Scientists have long suspected that sunshine and vitamin D may protect against the development of multiple sclerosis; now they have additional evidence.
Oxford University researchers hypothesized that if solar radiation is protective, multiple sclerosis patients probably would have less solar exposure -- and thus lower rates of skin cancer. They then examined skin cancer rates among more than 432,000 Oxford-area patients treated by England's National Health Service from 1963 to 1999.
Among the more than 5,000 patients with MS, the prevalence of skin cancers was significantly lower than average. The authors suggested that a minimum amount of sun exposure might guard against the neurological disease, perhaps by damping down the immune system.
The study, published in the February Journal of Epidemiology and Community Health, follows a report in the Jan. 13 issue of the journal Neurology that women who took vitamin D supplements of at least 400 international units per day reduced their risk of developing MS by as much as 40%. There are two basic ways to get vitamin D: by taking supplements or by exposure to sunshine, which helps the skin produce it.
-- Jane E. Allen