Randomized trial of vitamin D supplementation and risk of acute respiratory infection in Mongolia.

Abstract

OBJECTIVE:

Observational studies suggest that serum levels of 25-hydroxyvitamin D (25[OH]D) are inversely associated with acute respiratory infections (ARIs). We hypothesized that vitamin D supplementation of children with vitamin D deficiency would lower the risk of ARIs.

METHODS:

By using cluster randomization, classrooms of 744 Mongolian schoolchildren were randomly assigned to different treatments in winter (January-March). This analysis focused on a subset of 247 children who were assigned to daily ingestion of unfortified regular milk (control; n = 104) or milk fortified with 300 IU of vitamin D(3) (n = 143). This comparison was double-blinded. The primary outcome was the number of parent-reported ARIs over the past 3 months.

RESULTS:

At baseline, the median serum 25(OH)D level was 7 ng/mL (interquartile range: 5-10 ng/mL). At the end of the trial, follow-up was 99% (n = 244), and the median 25(OH)D levels of children in the control versus vitamin D groups was significantly different (7 vs 19 ng/mL; P < .001). Compared with controls, children receiving vitamin D reported significantly fewer ARIs during the study period (mean: 0.80 vs 0.45; P = .047), with a rate ratio of 0.52 (95% confidence interval: 0.31-0.89). Adjusting for age, gender, and history of wheezing, vitamin D continued to halve the risk of ARI (rate ratio: 0.50 [95% confidence interval: 0.28-0.88]). Similar results were found among children either below or above the median 25(OH)D level at baseline (rate ratio: 0.41 vs 0.57; P(interaction) = .27).

CONCLUSIONS:

Vitamin D supplementation significantly reduced the risk of ARIs in winter among Mongolian children with vitamin D deficiency.

• Authors: Carlos A Camargo Jr, Davaasambuu Ganmaa, A Lindsay Frazier, Franca F Kirchberg, Jennifer J Stuart, Ken Kleinman, Nyamjav Sumberzul, Janet W Rich-Edwards
• Journal: Pediatrics (Pediatrics) Vol. 130 Issue 3 Pg. e561-7 (Sep 2012) ISSN: 1098-4275 [Electronic] United States
• PMID: 22908115 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Vitamin D
• 25-hydroxyvitamin D

Topics

• Acute Disease
• Animals
• Child
• Dietary Supplements
• Double-Blind Method
• Food, Fortified
• Humans
• Milk
• Mongolia
• Respiratory Tract Infections (blood, prevention & control)
• Vitamin D (administration & dosage, analogs & derivatives, blood)
• Vitamin D Deficiency (complications, therapy)