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.