To investigate the relationship between vitamin D status in healthy women and cardiovascular outcome.
Design and methods
Between 1990 and 1993, 2016 healthy, recently postmenopausal women were enrolled in the Danish Osteoporosis Prevention Study. Serum levels of 25-hydroxyvitamin D (25(OH)D, nmol/l) were measured at baseline. Participants were followed for 16 years. The primary end point was a combination of death, heart failure, myocardial infarction (MI) and stroke. Vitamin D deficiency was defined as serum 25(OH)D<50 nmol/l. The primary end point was adjusted for other risk factors of adverse cardiovascular events (age, smoking, blood pressure, hip–waist ratio, education and family history of MI).
At baseline, mean age was 50 years and BMI 25. Women with vitamin D deficiency (n=788) had more cardiovascular risk factors than vitamin D-replete women (n=1225). Compared with vitamin D-replete women, women with low 25(OH)D levels had significantly higher BMI and triglycerides, lower HDL and hip–waist ratio and less education. More were smokers among the vitamin D deficient (47 vs 38%). A primary end point was experienced by 118 (15%) with vitamin D deficiency and by 125 (10%) of the vitamin D replete. Hazard ratio (HR) was 1.49 (95% confidence interval: 1.16–1.92; P=0.002) in the vitamin D deficient. Adjusted HR was 1.32 (1.02–1.71; P=0.03). In total, 135 women died; of these, 65 (8%) were of the vitamin D deficient and 70 (6%) in the vitamin D-replete group; unadjusted HR was 1.44 (1.02–2.01; P=0.04) for vitamin D deficiency.
Healthy women with vitamin D deficiency have increased risk of adverse cardiovascular outcome.