Vitamin D (VitD) Supplementation of Mother and Infant vs. Mother Alone

Objective To assess safety & effectiveness of higher dose maternal vitD alone compared w/maternal & infant supplementation of 400 IU/day. Methods From 2006–2011, fully lactating women/infants at 1‐month postpartum living in Charleston, SC and Rochester, NY were randomized to 400, 2400 or. 6400 IU vitD3/d. Infants of Control mothers received 400 IU vitD3/d while infants of 2400 IU and 6400 IU grps received placebo. Results 476 mothers/infants were enrolled. No differences betw tx grps in mat/infant baseline 25(OH)D (p=0.8). 2400 IU arm was stopped in 2009: higher % infants with deficiency (25(OH)D<20 ng/mL) at 4 mos. Of remaining 2 grps, maternal 25(OH)D (ng/mL) changed from 34.0 to 30.1 in 400 IU grp (p=0.04) and from 37.2 to 59.5 in the 6400 IU grp (p<0.0001); between grp (p<0.0001). Infant 25(OH)D in the 400 IU grp increased from 17.4 to 45.2 (p<0.0001) and from 17.8 to 43.2 in the 6400 IU grp (p<0.0001); between infant grps (p=0.4). No differences in safety profiles of women and infants by tx. Conclusions Women in 6400 IU grp had improved vitD status compared to 400 IU/d grp; and their infants’ vitD status was equivalent to those infants receiving 400 IU/d. When mother is vitD sufficient, her milk is sufficient, and her BrF infant will be sufficient without further supplementation. Findings have implications re: vitD supplementation recommendations during lactation.