In the last 3 years, more evidence accumulated that vitamin D (vitD)deficiency associates with cardiovascular disease (CVD) and risk factors. The association with higher cardiovascular (CV) mortality was stronger than with nonfatal CVD events. A higher incidence of type 2 diabetes was also shown. Many factors related to lifestyle (physical activity in particular) influence both vitD levels and CVD, and may contribute to explain these observational data. Whether the association between vitD and CVD is causal can only be established through randomized controlled trials (RCTs), and to date the results of the randomized trials, which were not designed for investigating CV outcomes, do not support the association data. Answers on the effects of vitD supplementation on primary and secondary prevention of CV may be found in the specifically designed ongoing RCTs. In the mean time, low vitamin D levels should be regarded as a marker of unhealthy lifestyle, requiring a more aggressive attempt at modifying individual lifestyle.