The effect of thiamin and riboflavin supplementation on the level of those vitamins in human breast milk and urine.

Thiamin and riboflavin concentrations in urine and breast milk were measured to see if vitamin supplementation during lactation is beneficial to healthy well-nourished women. seven supplemented subjects and five nonsupplemented subjects expressed milk four times per day for 3 days at 1 and 6 weeks postpartum. Dietary intakes were recorded for 1 day before milk collection and the 3 days of milk collection. A 24-hr urine sample was collected at 1 and 6 weeks postpartum. Mean thiamin concentration in the milk increased significantly in both groups between 1 and 6 weeks postpartum, although there were no significant differences between groups. Riboflavin values reflected in the milk were significantly lower in the nonsupplemented group of women both at 1 and 6 weeks postpartum, but values did not change significantly in either groups as the milk matured from 1 to 6 weeks postpartum. Urinary excretion of thiamin and riboflavin was proportionally higher in the supplemented group of women. Riboflavin and thiamin status of both groups of women depicted normal intakes and the milk concentration of thiamin and riboflavin either met or exceeded established norms in both groups of women.