Vitamin D, tuberculin skin test conversion, and latent tuberculosis in Mongolian school-age children: a randomized, double-blind, placebo-controlled feasibility trial1,2,3
Am J Clin Nutr August 2012 ajcn.034967
Davaasambuu Ganmaa, Edward Giovannucci, Barry R Bloom, Wafaie Fawzi, Winthrop Burr, Dulguun Batbaatar, Nyamjav Sumberzul, Michael F Holick, and Walter C Willett
1 From the Department of Nutrition, Harvard School of Public Health and Channing Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, MA (DG, EG, and WCW); the Health Sciences University of Mongolia, Ulaanbaatar, Mongolia (DG, WB, DB, and NS); the Department of Immunology and Infectious Diseases and Department of Global Health and Population, Harvard School of Public Health, Boston, MA (BRB); Harvard University Health Services, Cambridge, MA (WB); the Department of Nutrition, Epidemiology and Global Health and Population, Harvard School of Public Health, Boston, MA (WF); and the Endocrine, Diabetes and Nutrition Section, Department of Medicine, Boston University Medical Center, Boston, MA (MFH).
2 Supported by NIH/NHLBI 5 K99 HL089710-02 and 4 R00 HL089710-03. The Tischon Corporation of Salisbury, MD, donated the vitamin D supplements.
?3 Address correspondence to D Ganmaa, 665 Huntington Avenue, Building II, Room 341B, Harvard School of Public Health and Channing Laboratory, Boston, MA. E-mail: gdavaasa at hsph.harvard.edu.
Background: By modulating immune function, vitamin D might increase innate immunity and inhibit the growth of initial bacterial invasion and protect against tuberculosis infection.
Objective: We examined the effect of vitamin D supplementation on tuberculin skin test (TST) conversion.
Design: A double-blind, placebo-controlled study was conducted in 120 Mongol schoolchildren. We estimated the prevalence of latent tuberculosis infection at baseline and examined the effect of vitamin D (800 IU/d) on serum concentrations of 25-hydroxyvitamin D [25(OH)D] and TST conversion.
Results: At baseline, the mean (±SD) 25(OH)D concentration was 7 ± 4 ng/mL, and all concentrations were <20 ng/mL.
Vitamin D supplementation increased serum 25(OH)D by a mean of 12.7 ng/mL compared with placebo (P < 0.0001).
At baseline, 16 children in the vitamin D group and 18 in the placebo group were TST positive (P = 0.7).
Over 6 mo, TSTs converted to positive in 5 (11%) children receiving vitamin D compared with 11 (27%) receiving placebo (RR: 0.41; 95% CI: 0.16, 1.09; P = 0.06).
Only one TST conversion occurred among those whose serum 25(OH)D concentration increased to >20 ng/mL,
whereas 8 TST conversions occurred in those whose final 25(OH)D concentration remained <10 ng/mL (P = 0.05).
The mean increase in stature was 2.9 ± 1.6 cm in the vitamin D group and 2.0 ± 1.7 cm in the placebo group (95% CI: 2.16, 2.81; P < 0.003).
Conclusions: Vitamin D supplementation for 6 mo had significant favorable effects on serum 25(OH)D concentrations and on growth in stature.
A trend was seen toward fewer TST conversions in the vitamin D group.
This trial was registered at clinicaltrials.gov as NCT01244204.
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27% of controls got TB, and grew 2 cm
11% of those getting 800 IU of vitamin D got TB and grew 2.9 cm
2.5X less chance of TB than controls and grew in height 50% more than controls