FACTS: VITAMIN D

What do the following conditions have in common: osteoporosis, multiple sclerosis, high blood pressure, diabetes and cancer? Give up? Experts suspect that insufficient levels of vitamin D raise your risk of getting these diseases. Unfortunately, most of us probably are vitamin D deficient.

About all I was taught in medical school is that vitamin D keeps bones strong. Recently however, this area of study has exploded as scientists uncover the vitamin’s far-reaching effects. Because it increases calcium levels, vitamin D indirectly fortifies bones and teeth. It also regulates cells all over the body, which explains vitamin D’s disparate roles, such as influencing insulin production and immune function, as well as helping prevent inflammation and cancer.

The scary thing is that vitamin D deficiency appears to be quite common. A recent British study found that 87 percent of volunteers had low blood levels of the vitamin in winter and spring, and 61 percent had low levels in summer and fall. Why the seasonal variation? Our chief source of vitamin D is sunshine.