Vitamin D During Pregnancy and Infancy and Infant Serum 25-Hydroxyvitamin D Concentration
What this study found
Vitamin D3 supplementation increased maternal and infant serum 25(OH)D concentrations versus placebo, with the higher-dose arm generally achieving the highest values across time points. Maternal median 25(OH)D at 36 weeks was 39 and 41 ng/mL in the lower- and higher-dose arms versus 20 ng/mL with placebo; cord blood medians were 24 and 26 versus 13 ng/mL; and infant medians at 2 months were 34 and 43 versus 20 ng/mL. At 6 months, infant medians were 34 and 38 ng/mL versus 31 ng/mL, while the proportion reaching 25(OH)D ≥20 ng/mL was 82% and 89% versus 74%, and the proportion reaching ≥30…
- Study & population
- Randomized, double-blind trial in Auckland, New Zealand, enrolling pregnant women with singleton pregnancies at 26 to 30 weeks' gestation from a community-based primary care maternity clinic and following their healthy infants to 6 months.
- Intervention
- Oral vitamin D3 drops were given from 26 to 30 weeks' gestation until delivery for mothers and from birth to 6 months for infants.
- Key limitation
- The trial was modest in size and followed infants only to 6 months, so longer-term durability and clinical outcomes were not assessed.
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Open PDFOriginal abstract
OBJECTIVE: To determine the vitamin D dose necessary to achieve serum 25-hydroxyvitamin D (25(OH)D) concentration ≥20 ng/mL during infancy. METHODS: A randomized, double-blind, placebo-controlled trial in New Zealand. Pregnant mothers, from 27 weeks’ gestation to birth, and then their infants, from birth to age 6 months, were randomly assigned to 1 of 3 mother/infant groups: placebo/placebo, vitamin D3 1000/400 IU, or vitamin D3 2000/800 IU. Serum 25(OH)D and calcium concentrations were measured at enrollment, 36 weeks’ gestation, in cord blood, and in infants at 2, 4, and 6 months of age. RESULTS: Two-hundred-and-sixty pregnant women were randomized. At enrollment, the proportions with serum 25(OH)D ≥20 ng/mL for placebo, lower-dose, and higher-dose groups were 54%, 64%, and 55%, respectively. The proportion with 25(OH)D ≥20 ng/mL was larger in both intervention groups at 36 weeks’ gestation (50%, 91%, 89%, P < .001). In comparison with placebo, the proportion of infants with 25(OH)D ≥20 ng/mL was larger in both intervention groups to age 4 months: cord blood (22%, 72%, 71%, P < .001), 2 months (50%, 82%, 92%, P < .001), and 4 months (66%, 87%, 87%, P = .004), but only in the higher-dose group at age 6 months (74%, 82%, 89%, P = .07; higher dose versus placebo P = .03, lower dose versus placebo P = .21). CONCLUSIONS: Daily vitamin D supplementation during pregnancy and then infancy with 1000/400 IU or 2000/800 IU increases the proportion of infants with 25(OH)D ≥20 ng/mL, with the higher dose sustaining this increase for longer.