Everyone knows that going out in the sun without sunscreen is bad, bad, bad. Right? Not so fast. “The push to prevent skin cancer may have come with unintended consequences,” Diane Welland wrote in an article for Scientific American. See, one of the easiest ways to get vitamin D, which helps neurotransmitters work, is to let the sun shine in. But if you slather your skin with sunscreen, your body can’t soak up that delicious vitamin D. People who use sunscreen all the time can create problems for their brains.
A study conducted by a group of European scientists found that subjects with vitamin D deficiency performed poorly on a number of tests. The less vitamin D they had, the worse their performance.
The body can get vitamin D from two sources—food and the sun. This vitamin is known as the “sunshine vitamin” because the body can make vitamin D after sunlight hits the skin. Your body’s ability to produce vitamin D from sunlight diminishes with age; therefore, requirements increase for older adults. Foods rich in vitamin D include fortified milk or juice, salmon, tuna, mushrooms, mackerel, and fortified breakfast cereals.
Because vitamin D is a fat-soluble vitamin, it can be toxic in larger doses. Toxicity can lead to kidney stones or damage, weakened muscles and bones, excessive bleeding, and other health problems. Levels high enough to cause health complications usually come from supplements, not from food or too much sunlight. If you take a supplement that includes vitamin D, make sure it does not contain more than you need for your age range and gender. Vitamin D has a UL (upper limit) set at 50 micro grams (mcg) or 2,000 IUs (international units) per day for children and adults. There is no UL established for infants.