Vitamin B7, also known as biotin, vitamin H or vitamin B8, is a water-soluble vitamin, required by all organisms and is classified as a B-complex vitamin. There are eight different stereoisomers of biotin, but only one of them, D-biotin, occurs naturally and has full vitamin activity (essential cofactor for carboxylases in the intermediary metabolism) . Biotin can only be synthesized by some strains of
bacteria, mould, yeast, algae, and by certain plant species.
Vitamin B7 (biotin) contributes to the maintenance of normal skin, hair and mucous membranes, the nervous system, and psychological functions. The European Food Safety Authority (EFSA), which provides scientific advice to assist policy makers, has confirmed that clear health benefits have been established for the dietary intake of biotin in contributing to: normal macronutrient metabolism; normal energy yielding metabolism; the maintenance of normal skin and mucous membranes; the normal function of the nervous system; the maintenance of normal hair; normal psychological functions.
Research indicates that at least one-third of women develop marginal vitamin B7 (biotin) deficiency during the course of pregnancy. However, it is still unknown whether this decline in biotin nutritional status might elevate the risk of congenital anomalies. Although the level of biotin depletion is not severe enough to cause diagnostic signs or symptoms, such observations are sources of concern because biotin deficiency without clinical signs or symptoms has been shown to cause birth defects such as cleft palate and limb hypoplasia in several animal species.
The potential risk for abnormal development of the embryo or foetus from biotin deficiency (impaired carboxylase activity) makes it prudent to ensure adequate biotin intake throughout pregnancy. Since pregnant women are advised to consume supplemental vitamin B9 (folic acid) prior to and during pregnancy to prevent neural tube defects, it would be easy to consume supplemental biotin (at least 30 mcg/day) in the form of a multivitamin that also contains at least 400 mcg folic acid. Toxicity at this level of biotin intake has never been reported.