Vitamin D Deficiency: A Potential Modifiable Risk Factor for Cardiovascular Disease in Children with Severe Obesity.

Severe obesity is associated with abnormal lipids and increased risk for cardiovascular disease. Obesity is a risk factor for vitamin D deficiency. We examined relationship between 25-hydroxy vitamin D (25(OH)D) concentrations and lipids in children with severe obesity. Medical records of 376 children were reviewed. Linear regression models and logistic regression were used to examine the relationship between 25(OH)D and lipids after adjustment for age, gender, season of blood draw, body mass index (BMI) z-score, and BMI % of 95th percentile. Two-hundred sixty-three out of 376 children (70%) had 25(OH)D concentrations < 30 ng/mL. Concentrations of 25(OH)D were positively correlated with those of high-density lipoprotein cholesterol (HDL-C) (r² = 0.08, r = 0.22, β = 0.16, 95% CI = 0.05-0.27, p = 0.004). HDL-C was lower in children with 25(OH)D < 30 ng/mL (n = 263) compared to those with 25(OH)D ≥ 30 ng/mL (n = 113) (41.3 ± 10.2 vs. 46.4 ± 12 mg/dL, p < 0.0001). Children with 25(OH)D concentrations < 30 ng/mL had greater adjusted odds of low HDL-C (<40 mg/dL) compared with those with 25(OH)D ≥ 30 ng/mL (47.9% vs. 29.2%, OR 2.15 (1.33-3.51), p = 0.0019). Total cholesterol and non-HDL-C were not correlated with 25(OH)D concentrations. Vitamin D deficiency is highly prevalent in children with severe obesity. Prospective clinical trials are warranted to determine if vitamin D supplementation can improve HDL-C and potentially decrease risk for cardiovascular disease in children with obesity.