact cardiovascular health.  High dose niacin and niacinamide should only be taken under doctor supervision.

Return to Vitamin Directory

Vitamin B5

Vitamin B5 (pantothenic acid)  –  A water-soluble B-complex coenzyme vitamin that supports energy production and nerve function, is a functional part of CoA and acyl-carrier proteins, and is involved in fatty acid synthesis and metabolism.  Vitamin B5 is usually referred to as pantothenic acid, its chemical name.  Pantothenic acid is a vital component of coenzyme A (CoA), which is required for chemical reactions that generate energy from food, for the synthesis of essential fats, cholesterol, steroid hormones and the vitally important neurotransmitter acetylcholine (a neurotransmitter is a chemical that is released by a nerve cell that transmits an impulse to another nerve cell or structure such as an organ or muscle), and is involved in the oxidation of pyruate (a ketone body used in energy production in the Krebs cycle, aka the citric acid cycle).  The Krebs cycle (which is the fundamental source of energy production in nearly all cells in the human body) is a complex series of chemical reactions that takes place within cells, where oxygen is utilized as part of the cellular respiration process, that converts biochemical energy from nutrients into the production of the energy molecule adenosine triphosphate (ATP) and also carbon dioxide as a waste product.  While ATP is primarily derived from the metabolic breakdown of glucose (known as glycolysis) that originated from ingested carbohydrates, dietary fats and protein can also be used as energy sources.  Pyruvate is produced during the metabolism of carbohydrates and is an integral part of glycolysis, the breakdown of glucose to pyruvate that ultimately results in the release of usable energy in the form of ATP from the Krebs cycle.  The Krebs cycle takes place inside the cell’s mitochondria (the dynamic cellular “power plant” organelle), of which there are several mitochondria within each cell – all of which produce ATP and power cellular function.  Pantothenic acid works closely with the other B-complex vitamins in energy production (and several other functions).  Pantothenic acid plays a principal role in acetylated protein reactions (acyl-carrier proteins or acetylation) that affects the physical structure of proteins and alters the activity of peptide hormones (which are hormones made from protein, such as insulin, as opposed to steroid hormones which are made from cholesterol).  Acetylated proteins play a role in cell division and DNA replication, affects gene expression (DNA coded information that is transcribed and translated to proteins and other cell structures such as RNA), and plays a central role in cell-signaling (communication between cells).  Pantothenic acid is required for the synthesis of fatty acids (a component of lipids, which are fatty acids, phospholipids, triglycerides, and sterols such as cholesterol), which are needed for such things as part of the protective myelin sheaths that cover and insulate nerves, and as an important and protective part of the structure of cell membranes.  Pantothenic acid in supplement form is commonly seen as pantothenol (a more stable derivative form which is rapidly converted to pantothenic acid in the body).  Also seen in supplements are the calcium pantothenate form and the sodium pantothenate form.  A non-vitamin derivative of pantothenic acid known as pantethine has been used (principally in Europe and Japan) for its cholesterol-lowering effect at doses of 300 mg taken three times a day (for a total of 900 mg per day) under doctor supervision.  Pantethine is generally thought to be well-tolerated up to 1,200 mg per day but can cause gastric upset, and with continuous long-term use may possibly affect the health and function of the liver similar to high-dose niacin and statin drugs (but, nonetheless, is seen as a possible better alternative to the use of high-dose niacin and statin drugs).
Deficiency:  Peripheral nerve damage manifesting as numbness and tingling (and sometimes pain and a burning sensation) in the hands and feet.  A gross deficiency is rare and usually only seen in starvation or severe malnutrition/absorption conditions. 
Food Sources:  Avocado, yogurt, chicken, sweet potato, milk, egg yolk and legumes. 
RDA:  None established. 
AI:  5 mg of pantothenic acid per day. 
RDI:  5 mcg of pantothenic acid per day. 
ALT:  5 mg of pantothenic acid per day, up to 50 mg of pantothenic acid per day. 
TOX:  Pantothenic acid is generally considered non-toxic but adverse reactions have occurred with high doses in some people, with gastric upset and diarrhea being the most common side effect.  In an unusual situation, 300 mg of pantothenic acid taken with 10 mg of biotin a day for two months is known to have caused a life-threatening condition affecting the membranes that surround the heart and lungs of an elderly woman (a condition known as eosinophilic pleuropericardial effusion).  The non-vitamin pantethine derivative form of pantothenic acid should only be taken under the guidance of a qualified healthcare practitioner.

Return to Vitamin Directory

Vitamin B6

Vitamin B6 (pyridoxine)  –  A water-soluble B-complex coenzyme vitamin that supports the metabolism of protein amino acids and glycogen (stored glucose), modulates the actions of steroid hormones decreasing their effects, supports the immune system, and helps regulate homocysteine blood levels.  There are six chemical forms of vitamin B6 used in the body, with pyridoxine being the source of vitamin B6 found in supplements.  Vitamin B6 plays a vital role in over 100 enzymes that catalyze essential chemical reactions in the human body.  Vitamin B6 functions as a coenzyme that catalyzes the release of glucose from glycogen stored in muscles, in reactions used to generate glucose from amino acids, in the synthesis of neurotransmitters such as serotonin, dopamine, norepinephrine and gamma-aminobutyric (GABA), in the synthesis of heme (the iron-containing component of hemoglobin, which is the oxygen-transporting molecule of the red blood cells), is involved in the synthesis of the nucleic acids DNA and RNA, assists the amino acid tryptophan convert to niacin in the body, works with folic acid and vitamin B12 to help regulate homocysteine levels in the blood (homocysteine is an intermediate byproduct of methionine metabolism, raised blood levels of which have been associated with an increased risk for cardiovascular problems), and plays a role in inhibiting steroid hormones, thus decreasing their effects, which suggests that vitamin B6 status may have implications for conditions affected by steroid hormones (such as breast and prostate problems). 
Deficiency:  Disorders of amino acid metabolism and in the systems where vitamin B6 acts as a coenzyme, elevated blood levels of homocysteine, neurologic symptoms such as irritability, depression, confusion, and even convulsions with a severe deficiency (which is uncommon), and inflammation of the tongue and ulcers in and around the mouth. 
Food Sources:  Potato (with skin), chicken, salmon, spinach, banana and turkey. 
RDA:  1.7 mg of vitamin B6 per day for adult males, and 1.5 mg of vitamin B6 per day for adult females. 
UL:  100 mg of vitamin B6 per day. 
ALT:  2.0 mg of vitamin B6 per day, up to 75 mg of vitamin B6 per day. 
TOX:  Supplemental amounts of 500 mg or more of vitamin B6 per day can cause sensory neuropathy, which is characterized by pain and numbness in the feet.  Long-term intake amounts in excess of 200 mg of vitamin B6 per day may eventually lead to peripheral nerve damage.  The UL of 100 mg of vitamin B6 per day is thought to provide an adequate safety margin, especially since there are no known health benefits above that intake level.

Return to Vitamin Directory

Vitamin B12

Vitamin B12 (cobalamin, cyanocobalamin)  –  A water-soluble B-complex coenzyme vitamin that supports the nervous system, red blood cells, energy production, brain function (may help prevent memory problems), helps regulate homocysteine blood levels (with the assistance of folic acid and vitamin B6), and helps prevent canker sores (with 1,000 mcg taken sublingual at bedtime).  Vitamin B12 has the largest and most complex chemical structure of all the vitamins, with it being unique in that it contains a mineral, cobalt, hence its chemical name cobalamin.  The form of vitamin B12 used in most supplements is cyanocobalamin, which is readily converted to vitamin B12 activity in the body.  Vitamin B12 is required for the function of the folic acid dependent enzyme (methionine synthase) that is required for the metabolism of homocysteine into the amino acid methionine, with this biological process known as methylation.  Homocysteine is a sulfur intermediate byproduct of methionine metabolism that can undergo auto-oxidation in the blood, produce free radicals that can damage the endothelial cells that line the interior of the arteries and promote oxidation of LDL cholesterol and triglycerides, and is especially prevalent in those with kidney problems.  Methylation is used in many biological reactions, including a number of sites within DNA and RNA.  Methylation of DNA is currently thought to possibly be an important aspect in the prevention of certain serious conditions, while it helps prevent the accumulation of homocysteine in the blood which is associated with an increased risk of cardiovascular problems.  In addition to the vitamin B12 methyl donor (methylcobalamin, an especially active form), other phytochemicals that supply methyl donor groups include dimethylglycine (DMG) and trimethylglycine (TMG) which also contribute to the methylation process.  Vitamin B12 plays an important role in the production of energy from fats and protein, and is required for the synthesis of the oxygen-carrying pigment in red blood cells hemoglobin.  There is a significant relationship between B12 and the B-complex vitamin folic acid (the taking of supplemental folic acid can mask a vitamin B12 deficiency).  Food and supplement amounts of vitamin B12 are especially difficult to absorb as we age, with sublingual supplement forms that dissolve under the tongue thought to help overcome this difficulty. 
Deficiency:  About 10% – 15% of those over the age of 60 are thought to be vitamin B12 deficient.  Decreased stomach acid production (necessary for vitamin B12 release from food) and the taking of gastric acid inhibitors (such as Pepsid, Tagamet, Tums, and Zantac) decrease vitamin B12 absorption.  A vitamin B12 deficiency can lead to anemia (low or hemoglobin-deficient red blood cells), specifically pernicious anemia (an autoimmune condition which is actually the end-stage of the destruction of stomach cells that produce gastric acid and enzymes necessary for the release of vitamin B12 from food), and megaloblastic anemia (a condition where both vitamin B12 and folic acid are rendered unavailable to participate in DNA synthesis, which causes the bone marrow to produce immature and hemoglobin-poor red blood cells).  Vitamin B12 deficiency is known to damage the protective myelin sheath that covers the cranial nerves of the brain (which can lead to memory problems), and the spinal and peripheral nerves (leading to numbness and tingling sometimes in the arms and hands but usually in the legs and feet that can cause difficulty in balance and walking) which is thought to be a contributory factor (along with peripheral artery problems) in the shuffle-walk seen in the elderly.  An uncorrected vitamin B12 deficiency can cause irreversible nerve damage.  Gastrointestinal (GI) problems can cause vitamin B12 deficiency (and other nutrient deficiencies).  Common GI tract problems include gastritis (which is thought to affect 10% – 30% of those over the age of 60) and malabsorption syndrome (such as celiac condition, i.e., an abnormal immune reaction to gluten, a protein found in wheat and related grains such as rye and barley, that damages the nutrient-absorbing villi of the small intestine causing a disruption in nutrient uptake that results in nutrient deficiencies, diarrhea and anemia).  (See “Folic Acid” listing below.)
Food Sources:  Animal foods and seafood, especially clams, mussels, crab, salmon and beef.  There is no vitamin B12 in plant foods, thus it is prudent for strict vegetarians (vegans) to take vitamin B12 in supplement form.
RDA:  2.4 mcg of vitamin B12 per day.
ALT:  It is generally recommended that those who are 50 years of age or older should take vitamin B12 in dietary supplement form of at least 100 mcg per day, up to 500-1,000 mcg per day.  In several clinical studies, 500 mcg per day of folic acid decreased homocysteine blood levels by 25%, and further reduced homocysteine blood levels by 32% with the addition of 500 mcg per day of vitamin B12 (which demonstrates the synergy of vitamin B12 and folic acid).  However, it is presently unknown if decreasing homocysteine blood levels will translate to a reduction in the risk for cardiovascular problems (which is suspected), with studies continuing.  Recent clinical studies have demonstrated the prevention of canker sores (recurrent aphthous stomatitis) with the sublingual taking at bedtime of 1,000 mcg of vitamin B12.  Sublingual vitamin B12 is believed to be the best supplement form for uptake.
TOX:  No known toxic or adverse effects have been associated with large doses of vitamin B12 intakes up to 1,000 mcg (1 mg) per day in healthy people.  Because of its stimulating effect, taking B12 too close to bedtime may interfere with sleep.  Excess supplemental B12 intakes that are above the RDA may cause skin rash and other skin problems in some people.  In rare occurrences excess intakes of B12 in supplement form may overly stimulate nerve transmissions which may produce an irregular heartbeat, and because of its ability to stimulate cell growth it may not distinguish between stimulating normal cell growth and stimulating abnormal cell growth which can be highly problematic. 

Return to Vitamin Directory

Folic Acid

Folic Acid (folate, vitamin B9)  –  A water-soluble B-complex coenzyme vitamin that is vital for DNA and RNA synthesis, prevents neural tube birth defects (with adequate daily intakes at least one month before and one month after conception), prevents megaloblastic anemia (a condition where both folic acid and vitamin B12 are rendered unavailable to participate in DNA synthesis, which causes the bone marrow to produce enlarged, immature and hemoglobin-poor red blood cells), and works with vitamin B6 and especially vitamin B12 to help regulate homocysteine blood levels.  Although the terms are often used interchangeably, folate is actually the naturally occurring form found in food, while the more commonly used term folic acid is actually the chemical derivative form used in supplements (with the folic acid supplement form being about 70% more bioavailable than folate).  Folic acid (with the assistance of vitamin B12) is required for the metabolism of homocysteine into the amino acid methionine, a process known as methylation.  Methylation is used in many biological reactions, including within DNA and RNA.  Methylation of DNA is currently thought to possibly be an important aspect in the prevention of certain serious conditions, while it helps prevent the accumulation of homocysteine in the blood which is associated with an increased risk of cardiovascular problems.  Elevated homocysteine blood levels with decreased folic acid and vitamin B12 levels have been associated with memory problems, especially in older adults.
Deficiency:  Folic acid has an interrelationship with vitamin B12.  A folic acid deficiency can mask a vitamin B12 deficiency, which is relatively common in those over 60.  Megaloblastic anemia (which is where oxygen-carrying red blood cells are not properly formed and manifests as weakness, fatigue and shortness of breath) can be caused by folic acid deficiency and also by vitamin B12 deficiency.  Adequate supplementation with folic acid can restore normal red blood cell formation in megaloblastic anemia, however, if vitamin B12 deficiency is the actual underlying cause of the anemia then the vitamin B12 deficiency will continue despite the resolution of the anemia by folic acid.  An uncorrected vitamin B12 deficiency can cause irreversible nerve damage.  A folic acid deficiency also manifests as elevated homocysteine blood levels.  Because the taking of folic acid supplements can mask a vitamin B12 deficiency, it is considered important to take vitamin B12 daily (especially in sublingual form) when taking folic acid supplements (see “Vitamin B12” listing above).
Food Sources:  Plant foods, especially leafy green vegetables (i.e., “foliage” which is the basis for the name folate), asparagus, spinach, citrus fruit juices, tomato juice, legumes (beans, peanuts, peas, soybeans, and especially lentils, garbanzo beans and lima beans), and “fortified” cereals.  “Fortification” of certain processed foods was mandated by the U.S. government to restore certain nutrients lost in processing, beginning in 1943 with small amounts of thiamine, riboflavin, niacin and iron added to milled flour products (such as “enriched” white bread), with folic acid fortification added to certain foods beginning in 1998 for women of childbearing age to prevent neural tube birth defects in their babies, which has been credited with an approximate 50% reduction of such birth defects seen in the U.S.  Because of this and several studies, folic acid is now considered critical for normal embryonic development.
RDA:  400 mcg of folic acid per day for adults.
UL:  1,000 mcg (1 mg) of folic acid per day for adults.
ALT:  800 mcg of folic acid per day for adults.
TOX:  5,000 mcg (5 mg) of folic acid per day has produced irreversible neurologic damage.  The naturally occurring folate in food has no known toxicity.  Folic acid in supplement form has produced adverse effects when taken with the regular consumption of alcoholic beverages, and at high intakes of supplemental folic acid even without alcoholic beverage consumption.  Low folate intake (from food) with concurrent intake of alcohol (two or more drinks per day) is associated with an increased incidence of serious colorectal problems.  It is known that alcohol interferes with the normal uptake of folate (in food), and also with folic acid (in supplement form or in folic acid fortified foods).  It is currently thought that the intake of 600 mcg per day of folic acid may help reduce the risk of certain serious breast conditions, but not in those women who consume two or more alcoholic drinks a day.  It is believed that two or more alcoholic drinks per day doubles the risk of serious colorectal problems, while 650 mcg of folic acid per day is thought to possibly help nullify that increased risk.  However, it is believed that high doses of folic acid of 1,000 mcg (1 mg) or more a day may increase the risk of serious prostate problems, and may also accelerate tumor growth.  Therefore, it would seem prudent to not consume more than 800 mcg of folic acid per day from all sources combined (in supplement form and from fortified foods), with no such restrictions in consuming folate that naturally occurs in food.

Return to Vitamin Directory


Biotin (vitamin B7)  –  A water-soluble B-complex coenzyme vitamin that supports energy production and healthy skin, hair and nails.  When biotin attaches to certain protein molecules (in a process known as histone biotinylation) it plays an important role in regulating DNA transcription (copying the DNA code), replication and cellular proliferation.  As a cellular enzyme cofactor (coenzyme), biotin is essential in several metabolic reactions, such as fatty acid synthesis, regulating fatty acid oxidation in the mitochondria (the cell’s energy-producing power plant), is critical in the formation of glucose (gluconeogenesis) from amino acids and fatty acids, and supports cholesterol metabolism.  Biotin helps stimulate the synthesis of the stored form of glucose (glycogen) and helps stimulate the secretion of insulin from the pancreas.
Deficiency:  Although very rare, an overt deficiency of biotin includes skin and scalp dermatitis, hair loss, brittle nails, a characteristic skin rash around the face and in the genital area, and neurologic symptoms that can affect the mental state (such as depression, lethargy and even hallucination) and numbness and tingling of the extremities (especially fingers and toes).
Food Sources:  Biotin is widely distributed in food but generally in small amounts, with egg yolk and liver being the richest sources, and is fairly abundant in salmon, avocados, pork and whole wheat.
RDA:  None established.
AI:  30 mcg of biotin per day for adults.  It is believed that marginal (i.e., subclinical) biotin deficiency may be relatively common in pregnancy and may be a factor in abnormal embryo and/or fetus development that may result in certain types of birth defects.  Thus, in addition to 400 mcg of folic acid a day before and during pregnancy, it is generally thought prudent to also include 30 mcg a day of biotin.
ALT:  300 mcg of biotin per day for adults.
TOX:  No known adverse or toxic effects of biotin up to 10,000 mcg (10 mg) per day in most people.  However, in an unusual situation, 10 mg of biotin taken with 300 mg of pantothenic acid taken a day for two months is known to have caused a life-threatening condition affecting the membranes that surround the heart and lungs of an elderly woman (a condition known as eosinophilic pleuropericardial effusion).  There are no known toxic effects of biotin from food, and there appears to be no biological reason to exceed 300 mcg per day of biotin in supplement form for those in normal health who do not have a predisposing hereditary caused biotin deficiency (which should only be treated by a medical doctor).

Return to Vitamin Directory

Vitamin C

Vitamin C (ascorbic acid)  –  A water-soluble antioxidant vitamin that supports the normal function and structure of the vascular system (blood vessels), immune system, collagen production and repair, joint and bone health, gum health, eye health and brain function, enhances iron absorption, may help regulate blood cholesterol levels, and is especially beneficial for the cardiovascular system.  Ascorbic acid is the chemical name for vitamin C.  Ascorbic acid from plant sources (typically derived from corn) is the natural source of vitamin C used in some supplements, however there appears to be no difference in vivo (in the human body) between natural-source vitamin C and chemical ascorbic acid.  Vitamin C is vital in collagen synthesis (formation).  Collagen is an important structural component of blood vessels, tendons, ligaments and bone – it is the cement that holds the body together.  Vitamin C is important in the synthesis of the neurotransmitter norepinephrine, which is one of the neurotransmitters that are critical for brain function and which affect mood.  Vitamin C is required for the synthesis of carnitine which is essential for the transport of fatty acids within the cell for conversion of fat into energy by the cell’s mitochondria (the energy-producing organelles within each cell, commonly referred to as the cell’s “power plant,” which is the seat of metabolic energy).  Vitamin C is a highly effective antioxidant, protecting such things as proteins, carbohydrates, fats and nucleic acids (DNA and RNA) from damage by free radicals and reactive oxygen species generated during normal metabolism and also from exposure to environmental toxins and pollutants (such as cigarette smoke).  Vitamin C reinvigorates other antioxidants, especially revitalizing vitamin E antioxidant activity.  Vitamin C and vitamin E have a strong synergy together, especially benefiting the vascular system.  Vitamin C is considered the most vascular-healthy nutrient there is.  Vitamin C has a strong synergy with certain cardiovascular-healthy bioflavonoids, such as citrus bioflavonoid complex (containing hesperidin, naringin and eriocitrin) found in citrus fruits, rose hips (technically not a bioflavonoid itself but has bioflavonoid activity in addition to having the highest concentration of vitamin C and is the edible seed pod portion of roses not typically seen due to pruning), quercetin (which is thought to have antihistamine properties and is abundant in the skin of red apples and red onions), and rutin (abundant in buckwheat, is a quercetin glycoside, i.e., quercetin bound to sugar molecules, that is thought to help reduce capillary fragility, especially associated with hemorrhoids).  Vitamin C helps support normal blood pressure, and also helps support exercise-induced muscle fatigue recovery.  Vitamin C, especially with rose hips, has a strong synergy with the essential mineral magnesium.
Deficiency:  Overt vitamin C deficiency results in “scurvy” a potentially fatal condition (unless corrected) where collagen production is disrupted and manifests as subcutaneous hemorrhage (bleeding into the skin giving a bruised appearance, and bleeding from mucous membranes), loss of dental cement resulting in spongy gums and loose teeth, and impaired wound healing.  In addition to bleeding gums and being a contributory factor in weak bones and joints, minimal vitamin C intake of long duration results in subclinical scurvy (aka “sub-scurvy”) which weakens the blood vessels by lessening their structural integrity making them more susceptible to damage and dystrophic calcification.  Recent research points to the structural weakening of the arteries from long-standing sub-scurvy as the precursor to damage of the endothelial cells that line the arteries (caused by unbalanced calcium metabolism), which leads to dystrophic calcification.  It is not completely certain what role a deficiency of bioflavonoids (the plant pigments largely responsible for the color of fruits, flowers, vegetables, beans, seeds and certain grains) may play, but because it is generally thought that they exert a beneficial impact on health they therefore are important to include in the diet primarily by consuming a varied diet based on plant foods.
Food Sources:  Plant foods, especially citrus fruits and their juice, red bell peppers, strawberries and broccoli.
RDA:  90 mg of vitamin C per day for adult males, and 75 mg of vitamin C per day for adult females (amounts of 10-35 mg per day are thought to prevent/remedy scurvy).  The RDA for smokers is 125 mg of vitamin C per day for adult males, and 110 mg of vitamin C per day for adult females.
UL:  2,000 mg of vitamin C per day for adults.
ALT:  400 mg of vitamin C (which is thought adequate to completely saturate cells) to 1,000-6,000 mg of vitamin C per day (which is thought to take on a clinical role rather than just a nutritional role at such intake levels).  Because of its beneficial impact on vascular health, vitamin C is believed to have a profoundly beneficial impact on cardiovascular health – especially when vitamin C is taken with the heart-healthy essential mineral magnesium.  A new form of vitamin C (called “Lypo-Spheric Vitamin C”), which is said to have “Maximized Bio-Availability” (unsubstaniated), is nothing more than vitamin C blended with phospholipids (the type of fat-like lipid that is found in soy lecithin), and in use has been found to cause or increase GI tract distress (manifesting as diarrhea), may be an endocrine disruptor because of its soy-based phytoestrogen content, and may cause or contribute to skin eruptions in some people (part of the problem may be that it is taken on an empty stomach and it contains 12% alcohol).  Doctor administered high-dose intravenous (IV) administration of 10-100 grams (10,000 mg to 100,000 mg) of vitamin C has been used as an adjunct to certain therapies and infections, and to help offset exposure to or buildup of certain toxins.  Such IV administered vitamin C is thought may have abnormal cell growth cytotoxic effects (while not affecting normal cells), and may help reduce inflammation markers (such as those assoicated with cardiovascular, breast and prostate problems).  While promising, the use of IV administered vitamin C remains controversial and not fully scientifically substantiated at this time.  (Reference: “Vitamin C, Infectious Diseases, & Toxins” by Thomas E. Levy, M.D., J.D.; and “Effect of High-Dose Intravenous Vitamin C on Inflammation…” Journal of Translational Medicine, Sept. 11, 2012, Vol. 10, page 189) 
TOX:  Oral vitamin C intake is generally considered safe up to 10,000 mg (10 grams) per day for adults in good health.  High oral doses of vitamin C may cause gastric upset or diarrhea, which can generally be avoided if intakes are increased very gradually and taken in divided doses spread throughout the day.  It is generally recommended that those predisposed to oxalate kidney stone formation avoid high-dose vitamin C intakes.  At one time it was thought that it was prudent to gradually reduce high oral intakes of vitamin C that have been taken for a long duration to prevent the possibility of a rebound-type effect (commonly referred to as “rebound scurvy”).  However, research has failed to document that this actually occurs with the discontinuance of high doses of vitamin C, and the anecdotal reports of “rebound scurvy” are believed to be scientifically unfounded.  On the other hand, gradually discontinuing high doses of vitamin C that has been taken for a long duration is not known to cause any harm.

One of the many things that vitamin C does is to support the normal function of the immune system.  Research by Dr. Linus Pauling, and by other researchers more recently, has shown that vitamin C supplementation stimulates the production and concentration of certain immune system antibodies in the blood, while at the same time preventing the seasonal (Winter) decline of certain other antibodies, thus supporting how the immune system functions.  Regular hand washing and “PARSNIP” may also help to prevent the spread of seasonal conditions.  PARSNIP is an acronym for the Prevention And Reduction of Seriously Nasty Infectious Pathogens, which is the rationale for reconsidering the social convention of hand shaking as a greeting, especially during the Winter or during outbreaks of potentially deadly conditions such as H1N1.  Perhaps just a simple greeting of “PARSNIP” would be a better alternative, which also serves to let the other person know that you respect their health.  Just saying “PARSNIP” shows that you are aware and care.

Return to Vitamin Directory

Vitamin D

Vitamin D (cholecalciferol, ergocalciferol)  –  A fat-soluble pro-hormone (misnamed as a vitamin) that assists in the absorption of calcium and other minerals, supports bone mineralization, supports the immune system, and supports cardiovascular health.  (A pro-hormone has no hormone activity itself, but is converted in the body to a molecule that does.)  Vitamin D affects the uptake and function of minerals, especially the minerals calcium, magnesium, phosphorus, et al.  Too little vitamin D has a negative impact on the uptake of calcium and magnesium, while too much vitamin D can contribute to dystrophic calcification and can induce a magnesium deficiency.  The hormone molecule of vitamin D is 25-hydroxyvitamin D, aka 25(OH)D, and 1alpha, 25-dihydroxyvitamin D, aka 1,25(OH2)D, which are blood biomarkers used to evaluate vitamin D status in the body – with 25(OH)D being the marker to determine the vitamin D level in the blood (aka: calcidiol blood test).  The most beneficial vitamin D blood level range is currently thought to be 30-40 nanograms per milliliter of blood (30-40 ng/ml), with 40 ng/ml generally considered optimal (30-40 ng/ml = 75-100 nmol/L).  It is currently thought that a total daily intake of 2,000 IU of vitamin D will generally raise blood levels to approximately 40-60 ng/ml, and such blood levels may significantly reduce the risk of certain forms of breast and colorectal problems (Reference: Annals of Epidemiology, 2009, #19, pages 468-483).  Low blood levels of vitamin D (15-30 ng/ml), and especially very low blood levels (less than 15 ng/ml), have recently been thought to be linked to poor cardiovascular health and may carry with it a greater risk of heart and blood vessel problems (Reference: Intermountain Medical Center Research Team, Salt Lake City, Utah, as reported by, Feb. 6, 2010).  Recent research appears to have uncovered a positive association between vitamin D blood levels and dystrophic calcification in the carotid artery and aorta of the subjects tested (Reference: The Journal of Clinical Endocrinology & Metabolism, Vol. 95, No. 3, pages 1076-1083, Mar. 2010).  Vitamin D appears to have a U-shaped curve in regards to its effects, that is, too little or too much appear to have negative health consequences (Reference: University of Copenhagen, Faculty of Health and Medical Services; ”Vitamin D: Too Much Can Be As Unhealthy As Too Little” reported in Medical News Today, May 30, 2012, published in The Journal of Clinical Endocrinology and Metabolism).  Skin exposure to ultraviolet radiation from sunlight, specifically the UVB rays, stimulates cholecalciferol (vitamin D3) production, while it is UVA radiation that is most dangerous to the skin.  Vitamin D3 is naturally found in fish oil, and is the form most commonly used in dietary supplements.  Ergocalciferol (vitamin D2) is formed in plants exposed to sunlight and is a less active form.  Vitamin D3 is known to be at least three times more potent than vitamin D2.  Vitamin D supports normal bone density and strength, helps regulate at least 50 genes in tissues, is involved in cell differentiation (cell change from a non-specific generalized form to a specialized form that is specific for a particular tissue, organ or other body part that in so doing tends to decrease overly rapid cell division, which suggests a role in the prevention of conditions where rapid cell division occurs), is believed to help support cardiovascular health by helping to prevent dystrophic calcification (calcium deposits in soft tissues) if the intake amount is not too little (less than 800 IU per day) or too much (more than 2,000 IU per day) on an ongoing daily basis, and is believed to act as an immune system modulator in certain autoimmune responses by modulating T-cell response (such as where insulin-producing beta cells of the pancreas are attacked and destroyed by immune system T-cells, where myelin-producing cells of the central nervous system are attacked and destroyed, and where collagen-producing cells of joints are attacked and destroyed).  It is now thought that vitamin D supports the healthy function of the insulin-producing beta cells of the pancreas and thus may play a role in correcting the main defect in certain conditions (Reference: “Super Vitamin…” by Dr. Allen Spreen,, July 30, 2011).  Vitamin D supports the immune system by activating infection-fighting T-cells, and is believed to be useful for common seasonal infections typical in Winter.  It is thought that when a T-cell recognizes a foreign invader, such as bacteria or viruses, it sends activating signals to the vitamin D receptor gene which stimulates the production of a protein (known as the PLC-gamma 1 protein) that triggers the T-cell’s ability to fight the infection.  Adequate amounts of vitamin D are associated with a reduced risk of bone fracture, and health issues that can affect the breasts, prostate, and GI tract (especially the colorectal region).  Researchers have recently discovered that vitamin D3 appears to inhibit both the production and function of a specific protein identified as cMYC (which is known to drive abnormal cell division), as well as to stimulate production of a natural antagonist of cMYC known as MXD1.  (Reference: Proceedings of the National Academy of Sciences, McGill University, Canada, May 2013.)  Inadequate Intake (less than 600 IU per day) or Excess Intake (more than 2,000 IU per day on an ongoing basis) of vitamin D can mobilize calcium from bones (weakening them), causing excess calcium to enter the bloodstream (called hypercalcemia), which strongly contributes to unbalanced calcium metabolism and dystrophic calcification (calcium deposits), especially in the cardiovascular system and kidneys.  Vitamin D is known as the “sunshine vitamin,” with sunlight interacting with the skin surface to produce it.  Medically supervised exposure to ultraviolet radiation (or sunlight exposure for about 10 minutes a day) is known as “phototherapy” (or light therapy) and is used for certain skin conditions, such as psoriasis, and may be beneficial for skin “barnacles” (benign seborrhea keratosis) common in older adults who have limited exposure to sunshine, not to be confused with precancerous actinic keratosis which is caused by excess sun exposure that has occurred over many years, with this commonly known as “sun damage.”  Skin cells that have sun damage have been known to improve with topical applications of coconut oil and also with topical Manuka honey.
Deficiency:  Lack of adequate vitamin D causes “rickets” (abnormal bone formation due to lack of proper bone mineralization), especially in children, and in adults causes soft bones, myopathy (muscle weakness), muscle cramps (especially of the legs and feet), and heartbeat arrhythmias (irregular heartbeat) – due to improper calcium use.  Lack of vitamin D causes the parathyroid glands to secrete an increase in parathyroid hormone (known to be critical for the metabolism of the major bone minerals calcium and phosphorus) which results in increased bone resorption (breakdown of calcium phosphate and deposits calcium into the bloodstream), weakening bones.  Lack of vitamin D contributes to muscle and heart weakness, especially noticeable in the elderly and infants, because its unavailability prevents its normal interaction with the mineral calcium (to produce normal muscle contractions) and with the mineral magnesium (to produce normal muscle relaxation).  Ironically, too much vitamin D can also cause weak bones (by mobilizing calcium from bone), and heart and muscle weakness (by depleting magnesium that is needed for normal heart and muscle function).  Risk factors that can cause a vitamin D deficiency include: Dark skin (less able to produce vitamin D from sunlight), limited exposure to sunlight (5-10 minutes exposure, three times a week, is generally considered adequate to prevent a vitamin D deficiency with minimal risk of sun damage to the skin), aging (the ability of older adults to produce vitamin D from sunlight exposure is impaired), excess dietary fat intake, malabsorption conditions of the GI tract, and obesity (more vitamin D is deposited in stored body fat making less of it available for normal use).  Too much or too little vitamin D is now considered a strong contributory factor in unbalanced calcium metabolism and dystrophic calcification.
Food Sources:  Fish liver oil, fatty fish (such as salmon and sardines), egg yolks, and fortified foods (such as milk).  Some fish are known to be too contaminated (with mercury and PCBs, both by-products of industrial processes) to be healthful sources of vitamin D (or omega-3s), and include: King mackerel, shark, swordfish, and tilefish (generally, the bigger fish).  Better choices include salmon (especially wild-caught salmon), sardines, halibut, sole, and yellowfin tuna.  Supplemental Source:  Because vitamin D is a fat-soluble vitamin it should be taken in an oil-based form, with vitamin D3 from mercury-free fish liver oil considered the best supplemental source.  When taking vitamin D in supplement form it is important to maintain an “intake balance” with the essential mineral magnesium to prevent a magnesium deficiency and to help prevent dystrophic calcification.
RDA:  Not established due to varied sunlight exposure conditions, skin type, age, and various other considerations.  (See RDI)
AI:  600 IU of vitamin D per day for adults.
UL:  2,000 IU of vitamin D per day for healthy adults.
RDI:  600 IU Daily Value of vitamin D per day to age 70, and 800 IU Daily Value of vitamin D per day age 71+ (recently updated from 400 IU/day).
ALT:  800-1,000 IU of vitamin D per day for adults (thought to reduce the risk of bone loss) up to 2,000 IU of vitamin D per day for adults (thought to afford some protection from colorectal conditions).  Many alternative doctors recommend 1,000 IU per day on an ongoing daily basis, up to a maximum of 2,000 IU of per day for 7-10 days to boost the immune system.  Some researchers recommend up to 3,000 IU of vitamin D per day for African-Americans, and up to 6,000 IU per day during pregnancy and lactation (Reference: “Official Recommended Intake for Vitamin D is Too Low” by William B. Grant, PhD, Orthomolecular Medicine News Service, Feb. 19, 2010).  Some alternative doctors recommend up to 5,000 IU of vitamin D per day for short periods (7-10 days) to boost the immune system for certain health conditions.  Some doctors have reported a significant reduction in the duration and symptoms associated with common seasonal (Winter) conditions by taking 5,000 IU of vitamin D with elderberry syrup daily for about a week.
TOX:  Amounts in excess of 10,000 IU of vitamin D per day may have adverse or toxic effects.  Excess vitamin D can induce hypercalcemia (high blood calcium), kidney stone formation, dystrophic calcification, and a magnesium deficiency.  Some researchers believe that supplemental intakes below 600 IU and above 2,000 IU of vitamin D per day, on an ongoing basis, may be a contributory factor in mobilizing calcium from bone, which weakens the bones and contributes to unbalanced calcium metabolism and dystrophic calcification.  Excess vitamin D supplementation may mobilize calcium from bones and dump it into the bloodstream.  Excess calcium in the bloodstream can cause dysfunction and damage to the endothelial cells that line the arteries, with such endothelial cell dysfunction and damage triggering dystrophic calcification and being a strong contributory factor in conditions that affect the cardiovascular system and kidneys.  Excess blood calcium increases the risk of kidney stone formation, and may increase the risk of irreversible kidney damage.  A Word of Caution: There is emerging evidence that suggests that: “Vitamin D supplementation may be contraindicated in those with autoimmune disorders, tuberculosis (TB), chronic obstructive pulmonary disease (COPD), sarcoidosis, granulomatous diseases, adenoma of the parathyroid gland, and some lymphomas.”  Initial research with vitamin D (which is actually a “secosteroid” pro-hormone rather than an actual vitamin) has provided symptomatic improvement (such as inflammation suppression, which would be expected from a secosteroid) in those with autoimmune conditions.  However, because it is suspected that pathogens may be involved in some if not all autoimmune conditions, or may influence their progression, the use of vitamin D supplementation may only temporarily suppress the activity of the pathogen early-on – but the pathogen may actually proliferate over the long-term, resulting in markedly increased symptoms later (Reference: Autoimmunity Research Foundation, “Low Levels Of Vitamin D In Patients With Autoimmune Disease May Be Result, Not Cause, Of The Disease,” Science Daily, April 9, 2009).  It is thought by some researchers that vitamin D supplementation of 600 IU to 1,000 IU per day (or skin exposure to sunshine of about 10 minutes a day by those with a light complexion, or a little longer in those with a dark complexion), in those with autoimmune conditions, may not be enough vitamin D to cause or contribute to this potential risk, but those with these conditions should be guided by their doctor.  Excess intake of cod liver oil can supply vitamin D (as well as vitamin A) in amounts thought to be toxic.

An excess intake of vitamin D can induce a magnesium deficiency.  Hence, it is deemed prudent to have an adequate intake of magnesium when vitamin D supplements are taken (Reference: “Know the Importance of Taking Enough Magnesium with Your Vitamin D” Natural, by Kerri Knox, RN, July 14, 2010).  Because of the interaction between vitamin D and magnesium (and their interaction with calcium) it is deemed prudent to maintain an “intake balance” between them when taken in concentrated supplement form to prevent a magnesium deficiency (and to prevent dystrophic calcification).  Example: If taking 1,000 IU of vitamin D3 daily then it would be prudent to also take at least 1,000 mg of magnesium daily for proper utilization of both.

Return to Vitamin Directory

Vitamin E

Vitamin E (tocopherol, tocotrienol)  –  A family of eight fat-soluble antioxidant vitamins that supports the cardiovascular system, blood circulation, and cellular membrane health.  Vitamin E in dietary supplements that is labeled as d-alpha tocopherol is “natural” vitamin E and has about twice the biological activity than the same amount of synthetic vitamin E which is labeled as dl-alpha tocopherolTocopherol is the primary form of vitamin E found in food.  Mixed tocopherols that contain the full-spectrum of tocopherols (alpha, beta, gamma and delta) are thought to be the most beneficial.  The “alpha” form is known to be the most biologically active form, and is the only form that remains active in the human body.  Tocotrienol is a different form of vitamin E that has a slightly different chemical structure than tocopherol.  Like tocopherol vitamin E, tocotrienol vitamin E is also composed of alpha, beta, gamma and delta components known as isomers (i.e., the same basic substance but with a different chemical structure having different properties that results in a different biological activity level, with the tocotrienol “alpha” isomer also being the most biologically active form).  The biological activity of tocotrienol vitamin E is only about 28% of tocopherol vitamin E, but nonetheless acts as an adjunct by rounding out and providing a full-spectrum of vitamin E activity.  Among its many other activities, recent research suggests that the tocotrienol form of vitamin E (which is naturally found in palm oil, whole grains and rice bran) may increase hair growth in those with male pattern baldness (the inherited gene expression androgenetic alopecia, the cause of 95% of all cases of hair loss), which occurs in about 25% of men starting at age 30 and in two-thirds of men by age 60 (in the study 100 mg of tocotrienol per day, taken for 8 months, demonstrated an average 42% increase in hair growth, but in spite of that was not seen as a “cure” for baldness).  As an antioxidant, vitamin E protects cell membranes from free radicals, which are formed during normal cellular metabolism and from exposure to environmental factors (such as cigarette smoke and air pollution).  In addition to cell membranes, vitamin E also protects from oxidation other structures that contain fat such as the protective myelin sheath that surround nerves, and other lipids such as triglycerides (blood fat) and low-density lipoprotein (LDL) cholesterol.  Basically, vitamin E protects fats from oxidation.  Vitamin E has a strong antioxidant synergy with vitamin C (and CoQ10).  When vitamin E neutralizes free radicals it loses its antioxidant capacity.  However, other antioxidants, most notably vitamin C, can regenerate vitamin E antioxidant capability.  Vitamin E is involved in cell-signaling (communication between cells), beneficially affects immune system activity, inhibits blood platelet aggregation (stickiness), and enhances vasodilation (blood vessel expansion) and blood flow (with the aid of vitamin C and the essential mineral magnesium).  Studies have demonstrated a profound beneficial influence on maintaining normal arterial functional flexibility by taking vitamin E (800 IU) and vitamin C (1,000 mg) just before consuming a fat-laden meal, which if consumed without taking the vitamins tends to cause arterial rigidity and a reduction in functional flexibility (which can last up to four hours after a meal).  Alpha-tocopheryl acetate and alpha-tocopheryl succinate are esters (a chemical reaction product) of tocopherols that are sometimes used in vitamin E supplements because of being more resistant to oxidation during storage than unesterified tocopherols.  When taken orally, the acetate and succinate portions separate away in the intestines leaving the vitamin E as bioavailable as alpha tocopherol vitamin E.
Deficiency:  Although rare, an overt deficiency of vitamin E can cause neurological symptoms, cellular and immune system dysfunction, and health and functional problems with the cardiovascular system.  A slight to moderate deficiency of vitamin E may cause an increase in the risk of cardiovascular problems.  Marginal vitamin E deficiency is thought to be very common, with about 90% of Americans thought to not get at least the RDA because the amount of vitamin E naturally present in food is small.
Food Sources:  Plant and seed oils (such as sunflower, safflower, canola, olive, corn and soybean oils), nuts (especially almonds and hazelnuts), legumes (especially peanuts), avocados, whole grains and seeds.  The vitamin E naturally present in food (and used in some supplements) is natural vitamin E.  The vitamin E used in “fortified” food (and in some supplements) is typically synthetic vitamin E.
RDA:  23 IU of natural alpha tocopherol vitamin E per day for adults.
UL:  1,500 IU of natural alpha tocopherol vitamin E per day for adults.
ALT:  200 IU of d-alpha tocopherol (natural) vitamin E per day for adults (or 400 IU every other day), up to a maximum of 800 IU of d-alpha tocopherol (natural) vitamin E per day for adults.  Synthetic vitamin E (dl-alpha tocopherol) has about half the biological activity as natural vitamin E (d-alpha tocopherol).
TOX:  Amounts of natural vitamin E of 2,000 IU per day is believed to increase the risk of all-cause mortality (death from all causes), while no such risk is associated with 200-800 IU of natural vitamin E per day.  An intake of 1,000 IU or more of natural vitamin E per day may interfere with the uptake of the other fat-soluble vitamins (vitamins A, D and K).  Because vitamin E has a blood thinning effect (and because high doses may interfere with vitamin K uptake) it should not be taken without doctor supervision and is considered prudent to discontinue its use at least several days before surgical procedures.  Likewise, those who are vitamin K deficient, or have a bleeding condition (such as hemophilia), or take anticoagulant drugs (such as Coumadin® ), or take anti-platelet drugs (such as Plavix® ), or take NSAIDs, i.e., non-steroidal anti-inflammatory drugs (such as aspirin and ibuprofen), should only take vitamin E under medical supervision to reduce the risk of hemorrhage (bleeding).  (Coumadin is the registered trademark of Bristol-Myers Squibb Co.; Plavix is the registered trademark of sanofi-aventis, a partner with Bristol-Myers Squibb Co.)  400 IU of vitamin E per day has been found to increase the progression of a genetic eye condition known as “retinitis pigmentosa” which can lead to blindness.  Some studies have suggested that supplemental vitamin E may increase the risk of hemorrhagic stroke (a bleeding stroke), while other studies have indicated that supplemental vitamin E may reduce the risk of ischemic stroke (a blood vessel blockage stroke); (at about 80% of all strokes, ischemic stroke is the most common).  Supplemental vitamin E of 200 IU per day (or 400 IU every other day) is generally deemed safe in healthy adults, as a balance between not increasing the risk of hemorrhagic stroke while helping to reduce the risk of ischemic stroke (blood vessel strengthening bioflavonoids such as provided by rose hips and rutin may also help reduce the risk of a hemorrhagic stroke).  Vitamin E naturally present in food is not known to produce any adverse effects or toxicity.

Return to Vitamin Directory

Vitamin K

Vitamin K (phylloquinone K1, menaquinone K2, menadione K3)  –  A family of fat-soluble coenzyme vitamins that support normal blood coagulation and blood clotting (K1), normal bone matrix mineralization and cardiovascular function (K2), cell growth regulation, and is involved in cell-signaling activities (communication between cells).  The vitamin K name is derived from “koagulation,” the German word for coagulation.  Phylloquinone is natural vitamin K1 and is formed in growing plants, and is the primary source for vitamin K in the western diet.  Menaquinone is natural vitamin K2 and is formed in a natural 10:1 ratio (10 parts K1 produces 1 part K2) in the human body by the action of friendly bacteria in the intestines on phylloquinone (vitamin K1), and along with its unique formation pathway is believed to have unique biological functions that are not yet fully understood.  Vitamin K2 is also naturally found in certain fermented foods.  Menadione is synthetic vitamin K3 and its use has largely been discontinued these days due to its tendency to produce adverse effects that were discovered when administered to infants, which includes oxidative damage to cell membranes as a result of vitamin K3 interfering with the function of glutathione (a potent antioxidant that is naturally produced in the body), rupture of red blood cells, and causing liver toxicity and damage that results in jaundice.  However, vitamin K3 has been used in adults in large doses (50 mg of vitamin K3 with 5,000 mg of vitamin C in a pharmaceutical preparation known as Apatone) which was thought may help make chemotherapy drugs more effective.  Vitamin K is an important factor in the regulation and proper use of the mineral calcium (K1 in the blood coagulation process), and may help balance calcium metabolism (K2 in bone mineralization and normal cardiovascular function).  Vitamin K is an enzymatic cofactor that catalyzes the carboxylation (sparks the introduction of carbon dioxide) of glutamic acid (an amino acid) that is critical to the calcium-binding aspect of the blood coagulation process.  Vitamin K and calcium are critical to blood clotting.  Vitamin K1 is the vitally important factor in a series of events (known as the blood coagulation cascade pathway) that stops bleeding through blood clot formation, and also provides control and balance to prevent uncontrolled blood clotting.  Both uncontrolled bleeding and uncontrolled blood clotting are life threatening.  Blood coagulation factors that are dependent on vitamin K are synthesized (made) in the liver.  Liver damage or disease can interfere with this process and lower blood levels of vitamin K dependent blood clotting factors.  Thus, liver damage or disease can increase the risk of uncontrolled bleeding.  Anticoagulant drugs such as Coumadin® (warfarin) inhibit coagulation by interfering with the vitamin K cycle in the blood coagulation cascade pathway, which inhibits blood clot formation.  This is the reason why those who take anticoagulant drugs have their blood clotting time monitored on a regular basis, which is known as prothrombin time (PT), also known as “pro-time.”  In addition to measuring the clotting tendency of blood, PT blood tests (often used in conjunction with a PTT blood test, i.e., a partial thromboplastin time blood test) are also used to evaluate the function of all the blood coagulation factors (Factor I, II, V, VII and X), and is used to check for liver damage and vitamin K status.  The usual reference range for PT time is about 12-15 seconds in healthy adults but such range can vary somewhat from lab to lab.  Increased PT times may be due to bile duct obstruction (which prevents bile from breaking down dietary fat and its uptake along with the fat-soluble vitamins A, D, E and K), chronic liver conditions, the taking of anticoagulant drugs, a vitamin K deficiency, or a condition known as “disseminated intravascular coagulation” (which is where the proteins that control blood clotting become abnormally active and as a result cause abnormal blood clot formation throughout the body, and when those blood clotting proteins become exhausted it dramatically increases the risk of highly visible subcutaneous bleeding throughout the body – not to be confused with the vitamin C deficiency condition of scurvy).  Vitamin K also plays a role in bone strength and the normal function of the cardiovascular system and the kidneys by helping to regulate the proper use of the mineral calcium.  It is thought that proteins dependent on vitamin K work in a synergistic fashion with vitamin D in bone metabolism that affects bone matrix mineralization and bone density, and thus bone strength.  Inadequate vitamin K is thought to compromise bone density by not allowing normal bone matrix mineralization, which causes the mineral calcium to slowly migrate out of bones (weakening them) and enter the bloodstream (contributing to unbalanced calcium metabolism which can affect the cardiovascular system, kidneys, and eyes).  Studies suggest that one of the vitamin K dependent proteins (known as MGP) may help prevent dystrophic calcification (calcium deposits in soft tissues), especially the calcium deposits that tend to accumulate around heart valves and buildup in the arteries and kidneys.  Thus, diets rich in vitamin K1 (naturally present in certain plant foods) and vitamin K2 (naturally present in certain fermented foods) may help prevent dystrophic calcification.  Another vitamin K dependent protein (known as Gas6) is thought to be involved in a diverse range of important cellular functions, including cell adhesion and proliferation, and may afford some protection from apoptosis (programmed cell death).  It is also thought that Gas6 regulates platelet signaling (involved in blood coagulation and blood clot formation), and plays a role in maintaining vascular homeostasis (the normal functional balance of the blood vessels).  Diets that are especially rich in leafy green plant foods, which is the natural source for vitamin K (as well as having a host of other beneficial nutrients), may help support proper blood flow and blood vessel function, may help support bone density and strength, may help prevent dystrophic calcification, and may help slow apoptosis (cell death) and thus slow the aging process.  The vitamin K family is distinguished by their side-chains (i.e., their basic molecular structure), which are of varying lengths.  Recent research suggests that the longer side-chains of vitamin K2 (which have the designation MK-7, MK-8, and MK-9) are thought to be beneficial for the cardiovascular system and bone health, especially vitamin K2 with the MK-7 side-chain, by helping to normalize calcium use – that is, helping to keep excess calcium out of the bloodstream and in the bones where it belongs for normal function – thus helping to prevent dystrophic calcification and weak bones.  Vitamin K2 with the MK-7 side-chain is naturally present in certain fermented foods, such as sauerkraut, certain cheeses (the Dutch cheeses Edam and Gouda), and especially natto (a rather strong-tasting Japanese fermented soybean food, not to be confused with the fibrin-controlling enzyme Nattokinase dietary supplement which is derived from natto but has had the vitamin K content removed).  Recent research suggests that only a small intake of vitamin K2 MK-7 (about 1-2 mcg/day) may afford a degree of protection from certain cardiovascular conditions and support bone health, however, more in-depth research is needed to clearly delineate the benefits and define optimal intake levels.  Because of the naturally occurring synergy of function between certain nutrients, vitamin K2 MK-7, as it naturally occurs in certain foods, may one day prove to be a useful adjunct to the cardiovascular health benefits demonstrated by Potentiated Magnesium (pMg).  However, there are some problems with the regular (daily) intake of the foods that naturally contain vitamin K2 MK-7.  Sauerkraut is too acid-forming for daily consumption (acid-forming foods have been associated with certain health problems), Edam and Gouda cheeses contain too much saturated animal fat and excess calcium (which have been associated with cardiovascular health problems), and natto (the richest natural source of vitamin K2 MK-7) is not readily available outside of Japan and has a particularly strong and unfamiliar taste for the western palate.  There are also some problems with the supplemental form of vitamin K2 MK-7.  Vitamin K supplements are contraindicated in those who have cardiovascular health issues, dystrophic calcification, or are prone to blood clots.
Deficiency:  A vitamin K deficiency will result in the loss of normal blood clotting and increase the risk of bleeding (mimicking the genetic disorder hemophilia), and causes easy subcutaneous bleeding (bleeding under the skin that resembles deep bruising).  Overt vitamin K deficiency is uncommon in healthy adults, primarily because it is widespread in food, and also because of the friendly bacteria that normally inhabit the intestines where vitamin K2 is synthesized from ingested vitamin K1 in plant foods.  Also, once ingested, vitamin K is conserved as it is recycled in the vitamin K cycle during normal usage.  Those most at risk of a vitamin K deficiency are those who take anticoagulant drugs, those with significant liver damage or disease, those with dietary fat absorption disorders (because of being a fat-soluble vitamin, vitamin K requires some dietary fat for its uptake), and those who consume a diet void of plant foods, especially avoiding dark-green leafy vegetables.
Food Sources:  Vitamin K is naturally present in food and is primarily found in plant foods, and is especially rich in dark-green leafy vegetables with small amounts in some vegetable oils (canola, olive and soybean oils).  The richest plant sources of vitamin K1 include: Swiss chard, kale, broccoli, spinach, kelp, mustard greens, and green leaf lettuce.  The richest food source of vitamin K2 that have the longest side-chains (MK-7, MK-8, and MK-9) is from certain fermented foods, specifically Japanese natto, sauerkraut, and certain cheeses (Edam and Gouda).  Hydrogenated oils inhibit the absorption and biological effects of vitamin K.  Vitamin K as is naturally present in food, especially leafy green vegetables, is generally considered its best source (and is considered a better and safer source than vitamin K supplements).
RDA:  No RDA for vitamin K has been established.
AI:  120 mcg of vitamin K per day for healthy adult males, and 90 mcg of vitamin K per day for healthy adult females – from food.  It is thought that diets that are high in leafy green vegetables provide adequate vitamin K, and such a diet is considered especially important as we age to provide the body with the nutrients it needs for proper function and health.
ALT:  Vitamin K supplementation is generally considered unnecessary in healthy adults who consume a plant-based diet.  It is believed that 250 mcg of vitamin K a day (the amount of vitamin K1 in ½ cup of chopped broccoli or in a large salad of mixed greens, which converts to 25 mcg of vitamin K2) may confer a degree of protection from age-related bone loss and weakening, and is associated with a decreased risk of hip fracture in mature adults.  However, evidence of a relationship between high-dose vitamin K supplementation and bone health in adults is considered weak at best.  While it has been speculated that a lack of vitamin K in the diet may play a role in vascular dystrophic calcification, it remains unclear exactly what the nature of that role may be.  Recent research suggests that vitamin K2 MK-7 may play a role in calcium metabolism.  Strong evidence from recent research points to unbalanced calcium metabolism as the underlying culprit in dystrophic calcification.  The only substance capable of balancing calcium metabolism is the essential mineral magnesium.
TOX:  No known adverse effects or toxicity is associated with natural vitamin K1 – from ingested plant foods – or with vitamin K2 that is naturally produced in the intestines from vitamin K1 with the aid of the friendly bacteria that normally reside in the intestines.  Vitamin K in supplement form is known to increase the risk of cardiovascular events and blood clots (specifically being prone to readily form blood clots).  Synthetic vitamin K3 has documented serious adverse effects, especially in infants.  Large doses of vitamin E (1,000 IU or more per day), or large doses of the other fat-soluble vitamins (vitamins A and D), may interfere with vitamin K absorption, especially in those on anticoagulant drug therapy.  Prolonged use of broad spectrum antibiotics (which kill friendly intestinal bacteria) may decrease the intestinal synthesis of vitamin K2.  It is unknown what adverse effects there are with the regular or long-term intake of supplemental vitamin K MK-7 in healthy adults.  Vitamin K supplements should not be taken without the guidance of a knowledgeable medical doctor.

Vitamins have a strong synergy with minerals.

Return to Table of Contents

Terms & Conditions |     Privacy Policy |    Disclaimer

This entry was posted in (2) Nutrient Resource Section. Bookmark the permalink.

Comments are closed.