B vitamin
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B vitamin supplement tablets

The B vitamins are eight water-soluble vitamins that play important roles in cell metabolism. Historically, the B vitamins were once thought to be a single vitamin, referred to as vitamin B (much like how people refer to vitamin C or vitamin D). Later research showed that they are chemically distinct vitamins that often coexist in the same foods. Supplements containing all eight are generally referred to as a vitamin B complex. Individual B vitamin supplements are referred to by the specific name of each vitamin (e.g. B₁, B₂, B₃ etc ).

List of B vitamins

• Vitamin B₁ (thiamine)
• Vitamin B₂ (riboflavin)
• Vitamin B₃ (niacin, includes nicotinic acid and nicotinamide)
• Vitamin B₅ (pantothenic acid)
• Vitamin B₆ (pyridoxine, pyridoxal, and pyridoxamine)
• Vitamin B₇ (biotin), also known as vitamin H
• Vitamin B₉ (folic acid), also, vitamin M
• Vitamin B₁₂ (various cobalamins; commonly cyanocobalamin in vitamin supplements)

Former or unclassified vitamins

• Vitamin B₄ (adenine, DNA metabolite) is no longer classified as a vitamin because it is synthesized by the human body^{citation needed}
• Vitamin B₈ (myo-inositol, adenylic acid, DNA metabolite) is no longer classified as a vitamin because it is synthesized by the human body^{citation needed}

B vitamin deficiency

Several named vitamin deficiency diseases may result from the lack of sufficient B-vitamins. Deficiencies of other B vitamins result in symptoms that are not part of a named deficiency disease.

Related nutrients

Many of the following substances have been referred to as vitamins because they were believed to be vitamins at one time, and they are relevant to vitamin nomenclature in that the numbers that were assigned to them form "gaps" in the series of B-vitamin names. Some of them, though not essential to humans, are essential in the diets of other organisms; others have no known nutritional value.

• Vitamin B₄: Adenine, a nucleobase.¹
• Vitamin B₇: "Vitamin I" of Centanni E. (1935) — also called 'Enteral factor' — is a water and alcohol soluble rice-bran factor which prevents digestive disturbance in pigeons. It governs the anatomical and functional integrity of the intestinal tract. Later found in yeast. Possible candidates for this substance are inositol, niacin (nicotinic acid), and biotin. Carnitine was also claimed to be a candidate but is not soluble in alcohol.^{citation needed}
• Vitamin B₈: adenosine monophosphate, or alternately inositol has also been called vitamin B₈
• Vitamin B₁₀: para-aminobenzoic acid, or PABA
• Vitamin B₁₁: Pteryl-hepta-glutamic acid – Chick growth factor, which is a form of Folic acid. Later found to be one of five folates necessary for humans; also known as Vitamin S or Factor S. (L-carnitine) is called Vitamin B₁₁ in France^{citation needed}.
• Vitamin B₁₃: Orotic acid.
• Vitamin B₁₄: cell proliferant, anti-anemia, rat growth, and antitumor pterin phosphate named by Earl R. Norris (biochemist of folic acid fame). Isolated from human urine at 0.33ppm (later in blood), but later abandoned by him as further evidence did not confirm this. He also claimed this was not Xanthopterin.
• Vitamin B₁₅ 6-O-(dimethylaminoacetyl)-D-gluconic acid (Pangamic acid)
• Vitamin B₁₆ (dimethylglycine) – also known as DMG. (However Lipoic acid was discovered and named a B-Vitamin after B15 and before B17)
• Vitamin B₁₇ (Amygdalin, Nitrilosides, or laetrile) – A substance found in a number of seeds, sprouts, beans, tubers and grains. While toxic in large quantities, proponents claim that it is effective in cancer treatment and prevention. ²
• Vitamin B₁₈ –
• Vitamin B₁₉ –
• Vitamin B₂₀ (Carnitine) –
• Vitamin B₂₁ –
• Vitamin B₂₂ – often claimed as an ingredient of Aloe vera extracts but also in many other foods. Claimed by one source to be Vitamin B12b-δ.
• Vitamin B_h – another name for Biotin
• Vitamin B_m ("mouse factor") – also used to designate Inositol
• Vitamin B_p (Choline) –^{dubious – discuss} Choline is only required for survival of some mutants. Most commonly it is synthesized in vivo de novo ³ May be added as supplement especially when methionine supply is limited.
• Vitamin B_t (L-carnitine) –
• Vitamin B_v – a type of B₆ but not Pyridoxine
• Vitamin B_w – a type of Biotin but not d-Biotin
• Vitamin B_x – another name for PABA (para-Aminobenzoic acid)
• Lipoic acid –

Note: B₁₆, B₁₇, B₁₈, B₁₉, B₂₀, B₂₁ & B₂₂ do not appear to be animal factors but are claimed by some naturopaths as human therapedic factors.

Health benefits

The B vitamins often work together to deliver a number of health benefits to the body. B vitamins have been shown to:

• Support and increase the rate of metabolism
• Maintain healthy skin and muscle tone
• Enhance immune and nervous system function
• Promote cell growth and division — including that of the red blood cells that help prevent anemia.
• Reduce the risk of pancreatic cancer, one of the most lethal forms of cancer⁴, when consumed in food, but not when ingested in vitamin tablet form.⁵⁶

Together, they also help combat the symptoms and causes of stress, depression, and cardiovascular disease.

All B vitamins are water soluble, and are dispersed throughout the body. Most of the B vitamins must be replenished daily, since any excess is excreted in the urine.⁷ A six year cobalamin store can be found in the liver, despite its water soluble nature.[4]

Vitamin B sources

Different B vitamins come from different natural sources, such as potatoes, bananas, lentils, chile peppers, tempeh, liver oil, liver, turkey, tuna, Nutritional yeast (or brewer's yeast) and molasses. Marmite and Vegemite bill themselves as "one of the world's richest known sources of vitamin B". As might be expected, due to its high content of brewer's yeast, beer is a source of B vitamins⁸, although this may be less true for filtered beers⁹and the alcohol in beer impairs the body's ability to activate vitamins.

The B-12 vitamin is of note because it is not available from plant products, making B-12 deficiency a concern for vegans. Manufacturers of plant-based foods will sometimes report B-12 content, leading to confusion about what sources yield B-12. The confusion arises because the standard US Pharmacopeia (USP) method for measuring the B-12 content does not measure the B-12 directly. Instead, it measures a bacterial response to the food. Chemical variants of the B-12 vitamin found in plant sources are active for bacteria, but cannot be used by the human body. This same phenomenon can cause significant over-reporting of B-12 content in other types of foods as well.¹⁰

Vitamin B may also be delivered by injection to reverse deficiencies.¹¹

Another popular means of increasing one's vitamin B intake is through the use of dietary supplements purchased at supermarkets, health centers, or natural food stores. B vitamins are also commonly added to energy drinks. Many energy drinks have been marketed with large amounts of B vitamins ("5-Hour Energy contains an astounding 8,333% of the recommended dietary allowance of vitamin B-12 and 2,000% of the RDA for vitamin B-6.… Red Bull…offers 360% of the RDA for vitamin B-6, 120% of B12, 140% of niacin (vitamin B3)"¹²) with claims that this will cause the consumer to "sail through your day without feeling jittery or tense." ¹² Nutritionists, such as Professor Hope Barkoukis, dismiss these claims "It's brilliant marketing, but it doesn't have any basis [in fact]."¹² While B vitamins do "help unlock the energy in foods…Just about everyone in America already gets all of the B vitamins they could possibly need in their diets… Extra B vitamins are generally just flushed out of the system - although everyone's limit of absorption is different in regards to B complex vitamins and no-one knows how much is needed on an individual basis of these vitamins…"¹² While the elderly and athletes may need to supplement their intake of B-12 and other B vitamins due to problems in absorption and increased needs for energy production, for "most typical consumers of energy supplements or drinks, B vitamins are nothing more than a 'gimmick' when they are making these false claims."¹²

Mnemonic

One mnemonic to remember the most commonly referenced B vitamins is "The Rhythm Nearly Proved Contagious" (B1 - Thiamine; B2 - Riboflavin; B3 - Niacin; B6 - Pyridoxine; B12 - Cobalamin).¹³

See also

• Bee pollen

References

External links

• How B Vitamins Work at HowStuffWorks