Low serum biotin levels in Japanese children fed with hydrolysate formulas.

Background: Given that nutritional biotin deficiency in Japanese infants has been reported, a straightforward method for estimating biotin level is needed. The biotin content in infant formula, breast milk, and the sera of infants fed with various types of formula were measured using avidin-binding assay. Methods: A commercially available ELISA kit was used for the measurement of biotin in 54 types of formula, including hydrolysate formulas for milk allergy, as well as in breast milk and in the sera of 27 infants fed with these formulas. Results: The biotin content reached the recommended value in only five formulas. All of the hydrolysate formulas and more than half of the special formulas contained biotin <0.1 mu g/dL. Serum biotin was low in infants fed only with the hydrolysate formulas, and one of them had alopecia related to biotin deficiency. Conclusion: While many were asymptomatic, infants fed with formulas lacking biotin are at risk of developing symptomatic disease. The addition of biotin to breast milk substitutes was finally approved in the middle of 2014, however pediatricians in Japan should still be vigilant with regard to nutritional biotin deficiency in infants for the time being.