Serum 25-hydroxyvitamin D predicts severity and prognosis in stroke patients

Background and purpose: We aimed to evaluate the association between 25-hydroxy-vitamin D (25(OH) D) levels and both clinical severity at admission and outcome at discharge in stroke patients. Methods: From February 2010 to December 2010, consecutive stroke patients admitted to the Department of Neurology of Dijon, France, were identified. Clinical information was collected. Serum concentration of 25(OH) D was measured at baseline. Stroke severity was assessed at admission using the NIHSS score. Functional impairment was evaluated at discharge using the modified Rankin scale (m-Rankin). Multivariate analyses were performed using logistic regression models. Results: Of the 386 recorded patients, serum 25(OH) D levels were obtained in 382 (median value = 35.1 nM; IQR = 21-57.8). At admission, 208 patients had a NIHSS <= 5, with a higher mean 25(OH) D level than that observed in patients with moderate-to-high severity (45.9 vs. 38.6 nM, P < 0.001). In multivariate analyses, a 25(OH) D level in the lowest tertile (<25.7 nM) was a predictor of a NIHSS >= 6 (OR = 1.67; 95% CI = 1.05-2.68; P = 0.03). The mean 25(OH) D level was lower in patients with moderate-to-severe handicap at discharge (m-Rankin 3-6) than in patients with no or mild handicap (35.0 vs. 47.5 nM, P < 0.001). In multivariate analyses, the lowest tertile of 25(OH) D level (<25.7 nM) was associated with a higher risk of moderate-to-severe handicap (OR = 2.06; 95% CI = 1.06-3.94; P = 0.03). Conclusion: A low serum 25(OH) D level is a predictor of both severity at admission and poor early functional outcome in stroke patients. The underlying mechanisms of these associations remain to be investigated.