The big D. Looking for links between type 2 diabetes and vitamin D.

摘要

Sun exposure is a tricky thing. No one wants too much, of course, but too little can also be a problem. That's because sunshine encourages skin cells to produce vitamin D, a substance that keeps bones strong and may play an as yet undetermined role in warding off a variety of other ailments. There was a time when lack of vitamin D was a problem only for people living in the far north, where months could go by with no more than a few hours of weak light a day. For the rest of the world, simply spending time outside was sufficient to keep the blood's D levels healthfully high. "In the right location, less than half an hour outside can give you all the vitamin D you need for a week," says Susan Harris, DSc, a researcher at Tufts University. But these days-between office jobs, television, long commutes, and, of course, sunblock-regular sun exposure is hard to come by. "It wasn't till industrialization' that we started spending all of our time inside," says Harris. "Now... we depend more on dietary sources [of vitamin D], of which there are few-and most of us don't get enough." Fortified foods like milk and cereal, in addition to fatty fish like salmon and mackerel, can make up for some of what we're missing, but most of us also need either appropriate sun exposure or vitamin D supplements.