BACKGROUND Some animal and human studies suggest that vitamin D supplementation may lower blood pressure (BP), and a large prospective study found that the risk of incident hypertension (HTN) was inversely related to plasma levels of 25(OH) vitamin D. Accordingly, we studied the relation between baseline levels of 25(OH) vitamin D and changes in BP in postmenopausal women enrolled in the Women’s Health Initiative (WHI).
METHODS - Baseline serum vitamin D levels were measured in 4867 participants in 2 nested case-control studies in the WHI calcium/vitamin D trial. Vitamin D quartiles (<34.4, 34.4–47.6, 47.7–64.6 and 64.7 nmol/L) were created based on the levels in the combined140/90 or treatment with antihypertensive medication.
CONCLUSIONS In postmenopausal women, there was no association of the level of 25(OH) vitamin D with change in BP over 7 years of follow-up.