Vitamin D supplementation in obese Sri Lankan children: a randomized controlled trial

Randomized controlled trial in obese, vitamin D-deficient Sri Lankan children aged 5-15 years attending the obesity clinic at Lady Ridgway Hospital in Colombo, enrolled from October 2015 to February 2017. The active intervention arms included 32 participants in the 50,000 IU weekly group and 33 participants in the 2,500 IU weekly group.

Oral vitamin D2 (ergocalciferol) dissolved in milk was administered weekly for 24 weeks. Two active regimens were evaluated: 50,000 IU weekly and 2,500 IU weekly; both arms also received structured diet counseling and 60 min/day of physical activity.

High-dose vitamin D2 appeared to provide the most benefit, with the authors concluding that 50,000 IU weekly improved insulin function, liver-related markers, and body composition more than the lower-dose regimen. In the 50,000 IU weekly arm, vitamin D rose from 14.92 (3.04) to 18.24 (5.77), ALT fell from 39.22 (51.37) to 26.94 (14.27), PTH fell from 37.24 (18.13) to 29.23 (15.29), and percentage fat mass fell from 41.89 (4.07) to 39.76 (5.43) over 6 months. In the 2,500 IU weekly arm, vitamin D changed only slightly from 14.92 (3.92) to 15.26 (3.675), with smaller improvements in ALT, fat mass, and metabolic markers. Overall, low-dose vitamin D provided minimal additional benefit, and the authors suggested that higher-dose supplementation may enhance management in this population.

Small single-center trial with short 24-week follow-up, which limits generalizability and the ability to assess longer-term effects. Both arms also received diet and physical activity advice, so the supplement-specific contribution is not fully isolated from the lifestyle intervention. The source packet does not provide placebo-arm details or between-group statistical comparisons for the key outcomes, limiting interpretation of comparative efficacy.