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.
Conclusions: 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.