Vitamin D Supplementation in Breastfeeding Women

Adequate vitamin D is essential for proper infant growth and development. However, human milk is low in vitamin D, and most infants do not receive recommended supplementation. Our aim is to assess the feasibility of providing adequate vitamin D to breastfed infants through maternal vitamin D supplementation. Forty non-pregnant, lactating women at least 18 years of age with exclusively breastfed infants between the ages of 1 and 6 months will be randomized to receive oral vitamin D as either 5,000 IU daily for 28 days or 150,000 IU as a single dose. Maternal serum calcium, phosphorus, vitamin D and 25(OH)D; maternal urinary calcium; maternal milk vitamin D and 25(OH)D will be measured on days 0, 1, 3, 7, 14, and 28 of the study; and infant serum vitamin D and 25(OH)D will be measured on days 0 and 28.