Low 25(OH)D3 levels are associated with total adiposity, metabolic syndrome, and hypertension in Caucasian children and adolescents.

Objectives: Evidence of the association between vitamin D and cardiovascular (CV) risk factors in the young is limited. We therefore assessed the relationships between circulating 25-hydroxyvitamin D3 [25(OH)D3] and metabolic syndrome (MetS), its components, and early atherosclerotic changes in 452 (304 overweight/obese, 148 healthy, normal weight) Caucasian children. Methods: We determined serum 25(OH)D3 concentrations in relation to MetS, its components [central obesity, hypertension, low HDL cholesterol, hypertriglyceridemia, glucose impairment and/or insulin resistance], as well as to impairment of flow-mediated vasodilatation (FMD) and increased carotid intima-media thickness (cIMT) - two markers of subclinical atherosclerosis. Results: Higher 25(OH)D3 was significantly associated with a reduced presence of MetS. Obesity, central obesity, hypertension, hypertriglyceridemia, low HDL cholesterol, IR, and MetS were all associated with an increased odds of having low 25(OH)D3 levels, after adjustment for age, sex, and Tanner stage. After additional adjustment for SD score (SDS)-BMI, elevated blood pressure and MetS remained significantly associated with low vitamin D status. The adjusted odds ratio (95% confidence interval) for those in the lowest (< 17 ng/mL) compared with the highest tertile (> 27 ng/mL) of 25(OH)D3 for hypertension was 1.72 (1.02-2.92), and for MetS it was 2.30 (1.20-4.40). A similar pattern of association among 25(OH)D3, high blood pressure and MetS was observed when models were adjusted for waist circumference. No correlation was found between 25(OH)D3 concentrations and either FMD or cIMT. Conclusions: Low 25(OH)D3 levels in Caucasian children are inversely related to total adiposity, MetS and hypertension.