Q. I know that we need Vitamin D for absorption of calcium. Do you make Vitamin D if the sunlight is coming through glass (when you’re riding in a car or sitting by a window)?
A. The body makes vitamin D when skin is exposed to sunshine. Ultraviolet B rays are primarily responsible for this process, and window glass protects against most UVB exposure. Consequently, it is hard to get a tan or make vitamin D indoors.
Vitamin D is crucial for building strong bones. This nutrient also appears to help prevent heart disease, depression and certain cancers. A new study from Harvard has found that lung cancer patients who got more sun and had high levels of vitamin D had much better survival rates.
Fifteen minutes of sun exposure two or three times a week may be all it takes to make adequate amounts of vitamin D. For those who cannot tolerate even that much sun, a supplement might do the trick.
