Biotin Deficiency

In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan.


Biotin (vitamin H or vitamin B7) is a B-complex vitamin that acts as an essential coenzyme for five carboxylases: pyruvate carboxylase, 3-methylcrotonyl-CoA carboxylase, propionyl-CoA carboxylase, and coenzyme for acetyl-CoA carboxylases 1 and 2. These carboxylases help in several chemical processes in the cell, including gluconeogenesis, amino acid metabolism, and fatty acid synthesis. The Food and Nutrition Board of the Institute of Medicine recommends a daily dietary intake of 30 mcg/day to maintain good health. Biotin deficiency is very rare in those who take in a normal balanced diet. Mammals obtain biotin from food. Foods rich in biotin are egg yolk, liver, cereals (wheat, oats), vegetables (spinach, mushrooms), and rice. Dairy items and breast milk also contain biotin.

Besides, gut micro bacteria can produce biotin. The average dietary intake of biotin in the western population is approximately 35 to 70 mcg/day.

Nominal biotin deficiency has been noted in pregnant and lactating women, but its clinical significance is unknown. Biotin supplements are available in the market for improvement in nail, hair, and skin health, but there is no robust evidence available. Taking biotin supplements can interfere with some laboratory tests resulting in false-positive and false-negative results. There are studies reporting the efficacy of high-dose biotin in some neurological conditions, such as multiple sclerosis; however, the underlying mechanism is uncertain.

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