Serum 25-hydroxyvitamin D, cardiovascular risk markers, and incident cardiovascular disease in a high risk community population

Background: It is unclear whether vitamin D status is related to cardiovascular risk beyond that explained by conventional risk markers. We examined the relationship between serum 25-hydroxy (OH) vitamin D and incident cardiovascular disease (CVD; heart attack/stroke) after adjusting for individual- and community-level covariates from laboratory, administrative and survey data. Methods: Patients receiving their first 25-OH vitamin D test in Calgary, Alberta from 2009 to 2013 without a past CVD diagnosis but an electrocardiogram and body mass index (BMI) +/- 3 months from testing were included. The following was merged to this data: first results for laboratory-measured CVD risk markers (lipid profile, fasting plasma glucose, and HbA1c) measured +/- 3 months from testing; Census Dissemination Area (CDA)level indicators of socioeconomic status (SES) in 2011; and CVD diagnoses > 3 months from testing between 2009 and 2016. Linear and Poisson regression were used to examine associations between 25-OH vitamin D quartile and covariates, and Cox proportional hazard models were used to examine associations with incident CVD before and after adjusting for covariates. Results: Among 72 348 patients, there were 1898 CVD events over a median of 6.0 years. Increasing quartile of 25-OH vitamin D was associated with improved lipid and glycemic profiles (p < 0.01), higher proportion of CDAlevel indicators of high SES (p < 0.01), and a lower risk of CVD (Q4 vs Q1: HR: 0.72, 95% CI: 0.63-0.81, p for trend < 0.01) after adjusting for age, sex and average daily hours of sunlight during month of testing. The association with CVD was unchanged after adjusting for BMI, slightly attenuated after adjusting for SES but completely abolished after adjusting for laboratory-measured cardiovascular risk markers. Conclusions: Vitamin D status likely offers no additional information on CVD risk over conventional laboratorymeasured risk markers.

Automated summary

The study found that higher levels of 25-hydroxy vitamin D were associated with improved lipid and glycemic profiles as well as a lower risk of cardiovascular disease. However, the influence of vitamin D status on cardiovascular disease risk disappeared after adjusting for other factors.