Hollis BW, Wagner CL, Howard CR, et al. Maternal Versus Infant Vitamin D Supplementation During Lactation: A Randomized Controlled Trial. Pediatrics. 2015, 136:625-34.

Reference [16]

Randomized Controlled Trial


95 exclusively/ fully breastfeeding mother/infant pairs in Charleston, South Carolina and Rochester, New York

Group 1: Maternal supplement 400 IU vitamin D3 per day; 400 IU vitamin D3 per day for infants

Group 2: Maternal supplement 2400 IU vitamin D3; placebo for infants (discontinued due to safety concerns, not included in analysis)

Group 3: Maternal supplement 6400 IU vitamin D3; placebo for infants

Maternal 25(OH)D levels were significantly higher in mothers supplemented with 6400 IU than those with 400 IU at visits 4 and 7 (p < 0.001; p < 0.001, respectively). Infant 25(OH)D was similar between groups at all visits (p = 0.35 at V1, p = 0.10 at V4, and p = 0.94 at V7). Maternal supplementation with 6400 IU/day is as effective at meeting infant vitamin D needs as directly supplementing the infant 400 IU/day

Basile LA, Taylor SN, Wagner CL, Horst RL, Hollis BW. The effect of high-dose vitamin D supplementation on serum vitamin D levels and milk calcium concentration in lactating women and their infants. Breastfeed Med. 2006, 1:27-35. Reference [3]

Randomized Controlled Trial


25 fully breastfeeding mother-infant pairs in South Carolina

Group 1: Maternal supplement 400 IU vitamin D3 + 1600 IU vitamin D2

Group 2: Maternal supplement 400 IU vitamin D3 + 3600 IU vitamin D2

Women in both study groups had significantly elevated circulating 25(OH)D concentrations after the 3 months of supplementation (2000 IU group: p = 0.002; 4000 IU group: p = 0.0008). Women receiving 4000 IU/day exhibited significantly higher 25(OH)D concentrations than those in the 2000 IU/day group (p = 0.03). Infants experienced a significant increase in 25(OH)D. Infants in the 4000 IU group exhibited a higher 25(OH)D concentration compared to 2000 IU (p = 0.01).

Wagner CL, Hulsey TC, Fanning D, Ebeling M, Hollis BW. High-dose vitamin D3 supplementation in a cohort of breastfeeding mothers and their infants: a 6-month follow-up pilot study. Breastfeed Med. 2006.1:59-70.

Reference [11]

Randomized Controlled Trial


10 fully lactating mother-infant pairs in South Carolina (of note, only 4 continued breastfeeding through the entire study, but intent-to-treat included all 10 women)

Group 1: Maternal supplement 400 IU vitamin D3/day; 300 IU/day vitamin D3 for infants

Group 2: Maternal supplement 6400 IU vitamin D3/day; placebo for infants

The total circulating 25(OH)D levels of mothers in group 1 decreased through visit 5; there was a slight improvement at visits 6 and 7 that corresponded to increased outdoor activities and sun exposure (significance not provided). Mothers in group 2 had an immediate increase in 25(OH)D levels that was sustained throughout the study period (significance not provided). Despite the increased outdoor activities and an increase in sunlight exposure that paralleled group 1, after achieving steady-state by month 3, there was very little change in maternal 25(OH)D from months 3 to 7. Compared to group 1, the mean milk ARA in group 2 significantly increased to 873 IU/L (p < 0.0003), which resulted in a dramatic rise in infant circulating 25(OH)D levels. This rise in infant 25(OH)D was almost identical to that in the infants receiving 300 IU/day vitamin D3 directly via oral supplementation.

Oberhelman SS, Meekins ME, Fischer PR, et al. Maternal vitamin D supplementation to improve the vitamin D status of breastfed infants: a randomized controlled trial. Mayo Clin Proc. 2013,

Randomized Controlled Trial


40 exclusively breastfeeding mother-infant pairs in Rochester, Minnesota

Group 1: Maternal supplement 150,000 IU vitamin D3 monthly

Group 2: Maternal supplement 5000 IU vitamin D3/day

The single dose group had significantly greater maternal 25(OH)D concentrations than the daily dose group on days 1, 3, and 7, but not on days 14 and 28. In the single dose group, maternal 25(OH)D values peaked on day 3, and the maximum value observed in any mother was 72 ng/mL. By day 28 the increase in 25(OH)D between baseline and day 28 was 11.9 +/− 4.2 ng/mL in the single dose group and 15.0 +/− 5.7 ng/mL in the daily dose group (p = 0.06). None of the mothers’ serum 25(OH)D concentration remained < 20 ng/mL