A study of 41,504 patients, who had at least one mea- sured 25-OH-D level, found the prevalence of vitamin D deficiency (?30 ng/ml) was 63.6%. Vitamin D deficiency was associated with highly significant (p <0.0001) in- crease in the prevalence of diabetes, hypertension, hyperlipidemia, and peripheral vascular disease. Also, those without CV risk factors but with severe vitamin D deficiency had an increased likelihood of developing diabetes, hypertension, and hyperlipidemia. The vitamin D levels were also highly associated with coronary artery disease, myocardial infarction, heart failure, and stroke (all p <0.0001), as well as with incident death, heart failure, coronary artery disease/myocardial infarction (all p <0.0001), stroke (p = 0.003). The authors conclude their data has “... confirmed a high prevalence of vitamin D deficiency in the general healthcare population and an association between vitamin D levels and prevalent and incident CV risk factors and outcomes. These observations lend strong support to the hypothesis that vitamin D might play a primary role in CV risk factors and disease.”1 Another study presented last August at a meeting of the Eu- ropean Society of Cardiology followed 548 patients who had been hospitalized for HF and had had their vitamin D levels checked at the time of diagno- sis. After 18 months 165 had died and 142 were hospitalized again. The researchers observed that over the next 18 months those with low levels of 25-OH-D level in their blood (<29.6nmoles/L) were 30% more likely to die or require repeat hospitalization than those with a 25-OH-D level above 43.9nmoles/L.Bottom Line: HF patients should be checked for low levels of vitamin D in their blood and those with <40nmoles/L should be given an adequate supplemental dose vitamin D3 (perhaps 2000 to 4000 IU) to attain adequate tissue levels.By James J. Kenney, PhD, RD, FACN.1. Anderson JL, et al. Am J Cardiol 2010;106:963-8