Folate contents in human milk and casein-based and soya-based formulas, and folate status in Korean infants.

We assessed folate nutritional status from birth to 12 months in fifty-one infants who were fed human milk (HM; n 20), casein-based formula (CBF; n 12) or soya-based formula (SBF; n 19). Folate contents in ninety-five HM samples obtained from twenty mothers for the first 6-month period and twelve CBF and nineteen SBF samples were measured by bioassay after trienzyme extraction. Folate intake was estimated by weighing infants before and after feeding in the HM group and by collecting formula intake records in the formula-fed groups. After solid foods were introduced, all foods consumed were included to estimate folate intake. Serum folate and total homocysteine (tHcy) concentrations were determined at 5 and 12 months of age, and infant growth was monitored for the first 12 months. Mean HM folate contents ranged from 201 to 365 nmol/l with an overall mean of 291 nmol/l, and the contents peaked at 2 months postpartum. HM folate contents were higher than those reported in North America. Folate contents in CBF and SBF were markedly higher than those in HM and those claimed on the product labels. The overall folate intakes in formula-fed infants were significantly higher than those in HM-fed infants, and this was associated with significantly higher folate and lower tHcy in formula-fed infants than HM-fed infants at 5 months. At 12 months, serum folate was significantly higher in the SBF group than the other groups, whereas serum tHcy and overall growth were similar among all groups.