Vitamin D insufficiency may be associated with increased risk of coronary heart disease (CHD) and cardiovascular disease (CVD) in general, but uncertainties exist beyond published reports. The Vitamin D Studies Collaboration (VitDSC) is a CEU-led consortium that is assessing in detail the associations of 25-hydroxyvitamin D [25(OH)D], the principal clinical biomarker of vitamin D status, with cardiovascular disease outcomes and cause-specific mortality by meta-analysis of individual participant data (IPD) from 106,900 participants in 34 prospective cohort studies. The specific aims are:
- To assess correlates of 25(OH)D levels and the shape of dose-response relationships between 25(OH)D and cardiovascular disease outcomes and cause-specific mortality.
- To consistently adjust for confounding factors (e.g. season, age, sex, obesity, smoking, ethnicity, physical activity, etc) in assessing the above associations.
- To correct associations for impact of regression dilution in both 25(OH)D levels and in the confounders.
- To evaluate whether the association of 25(OH)D and outcomes importantly differ by clinically relevant subgroups (e.g. age, sex, smoking, diabetes, obesity, ethnicity, and other established risk factors) and methods of assessment.
- To assess the incremental predictive value of 25(OH)D for cardiovascular disease risk prediction beyond conventional CVD risk factors.
- To assess the causal relevance of 25(OH)D in cardiovascular disease and other major disease outcomes using Mendelian randomisation.