Epidemiology of multiple sclerosis and vitamin D levels in Lanzarote, Canary Islands, Spain

Abstract

Background Low levels of 25-hydroxyvitamin D (25(OH)D) have been described as one of the possible environmental factors involved in multiple sclerosis (MS) etiopathogenesis. Objectives To study epidemiology of MS and 25(OH)D serum levels of patients in Lanzarote (29°02′06″N), a region with high ultraviolet radiation values during the whole year which is located far apart from Iberian Peninsula (36°–43°N), but without genetic/ethnic differences with it. Methods Incidence in Lanzarote was assessed according to McDonald 2005 criteria between January 2008 and December 2015 and prevalence date was 12/31/15. For 25(OH)D serum levels analyses, samples from 60 MS patients and 60 healthy donors (HD) were collected monthly in a one-year prospective study. Results The prevalence of MS in Lanzarote was 50.0/100,000 and the incidence per year was 2.5/100,000. Median 25(OH)D levels values were 29.1 ng/ml for MS patients (maximum = 36.1 ng/ml, minimum = 22.5 ng/ml) and 27.1 ng/ml for HD (maximum = 34.8 ng/ml, minimum = 22.8 ng/ml). There were no significant differences between 25(OH)D serum levels between MS patients and HD. Conclusions Lanzarote possesses lower prevalence and incidence values than peninsular Spain. Moreover, 25(OH)D serum levels do not differ between MS patients and HD.