Context: Studies in adults have reported associations of low circulating total 25-hydroxyvitamin D with increased cardiovascular disease and risk factors. Evidence of associations in children, however, is limited, and it is unknown whether associations with risk factors differ for each 25-hydroxyvitamin D analog [25-hydroxyvitamin D(2) (25[OH]D(2)) and 25-hydroxyvitamin D(2) (25[OH]D(3))].
Objective: The objective of the study was to compare associations of 25(OH)D(2) and 25(OH)D(3) with cardiovascular risk factors in children.
Design/setting: The design of the study was a cross-sectional study of 4274 children (mean age 9.9 yr) from the Avon Longitudinal Study of Parents and Children.
Main outcomes: The main outcomes included blood pressure, lipids [triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C)], apolipoproteins (Apo-A1 and Apo-B), adiponectin, leptin, C-reactive protein, and IL-6.
Results: In confounder-adjusted models, 25(OH)D(2) was inversely associated with Apo-A1 (change per doubling of exposure: -0.74 mg/dl; 95% confidence interval -0.14, -0.04) and triglycerides (relative percentage change per doubling of exposure: -1.64%; -3.27, 0.01) and positively associated with C-reactive protein (8.42%; 3.40, 13.58) and IL-6 (5.75%; 1.83, 9.25). 25(OH)D(3) was positively associated with HDL-C (0.04 mmol/liter; 0.02, 0.06), Apo-A1 (1.96 mg/dl; 0.65, 3.24), and adiponectin (0.47 μg/ml; 0.15, 0.79). There was statistical evidence that associations of 25(OH)D(2) and 25(OH)D(3) with HDL-C, Apo-A1, and IL-6 differed from each other (all P values for differences ≤0.02).
Conclusions: Higher circulating 25(OH)D(3) was associated with cardioprotective levels of HDL-C, Apo-A1, and adiponectin in children. Associations of 25(OH)D(2) with cardiovascular risk factors were in mixed directions. It is necessary to see whether these associations are replicated in large prospective studies.