Biotin is important for the body's metabolism of protein, carbohydrates, and amino acids. It also converts glucose into blood sugar the body uses for energy. This B vitamin also plays a role in skin and hair growth, healthy bone marrow, and regeneration of nerve tissue. In pregnant women, it supplements may prevent birth defects, miscarriage, and premature birth.
Also called vitamin H, biotin serves an essential function in breaking down food at the enzyme level. It synthesizes fatty acids and regulates their oxidation. This vitamin also regulates the metabolism of cholesterol and amino acids.
A deficiency in biotin is rare, but does occur in patients who are fed intravenously if the vitamin is not included in the feeding solution. Deficiencies are also seen in people who use anti-seizure medication because it might block absorption of biotin from food. Antibiotics used over a long period of time might also lead to a deficiency because these drugs might destroy bacteria in the intestines that break down the vitamin and allow the body to absorb it.
Signs of a deficiency might include brittle nails and unexplained hair loss. Anemia, fatigue, and depression are other symptoms that may represent a lack of the vitamin. In people who suffer disorders that block absorption, impaired immune function might hinder the body's ability to fight fungal and bacterial infections.
Biotin is a water-soluble vitamin that is excreted in the urine. Tests on pregnant rats show they lose a greater amount of the vitamin through urination during pregnancy. Low levels of the vitamin caused miscarriage, birth defects, and premature birth in animal studies. The research prompted health professionals to recommend at least 30 mcg of biotin a day for pregnant women as a precaution.
Most people receive adequate amounts of biotin through diet. Egg yolks, liver, and yeast represent particularly good sources of this vitamin. It is also found in fish, nuts, legumes, and fortified cereals. The recommended daily dose of biotin is 30 mcg a day for adults, but some dietary supplements exceed this amount because there has been no scientific evidence pointing to risk of overdose.