Background: Studies of the associations of circulating total 25-hydroxyvitamin D (25(OH)D) with cardiovascular disease risk factors in adults have reported inconsistent findings. We aimed to compare prospective associations of two analogues of childhood 25(OH)D (25(OH)D2 and 25(OH)D3) with cardiovascular risk factors measured in adolescence.
Methods and results: We examined associations of childhood (ages 7-12 years) 25(OH)D2 and 25-25(OH)D3 with a range of cardiovascular risk factors (blood pressure, fasting lipids, glucose, insulin and C-reactive protein (CRP)) determined in adolescence (mean age 15.4 years). Data were from 2470 participants of the Avon Longitudinal Study of Parents and Children (ALSPAC), a prospective population-based cohort. After adjustments for age, gender, socioeconomic position and BMI, there were no associations of 25(OH)D2 with cardiovascular risk factors. There was a positive association of season-adjusted (and unadjusted) 25(OH)D3 with high-density lipoprotein cholesterol (HDL-C) (mean change per doubling of 25(OH)D3: 0.03 mmol/l; 95% confidence interval (CI): 0.001 to 0.05, p = 0.02) and an inverse association with fasting insulin (relative difference of -4.59% per doubling; 95% CI: -8.37 to -0.59, p = 0.03). Participants with total 25(OH)D concentration <50 nmol/l had 0.04 mmol/l lower HDL-C (95% CI: -0.07 to -0.01) and 5.54% higher fasting insulin (95% CI: 0.82 to 10.47) compared with participants with total 25(OH)D ≥72 nmol/l.
Conclusions: In the first prospective study of children/adolescents, we have shown that higher 25(OH)D3 concentrations in childhood are associated with higher levels of HDL-C and lower fasting insulin in adolescence.
Keywords: ALSPAC; Vitamin D; cardiovascular diseases; paediatrics.