Weekly Vitamin D Supplementation to Prevent Acute Respiratory Infections in Young Children at Different Latitudes: A Randomized Controlled Trial

source extracted confidence: high 2026-04-09
#humans #female #male #respiratory-tract-infections #double-blind-method

Weekly Vitamin D Supplementation to Prevent Acute Respiratory Infections in Young Children at Different Latitudes: A Randomized Controlled Trial

Reyes et al., 2024 | J Pediatr | Rct

Citation

Reyes María Loreto, Vizcaya Cecilia, ... Borzutzky Arturo. Weekly Vitamin D Supplementation to Prevent Acute Respiratory Infections in Young Children at Different Latitudes: A Randomized Controlled Trial. J Pediatr. 2024-Dec;275:114249. doi:10.1016/j.jpeds.2024.114249

Abstract

OBJECTIVE: To evaluate the effectiveness of weekly vitamin D supplementation in reducing the number of acute respiratory infections (ARI) in preschool children. STUDY DESIGN: Randomized, double-blind, placebo-controlled trial in 303 children aged 1.5-3.5 years from 2014 to 2105 in 3 Chilean cities at different latitudes: Santiago (33°S, n = 101), Talcahuano (37°S, n = 103), and Punta Arenas (53°S, n = 99). Participants were allocated (1:1:1) to receive placebo, cholecalciferol (vitamin D3 (VD3)) 5600 IU/week (low-dose), or 11 200 IU/week (high-dose) for 6 months. Primary outcome was parent-reported number of ARI; secondary outcomes included number of ARI hospitalizations, change of serum 25-hydroxyvitamin D (25(OH)D) and LL-37/cathelicidin levels, and adverse events. RESULTS: The mean age of participants was 26 ± 6 months; 45% were female. Baseline 25(OH)D was 24.9 ± 6.1 ng/ml, with 23% having 25(OH)D <20 ng/ml. No significant baseline clinical or laboratory differences were observed among groups. Overall, 64% (n = 194) completed study participation, without baseline differences between subjects lost to follow-up vs those completing participation or differences in completion rates across groups. After 6 months, a dose-dependent increase in serum 25(OH)D was observed from the VD3 intervention (P < .001), with a higher proportion of subjects ending the trial with 25(OH)D <20 ng/ml in the placebo group (30.8%) vs the low-dose (7.4%) and high-dose groups (5.1%). However, no group differences were observed in number of ARI (P = .85), ARI hospitalizations (P = .20), LL-37/cathelicidin change (P = .30), or adverse events (P = .41). CONCLUSIONS: While weekly VD3 supplementation, in doses equivalent to 800 IU and 1600 IU daily, was associated with improved 25(OH)D levels in preschoolers, we did not find a reduced number of ARI in this sample.

Key Findings

The mean age of participants was 26 ± 6 months; 45% were female. Baseline 25(OH)D was 24.9 ± 6.1 ng/ml, with 23% having 25(OH)D <20 ng/ml. No significant baseline clinical or laboratory differences were observed among groups. Overall, 64% (n = 194) completed study participation, without baseline differences between subjects lost to follow-up vs those completing participation or differences in completion rates across groups. After 6 months, a dose-dependent increase in serum 25(OH)D was observed

Outcomes Measured

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Population

Field Value
Population See abstract
Sample Size 101
Age Range See abstract
Condition See abstract

MeSH Terms

  • Humans
  • Female
  • Male
  • Respiratory Tract Infections
  • Double-Blind Method
  • Child, Preschool
  • Dietary Supplements
  • Vitamin D
  • Infant
  • Cholecalciferol
  • Acute Disease
  • Vitamins
  • Chile
  • Vitamin D Deficiency

Evidence Classification

  • Level: Rct
  • Publication Types: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't
  • Vertical: vitamin-d-immune

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09