Neonatal vitamin D status and risk of multiple sclerosis

Objective: Low vitamin D status at birth may be associated with risk of adult onset multiple sclerosis, but this link has not been studied directly. We assessed the relation between neonatal vitamin D concentrations, measured in stored blood samples, and risk of multiple sclerosis. Methods: This was a population-based case-control study in Sweden including 459 incident cases of multiple sclerosis and 663 controls, randomly drawn froma national population registry and frequency matched on sex, age, and residential area. Results: There was no association between neonatal 25-hydroxyvitamin D quintile and risk of multiple sclerosis (crude odds ratio = 1.0, 95% confidence interval = 0.68-1.44, for the highest quintile compared to the lowest). Adjusting for a number of potential confounding factors in early life (month of birth, latitude of birth, breastfeeding) and in adult life (25-hydroxyvitamin D, sun exposure, vitamin D intake from dairy products, fatty fish consumption, smoking, body mass index at 20 years of age) as well as ancestry, multiple sclerosis heredity, and socioeconomic group did not considerably affect the result. Interpretation: At a broad population level, 25-hydroxyvitamin D at birth was not associated with risk of multiple sclerosis.