More and more studies are revealing the benefits of having plenty of D—and the dangers of having too little. Use this comprehensive guide to make sure you're getting the amounts you need.
For decades vitamin D's claim to fame was its role as calcium's trusty escort, helping our bones absorb the essential mineral. But a recent flood of research is revealing that D does much more: "There is a vitamin D receptor on every one of our cells," says Michael F. Holick, PhD, MD, author of The Vitamin D Solution.
"And those receptors are there for a reason." Actually, many reasons—all of our bodily functions seem to rely on the nutrient, and studies show that it's key to helping prevent everything from migraines to cancer.
The trouble is, most of us—53 percent of women, 41 percent of men, and 61 percent of kids—have insufficient levels. Though our bodies naturally produce the vitamin from the sun's UV-B rays, these days we don't absorb nearly enough sunlight to manufacture an adequate amount—and during winter, most of the country gets so little sun, doing so is impossible. But don't sweat it: With a few easy moves, you can boost your D levels. We've gathered the latest info on the vitamin everyone's suddenly talking about.
High levels of vitamin D are linked to...