Sun exposure and vitamin D are independent risk factors for CNS demyelination

R. M. Lucas, A. L. Ponsonby, K. Dear, P. C. Valery, M. P. Pender, B. V. Taylor, T. J. Kilpatrick, T. Dwyer, A. Coulthard, C. Chapman, I. Van Der Mei, D. Williams, A. J. McMichael