Response to single oral dose vitamin D in obese vs non-obese vitamin D–deficient children

Obese individuals are prone to vitamin D deficiency because of sequestration of vitamin D in their body fat. We planned to evaluate the rise in serum 25(OH)D levels in vitamin D–deficient obese vs normal body mass index(BMI) children, after administration of identical single dose of vitamin D. Twenty-two obese and 22 normal BMI children with serum 25 (OH)D < 20 ng/mL were given single oral dose 150,000 IU vitamin D, and 25 (OH)D levels were measured at 1 week and 1 month post-intervention. Results show that rise in 25(OH)D level from baseline was about 2.2 times lesser in obese compared with children with normal BMI, both at 1 week and at 1 month. The rise in 25(OH)D from baseline to 1 month was inversely correlated to BMI (r = − 0.56, p = < 0.001), waist circumference (r = − 0.48, p = 0.001), total fat mass (r = − 0.58, p < 0.001), and fat mass index (r = − 0.59, p < 0.001).

Conclusion: The obese children have a 2.2 times lower rise in serum vitamin D levels as compared with the normal BMI children for the same dose of vitamin D supplementation.