Efficacy of Daily Supplementation of Milk Fortified With Vitamin D2 for Three Months in Healthy School Children: A Randomized Placebo Controlled Trial

Objective To evaluate the efficacy of daily supplementation of 200 mL milk fortified with 240 IU of vitamin D2 (ergocalciferol). Design Double-blind randomized controlled trial. Settings School-based study in Delhi between October and December, 2019. Participants 235 healthy children aged 10–14 years. Intervention Daily supplementation of 200 mL milk fortified with 240 IU of ergocalciferol in intervention group ( n =119) and 200 mL of plain milk in control group ( n =116) for 3 months. Outcome Measures Change in serum 25 hydroxy vitamin D (25(OH)D), parathyroid hormone (PTH), bone formation and resorption markers, and urinary calcium creatinine ratio (U-Ca/CrR). Results The mean (SD) baseline serum 25(OH) D level in control and fortification groups was 11.9 (3.8) and 11.4 (3.6) ng/mL ( P =0.23), respectively. The serum 25(OH)D levels did not increase post-intervention with the dose used for fortification, but were significantly higher in intervention group as compared to control group [10.8 (3.4) vs 6.7 (3.5) ng/mL; P <0.001]. A higher proportion of secondary hyperparathyroidism was observed post-intervention in control (39%) than in intervention group (13.3%); P <0.001. Serum carboxy-terminal telopeptide levels were similar in both groups but the serum procollagen type1 N-terminal propeptide levels were higher in the control than intervention group ( P <0.007), following supplementation. Conclusion Supplementation of milk fortified with approximately 240 IU vitamin D2 for three months did not achieve sufficient serum 25(OH)D levels in Indian children with vitamin D deficiency during winter.