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.