Vitamin B7 is also known as biotin, which is necessary for energy production, cell growth, production of fatty acids, and the metabolism of fats and amino acids. It plays a primary role in all of our cells’ energy production by being an integral player in the citric acid cycle where biochemical energy is generated as we breathe. Biotin is often recommended for strengthening hair and nails. Little evidence exists that it can deliver on this recommendation unless someone was deficient, which would be very rare in developed nations. Biotin deficiency is rare because in normal health our intestinal bacteria produce it in excess of the body's daily requirements, which are only about 30-100mcgs/day. That said, there are individuals with abnormal metabolism of biotin, which can lead to certain metabolic disorders. In this case they may be treated by a qualified physician with biotin therapy. Biotin sources include Swiss chard, eggs (mainly the yolk), liver, some vegetables and supplements. Most daily multivitamin and mineral formulas (MVM) contain all the biotin necessary (and probably a little more) for normal healthy people. Although biotin deficiencies are rare, marginal deficiencies have been shown in certain populations such as during pregnancy, athletes, dieters, elderly, alcoholics, and burn patients, which can lead to decreased energy production and other biotin related functions. For this reason we always recommend a daily MVM to all populations containing between 100-300mgs of biotin (B7). Active people maintaining low body fat may do better at the higher part of this range.