748 - What is the expected improvement in vitamin D status for children that occurs with supplementation? A systematic review and meta-analysis

Publication Number: 748.7025

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: Vitamin D supplementation is recommended for children. What is the expected increase in serum 25-hydroxyvitamin D [25(OH)D] concentration that occurs with vitamin D supplementation during early childhood?

Objective: To conduct a Cochrane Systematic Review to quantify the change in serum 25(OH)D concentration that occurs in children up to 5 years of age supplemented with vitamin D.

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Embase, CINAHL, EBSCO, Web of Science, Global Index Medicus, Register of Controlled Trials platforms and sources of unpublished data from inception to July 2023.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 children and 25(OH)D concentration was measured in the children’s serum at end of treatment.

Results: From 5434 records screened, we included 107 studies (n=31,521) in the review, with 40 (n= 5352) studies reporting on serum 25(OH)D concentrations in children when the intervention was given anytime from birth up to 5 years of age. Twenty-five studies compared vitamin D versus placebo, and fifteen compared higher versus lower dose vitamin D. Included randomized controlled trials were published between 1981 to 2023, reporting data from all World Health Organization global regions. When given daily, dosages ranged from ≈ 285 to 3000 IU/daily. Bolus doses ranged from 50,000 to 300,000 IU. Treatment duration varied from 4 days to 24 months.
In the vitamin D versus placebo studies, the mean difference (MD) in children’s 25(OH)D concentration was 29.17 nmol/L [95% confidence interval (CI) 27.37 – 30.98 nmol/L], 25 studies, n=2706, I²=97%, favoring the vitamin D group. In ng/mL, the MD (95% CI) was 11.66 ng/mL (10.94 – 12.39 ng/mL).
In the higher versus lower dose studies, the MD in children’s 25(OH)D concentration was 28.61 nmol/L (95% CI 26.43 – 30.79), 15 studies, n=2646, I²=92%, favoring the higher dose group. In ng/mL, the MD (95% CI) was 11.44 ng/mL (10.57 – 12.31 ng/mL).

Conclusion(s): Vitamin D supplementation during early childhood increases serum 25(OH)D concentration by at least 29 nmol/L (11.6 ng/mL) in comparison to placebo and by at least 28 nmol/L (11.4 ng/ml) when a higher dose is compared to a lower dose of vitamin D.