B VITAMINS

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 as 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 ). Different B vitamins come from different natural sources, such as potatoes, bananas, lentils, chile peppers, tempeh, beans, 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 vitaminsalthough this may be less true for filtered beers and 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

Vitamin B may also be delivered by injection to reverse deficiencies. 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)" with claims that this will cause the consumer to "sail through your day without feeling jittery or tense." Nutritionists, such as Professor Hope Barkoukis, dismiss these claims "It's brilliant marketing, but it doesn't have any basis [in fact]."

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.