Biotin: Vitamin H, more commonly known as biotin, is a water-soluble vitamin produced in the body by certain types of intestinal bacteria and obtained from food. Considered part of the B complex group of vitamins, biotin is necessary for the metabolism of carbohydrates, fats, and amino acids (the building blocks of protein).

Deficiency, uncommon in humans, may result in hair loss, dry scaly skin, cracking in the corners of the mouth (called cheilitis), swollen and painful tongue that is magenta in color (glossitis), dry eyes, loss of appetite, fatigue, insomnia, and depression. Animals deficient in biotin during pregnancy are more likely to deliver newborns with birth defects such as a cleft palate. Research in this area for pregnant women is underway. One situation in which biotin deficiency does often develop is in people who have been on parenteral nutrition (nutrition administered intravenously rather than through the mouth or stomach) for a long period of time. It may also been seen in people who have been on long-term therapy with anticonvulsants, antibiotics, and sulfa drugs.

Interestingly, vegetarians are able to absorb more biotin from the gastrointestinal tract than meat eaters. Biotin is often recommended for strengthening hair and nails and is found in many cosmetic products for hair and skin.

These foods contain a significant amount of biotin:

• Brewer's yeast
• Organ meets (liver, kidney)
• Cooked eggs, especially egg yolk
• Nuts (almonds, peanuts, pecans, walnuts) and nut butters
• Soybeans
• Other legumes (beans, blackeye peas, peanuts)
• Oatbran