Metabolism of Women During the Reproductive Cycle; the Utilization of Pantothenic Acid During Lactation.

The thiamine intake for 5-day periods, secretion in 24-hour collections of milk, and daily excretion in urine were determined for normal multiparas during the first 10 days postpartum and at various intervals in mature milk production. The intakes of the mothers were comparable, qualitatively, but quantity was determined by appetite. With an average intake of 1.1 mg thiamine per day, the average daily secretion in milk increased from 1 μg on the first day to 95 μg on the tenth day and the excretion in the urine ranged from 200 μg on the first day to 145 μg on the ninth day. During the period of highest secretion of thiamine in milk, 2–3 months postpartum, thiamine in the milk averaged only 8% of the intake.