Serum Thiamin, Pyridoxal, Cobalamin and Folate Concentrations in Young Infants

. Blood samples were obtained from 509 apparently healthy infants between the age of 3 and 54 weeks attending for routine checks at infant health centres. Serum was assayed for thiamin, pyridoxal, cobalamin and folate. Three hundred and five infants were being breast fed and results from these were used to construct a reference range–thiamin 2-17 μg/1, pyridoxal 8-39 ng/1, cobalamin 120-800 μg/1 and folate 7-47 ng/1 (95 percentile ranges). One hundred and thirty-four infants were being fed a manufactured milk formulation and the serum concentrations of thiamin, pyridoxal and cobalamin were significantly higher than those found in breast fed infants. Thirteen infants were receiving pasteurised cow's milk. This milk was found to have more than 3 times the folate content of human breast milk yet these infants had a significantly reduced serum level of folate.