Definition:

Biotin-B7 is a water-soluble vitamin that is generally classified as a B-complex vitamin. After its initial discovery in 1927, 40 years of additional research was required to unequivocally establish biotin as a vitamin. Biotin is required by all organisms but can be synthesized by some strains of bacteria, yeast, mold, algae, and some plant species.

• Water-soluble biotin is an essential cofactor to enzymes in intermediary metabolism and a key regulator of gene expression.
• Both parenteral nutrition devoid of biotin and prolonged consumption of raw egg whites has been associated with symptoms of frank biotin deficiency, including hair loss, dermatitis, skin rash, ataxia, seizures, and other neurologic dysfunctions.
• Biotinidase deficiency is a rare hereditary disorder that impairs biotin absorption and recycling, resulting in secondary biotin deficiency.
• The recommended adequate intake (AI) of biotin is set at 30 micrograms (μg)/day in adults. Biotin requirements are likely increased during pregnancy and breast-feeding.
• Animal studies have shown that biotin sufficiency is essential for normal fetal development. Yet, it is not known if marginal biotin deficiency during pregnancy increases the risk for congenital anomalies in humans.
• Recent randomized controlled trials have not found high-dose biotin supplementation to be beneficial in the treatment of multiple sclerosis. Yet, results of animal studies and meta-analyses of human clinical trials are promising.
• Definitive evidence that establishes whether biotin supplementation improves glucose and lipid homeostasis in individuals with type 2 diabetes mellitus is currently lacking, but suggestive observations have been published.
• Biotin cannot be synthesized by mammalian cells and must be obtained from exogenous sources. Biotin is widely found in food, and good dietary sources include egg yolk, liver, whole-grain cereal, and some vegetables.
• Long-term anticonvulsant (anti-seizure) therapy may increase the dietary requirement for biotin because anticonvulsants can interfere with the intestinal absorption and renal re-absorption of biotin and likely also increase the degradation of biotin to inactive metabolites.

Biotin Deficiency Symptoms

Symptoms of biotin deficiency may include scaly dermatitis resembling seborrheic dermatitis, alopecia, grayish pallor, depression, lethargy, hallucinations, myalgia, hyperesthesia, paresthesias, anorexia, nausea, anemia, increased serum cholesterol, and in some cases precordial pain associated with electrocardiographic evidence of coronary ischemia. Additional manifestations of biotin deficiency in children may include conjunctivitis, ataxia, hypotonia, developmental delay, seizures, ketolactic acidosis, and organic aciduria.

Dosage and administration

• Many multivitamin products provide 30–300 μg/day of biotin. Biotin has been used in dosages of 2.5–16 mg/day to treat certain clinical conditions.
• Inborn errors of biotin metabolism have been treated in many cases with 10 mg/day, although higher doses have been used in some cases.