Vitamin D status and incident cardiovascular disease and all-cause mortality: a general population study

Low vitamin D status has been associated with cardiovascular disease (CVD) and mortality primarily in selected groups, smaller studies, or with self-reported vitamin D intake. We investigated the association of serum vitamin D status with the incidence of a registry-based diagnosis of ischemic heart disease (IHD), stroke, and all-cause mortality in a large sample of the general population. A total of 9,146 individuals from the two population-based studies, Monica10 and Inter99, were included. Measurements of serum 25-hydroxyvitamin D at baseline were carried out using the IDS ISYS immunoassay system in Monica10 and High-performance liquid chromatography in Inter99. Information on CVDs and causes of death was obtained from Danish registries until 31 December 2008. There were 478 cases of IHD, 316 cases of stroke, and 633 deaths during follow-up (mean follow-up 10 years). Cox regression analyses with age as underlying time axis showed a significant association between vitamin D status and all-cause mortality with a HR = 0.95 (P = 0.005) per 10 nmol/l higher vitamin D level. We found no association between vitamin D status and incidence of IHD or stroke (HR = 1.01, P = 0.442 and HR = 1.00, P = 0.920, respectively). In this large general population study, the observed inverse association between serum vitamin D status and all-cause mortality was not explained by a similar inverse association with IHD or stroke.