Through diet and a daily multivitamin and mineral formula taken with a meal. B7 (also known as 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 full 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. If you are diagnosed as biotin deficient, your doctor will prescribe the proper amount as a medicine.