743 - Should mothers be supplemented vitamin D for their children? A systematic review and meta-analysis

Publication Number: 743.6587

Marisa van Arragon, University of Auckland, Auckland, Auckland, New Zealand; Cameron C. Grant, University of Auckland, Auckland, Auckland, New Zealand; Robert K. Scragg, School of Population Health, University of Auckland, Auckland, Auckland, New Zealand; Vanessa Jordan, University Of Auckland, Auckland, Auckland, New Zealand

Background: Newborn vitamin D status is determined by maternal vitamin D status during pregnancy. The half-life of 25-hydroxyvitamin D [25(OH)D] is 2-3 weeks. Therefore, to lower the risk of disease caused by vitamin D deficiency during infancy requires vitamin D supplementation to begin during pregnancy.

Objective: To conduct a Cochrane Systematic Review to report newborn serum 25(OH)D levels resulting from vitamin D supplementation given during pregnancy.

Design/Methods: The protocol for this review has been published (DOI: 10.1002/14651858.CD015111). We searched CENTRAL, PubMed, Embase, CINAHL, EBSCO, Web of Science, Global Index Medicus, Register of Controlled Trials platforms and sources of unpublished data from inception to July 2023. Included randomized controlled trials compared vitamin D versus placebo or higher dose (≥1000 IU) versus lower dose (≤1000 IU) vitamin D supplementation, given from early pregnancy up to age 5 years. For this objective we included studies where the intervention was given to pregnant women and the outcome was measured in the newborn child from a cord blood sample or collected at birth up to 6 weeks postpartum.

Results: From 5434 records screened, we included 107 studies (n=31,521), with 24 (n=3696) reporting newborn serum 25(OH)D levels when the intervention was given during pregnancy. Nine studies compared vitamin D versus placebo and 15 studies compared higher versus lower dose vitamin D. The included randomized controlled trials were published from 1980-2024, reporting data from all World Health Organization global regions. Interventions were given during any pregnancy trimester, with different durations and dosages.
In the vitamin D versus placebo studies, the mean difference (MD) in newborn 25(OH)D concentration was 43.19 nmol/L [95% confidence interval (CI) 41.06 - 45.33 nmol/L], nine studies, n=1144, I²=96%) favoring the vitamin D group. In ng/mL, the MD (95% CI) was 17.27 ng/mL (16.42 - 18.13 ng/mL).
In the higher versus lower dose studies, the MD in newborn 25(OH)D concentration was 25.05 nmol/L (95% CI 24.05 - 26.04 nmol/L), 15 studies, n=2552, I²=97%) favoring the higher dose group. In ng/mL the MD (95% CI) was 10.02 ng/mL (9.62 - 10.41 ng/mL).

Conclusion(s): The increases that occur in newborn serum 25(OH)D concentration with vitamin D supplementation compared to placebo during pregnancy are statistically and clinically significant. Vitamin D supplementation during pregnancy at doses equivalent to ≥1000 IU/daily result in statistically and clinically significant higher newborn serum 25(OH)D concentrations compared to vitamin D supplementation doses of ≤1000 IU/daily.