Narrator: This is Science Today. The rate of multiple sclerosis is on the rise — especially among women. University of California, San Francisco, doctors say that a vitamin D deficiency could be to be blame.
Green: Vitamin D is actually a molecule, a steroid hormone that we manufacture in response to sunlight. In our modern age many of us are vitamin D deficient because we don't get adequate sunlight exposure. In fact, in the last five or 10 years we've learned that there is bordering on an epidemic of vitamin D deficiency in the population.
Narrator: Ari Green, the assistant director of UCSF's Multiple Sclerosis Center, explains that widespread concern over developing skin cancer compels many people to avoid sun exposure as much as possible.
Green: UV is a double-edged sword. Ultraviolet radiation does contribute to and potentially cause different forms of skin cancer, including melanoma. Some of us think, however, that we probably get to the point of way too much sunlight avoidance and way too much vitamin D deficiency that has other health consequences.
Narrator: For Science Today, I'm Larissa Branin.