Vitamin D and cardiovascular disease.

Vitamin D participates in numerous physiologic and pathologic processes. Most tissues have vitamin D receptors (VDRs), and vitamin D is an important regulator of gene expression. Approximately 1 billion people worldwide have insufficient levels of vitamin D. Deficiency has been associated with many chronic diseases, including cardiovascular disease (CVD), which is the leading cause of death in both men and women. A relationship between vitamin D and CVD is implicated; however studies show conflicting data. Epidemiologic evidence and observational studies demonstrate an association between vitamin D deficiency and CVD; however, this is not substantiated by randomized controlled trials (RCTs). Many questions remain unanswered, but growing evidence supports a beneficial role of vitamin D on cardiovascular health. Key teaching points: • Vitamin D influences many cellular functions. • A global pandemic of vitamin D deficiency exists. • Epidemiologic data and observational studies suggest that vitamin D deficiency may increase cardiovascular risk. • RCTs show no significant relationship (however, studies have significant limitations). • The association between vitamin D status and CVD is uncertain, but low vitamin D levels may be an independent and modifiable CV risk factor.