Does Sunlight Through Glass Provide Vitamin D?

Q. Does sunlight through window glass provide vitamin D? A. Sunlight doesn’t actually “provide” you with vitamin D. Rather, your body produces vitamin D when skin is exposed to the sun’s ultraviolet rays, which trigger vitamin D synthesis. The liver and kidneys convert this biologically inert form of vitamin D into biologically active forms the … Read more

Are Calcium Supplements Safe?

Q. Are calcium supplements safe? A. The short answer is probably yes. Many people, especially women, take calcium supplements in the hope of building stronger bones, but whether calcium supplements prevent fractures remains uncertain. The United States Preventive Services Task Force advises postmenopausal women against taking 1,000 milligrams a day or less for preventing fractures … Read more

Older Americans Are ‘Hooked’ on Vitamins

Too Much of a Good Thing Taking megadoses of vitamins and minerals, using amounts that people could never consume through food alone, could be even more problematic. “There’s something appealing about taking a natural product, even if you’re taking it in a way that is totally unnatural,” Ms. Price said. Early studies, for example, suggested … Read more