Vitamin D deficiency and osteoporosis in stroke survivors: an analysis of National Health and Nutritional Examination Survey (NHANES)

Background and purpose—An inverse association between 25-hydroxyvitamin D (25[OH]D) levels and stroke was emphasized in recent studies. Our objective was to determine the rate of Vitamin D deficiency and risk of associated osteoporosis among stroke survivors in a nationally representative population. Methods—Participants from the National Health and Nutritional Examination Survey (NHANES) from 2001 to 2006 were included. Stroke survivors were then divided into two groups depending on serum 25(OH)D levels: <30 ng/dl as Vitamin D deficiency and ≥30 ng/dl as normal. Comparisons of demographics and risk factors between two groups were performed using SAS software. Multivariate analysis was performed to determine the association between Vitamin D deficiency and osteopororis in stroke survivors after adjusting for potential confounding factors. Results—There were 415 (4.0%) stroke survivors among 10,255 participants in NHANES. The mean age (±SD) of stroke survivors was 67.6 (±17.3) years and 211 (50.8%) were men. Mean 25(OH)D concentrations were not significantly different in patients with stroke (20.3 versus 21.8 ng/ml, p = 0.65) although the rate of osteoporosis was significantly higher among stroke survivors (17.9% versus 6.9%, p < 0.0001). Out of 415 stroke patients, Vitamin D deficiency was seen in 71.0% of patients. The rates of osteoporosis were similar between patients with or without Vitamin D deficiency. After adjusting for potential confounders, there was no association between Vitamin D deficiency and osteoporosis. Conclusions—Vitamin D deficiency and osteoporosis are highly prevalent among stroke survivors; however, there does not appear to be a relationship between the two entities.