he role of vitamin D, most often measured as circulating 25-hydroxyvitamin D (25(OH)D), also designated calcidiol), in cardiovascular disease (CVD) remains much debated. Whereas the strongest support for the notion that low vitamin D levels promote CVD comes from some prospective studies of incident cardiovascular events or CVD mortality, [1][2][3] other prospective studies of the relationship between the circulating 25(OH)D concentration and risk of CVD have provided discrepant results. [4][5][6] Similarly, crosssectional studies, hitherto restricted to fairly small, diverse, and specific populations, on the relationship between 25(OH) D and carotid intima-media thickness (IMT), a widely used surrogate marker of subclinical atherosclerosis 7 and predictor of coronary and cerebrovascular events, 8,9 have shown contradictory results. [10][11][12][13][14] This also pertains to the studies examining the associations of vitamin D metabolites and the vitamin D metabolism gene CYP24A1 with coronary artery calcification. 12,[15][16][17][18] See accompanying article on page 2467 © 2013 American Heart Association, Inc. Objective-Vitamin D deficiency has been implicated in cardiovascular disease and is associated with multiple cardiovascular risk factors. We investigated the serum 25-hydroxyvitamin D (25(OH)D) concentration in relation to latitude, baseline carotid intima-media thickness (IMT), and IMT progression, the carotid IMT measures being surrogate markers of subclinical atherosclerosis and cardiovascular disease risk.
Approach and Results-Serum 25(OH)D concentration was related to high-resolution carotid IMT measures in 3430middle-aged and elderly subjects with high cardiovascular risk but no prevalent disease, who were recruited at 7 centers in Finland, Sweden, The Netherlands, France, and Italy. Participants underwent carotid ultrasound examination at baseline and at months 15 and 30 after entry into the study, whereas blood samples, clinical data, and information about lifestyle were collected at baseline. Serum 25(OH)D levels were positively associated with latitude (Jonckheere-Terpstra χ=166.643; P<0.001) and, as previously reported, associated with a range of cardiovascular risk factors. There were no independent relationships between 25(OH)D and segment-specific or composite IMT measures in the entire cohort. In analyses stratified by sex, diabetes mellitus, and statin treatment, weak associations with some baseline and progression measures of carotid IMT were observed in males, diabetics, and nonstatin-treated individuals. 19 enabled us to explore whether potential latitude-related differences in vitamin D concentrations contribute to differences in subclinical atherosclerosis. By enrolling roughly the same numbers of male and female participants from different parts of Europe, this study allows results to be interpreted in a wider context than in previous studies. Finally, the present study, to the best of our knowledge, represents the first attempt to investigate 25(OH)D levels in relation to progressio...