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vitamin B6What can foods high in vitamin B6 do for you?
What events can indicate a need for more high-vitamin B6 foods ?
Excellent sources of vitamin B6 include bell peppers, turnip greens, and spinach.
What is vitamin B6?First researched in the mid-1930's, vitamin B6 is one of the best-studied of all B vitamins and has one of the greatest varieties of chemical forms. The forms of this vitamin all begin with the letters "pyr," and include pyridoxine, pyridoxal, pyridoxamine, pyridoxine phosphate, pyridoxal phosphate, and pyridoxamine phosphate. The vitamin was not originally given this name, however, but was referred to as "antidermatitis factor." This term pointed to the skin (dermis) because skin inflammation (dermatitis) seemed to increase when foods with B6 were eliminated from the diet. Topical B6 creams are used to this day in treatment of skin inflammation, particularly in relationship to symptoms of seborrheic dermatitis. What is the function of vitamin B6?Much of the body's chemistry depends upon enzymes. Enzymes are proteins that help chemical reactions take place. Because vitamin B6 is involved with more than 100 enzymatic reactions, its function in the body is diverse and far-reaching. Synthesis of essential moleculesIt is difficult to find a chemical category of molecules in the body that do not depend in some way on vitamin B6 for their production. Many of the building blocks of protein, called amino acids, require adequate supplies of B6 for synthesis. Nucleic acids used in the creation of DNA in our genes also require this vitamin. Because amino acids and nucleic acids are such critical parts of new cell formation, vitamin B6 can be regarded as an essential part of the formation of virtually all new cells in the body. Heme (the protein center of our red blood cells) and phospholipids (our cell membrane components that allow messaging between cells) also depend on vitamin B6 for their creation. Processing of carbohydrateThe processing of carbohydrate (sugar and starch) in our body depends on availability of vitamin B6. This vitamin is particularly important in facilitating the breakdown of glycogen (a special form of starch) stored in our muscle cells and to a lesser extent in our liver. Because carbohydrate processing plays such a key role in certain types of athletic events, researchers have looked closely at the role vitamin B6 plays in carbohydrate processing during physical performance. Support of nervous system activityThe role of vitamin B6 in our nervous system is very broad, and involves many aspects of neurological activity. One aspect focuses on the creation of an important group of messaging molecules called amines. The nervous system relies on formation of these molecules for transmission of messages from one nerve to the next. (The molecules can be classified as "neurotransmitters" for this reason.) Amines are one type of neurotransmitter in the nervous system. They are often made from parts of protein called amino acids, and the key nutrient for making this process happen is vitamin B6. Some of the amine-derived neurotransmitters that require vitamin B6 for their production include serotonin, melatonin, epinephrine, norepinephrine, and GABA. Support of sulfur and methyl metabolismThe movement of sulfur-containing molecules around the body is especially important for hormonal balance and elimination of toxic substances through the liver. Because vitamin B6 is able to remove sulfur groups from other molecules, it helps the body maintain flexibility in handling sufur-containing compounds. Vitamin B6 plays a similar role with respect to methyl-containing molecules. The term "methyl group" refers to a chemical structure that has only one carbon atom and three hydrogen atoms. Many important chemical events in the body are made possible by the transfer of methyl groups from one place to another. For example, genes in the body can be switched on and turned off in this way, and cells can use the process to send messages back and forth. The attachment of methyl groups to toxic substances is one way of making them less toxic and encouraging their elimination from the body. It is also a way of ensuring that substances like homocysteine, which can build up excessively in the blood and lead to risk of cardiovascular disease, are kept within a healthy range. Deficiency SymptomsWhat are deficiency symptoms for vitamin B6? Because of its key role in the formation of new cells, vitamin B6 is especially important for healthy function of body tissue that regenerates itself quickly. The skin is exactly this type of tissue, and it is one of the first to show problems when B6 is deficient. Many skin disorders have been associated with B6 deficiency, and they include eczema and seborrheic dermatitis. The key role of vitamin B6 in the nervous system also results in many nerve-related symptoms when B6 is deficient. These symptoms can include convulsions and seizures in the case of severe deficiency. The critical role of vitamin B6 in the formation of red blood cells means that B6 deficiency can also result in symptoms of anemia, malaise, and fatigue. When anemia is exclusively related to B6 deficiency, it is usually classified as hypochromic, microcytic (pernicious) anemia. Toxicity SymptomsWhat are toxicity symptoms for vitamin B6? Imbalances in nervous system activity have been shown to result from high levels of supplemental vitamin B6 intake. These imbalances do not seem to occur until supplementation exceeds 2 grams per day. The National Academy of Sciences has set a Tolerable Upper Intake Level (UL) for vitamin B6 of 100 milligrams for adults 19 years and older, largely based on the issue of imbalanced nervous system activity described above. Impact of Cooking, Storage and Processing How do cooking, storage, or processing affect vitamin B6? Although historically described as one of the most stable of the B vitamins, large amounts of vitamin B6 are lost during most forms of cooking and processing. Loss of B6 from canning of vegetables is approximately 60-80%; from canning of fruits, about 38%; from freezing of fruits, about 15%; from conversion of grains to grain products, between 50-95%; and from conversion of fresh meat to meat by-products, 50-75%. When food is heated in the context of simple home cooking, the acidity of the food often determines how much B6 is lost or retained. In general, the more acidic the food, the poorer the B6 retention. Also, in the context of the home kitchen, the freezing of foods high in B6 can result in the loss of approximately 1/3 to 1/2 of the total B6 content. Because foods high in B6 are typically not eaten raw, a good solution to these processing problems is to consume plentiful amounts of foods high in B6. Factors that Affect FunctionWhat factors might contribute to a deficiency of vitamin B6? In addition to dietary insufficiency, smoking and the use of many prescription medications can contribute to vitamin B6 deficiency. Medications that deplete the body's supply of B6 are listed in the medications section of this nutrient profile. What medications affect vitamin B6? A long list of prescription medications has been linked to depletion of the body's B6. These medications include birth control pills and oral estrogens; diuretics, including furosemide; barbiturates, including phenobarbitol and phenytoin; anti-epileptic drugs, including carbamazepine; asthma-related drugs, including theophylline; aminoglycosides, including gentamicin used for bacterial infection; tuberculosis drugs, including isoniazid and rifampin; and anti-fibrotic drugs, including beta-aminopropionitrile. Nutrient InteractionsHow do other nutrients interact with vitamin B6? As a member of the B vitamin family, B6 has key interactions with many of its family members. B6 is essential for making vitamin B3 (niacin) from the amino acid tryptophan. In Down's syndrome, for example, some of the problems related to vitamin B3 deficiency appear to be lessened by intake of vitamin B6. Vitamins B2 and B3 are both needed to convert vitamin B6 into its various chemical forms, and imbalances in vitamin B1 metabolism create imbalances in vitamin B6 metabolism. B6 deficiency can also reduce the body's absorption of vitamin B12. Health ConditionsWhat health conditions require special emphasis on vitamin B6? Vitamin B6 may play a role in the prevention and/or treatment of the following health conditions::
What forms of vitamin B6 are found in dietary supplements? Vitamin B6 is most commonly sold in the form of pyridoxine hydrochloride (pyridoxine HCl). However, alternative forms of the vitamin, for example, pyridoxal-5-phophate, are also widely available and often preferred by healthcare practitioners since they constitute the biologically active forms of the vitamin. Individuals who are not experiencing health benefits from supplementation with pyridoxine hydrochloride, or who have a history of liver problems that might prevent activation of pyridoxine, should consider supplementation with pyridoxal-5-phosphate. Introduction to Nutrient Rating System ChartThe following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents; the nutrient density rating; and the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. Read detailed information on our Nutrient Rating System. Public Health RecommendationsWhat are the current public health recommendations for intake of vitamin B6? In 2000, the National Academy of Sciences established Recommended Dietary Allowances for vitamin B6 for all individuals 1 year and older, and Adequate Intake (AI) levels for infants under 1 year of age. These recommendations are as follows:
Articles about vitamins Vitamin B6
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Glutamine
- L-Glutamine 05
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Lysine
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Energizer texts
Triblus
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