Lack of Sunshine Linked to MS, Arthritis

A lack of sunshine makes people more likely to contract diseases including arthritis, multiple sclerosis, Type 1 diabetes, and some cancers, according to scientists exploring the genetic link between disease and low levels of vitamin D. Genetic researchers found that the vitamin—which the body makes when the skin is exposed to sunlight—affects 229 genes related to autoimmune diseases, the Guardian reports.

Many of the diseases involved are much more common in sunlight-starved northern parts of the world, the researchers say, suggesting that taking vitamin D supplements during pregnancy and childhood could help prevent many diseases. "Rather than arguing whether these conditions are caused by nature or nurture, it is very clear that most of these things are actually nature and nurture—the environment interacting with a gene," says one of the study's authors. (More arthritis stories.)