Are you getting enough vitamin D? This vital nutrient comes from the sun, food, and supplements. A blood test is the best way to determine if your levels are normal, explains the National Institutes of Health (NIH).
“Vitamin D is needed for health and to maintain strong bones. It helps the body absorb calcium (one of the bone’s main building blocks) from food and supplements. People who get too little vitamin D may develop soft, thin, and brittle bones, a condition known as rickets in children, and osteomalacia in adults,” states the NIH.
“Muscles need vitamin D to move, nerves need it to carry messages between the brain and every body part, and the immune system needs vitamin D to fight off invading bacteria and viruses. Together with calcium, vitamin D also helps protect older adults from osteoporosis,” the NIH adds.
Daily vitamin D needs vary with age. Babies need 400 International Units (IU), people one to 70 years of age need 600 IU; while those over age 70 need 800 IU. Many foods are fortified with vitamin D to supplement the American diet, since very few foods contain it naturally. Almost all of the U.S. milk supply is fortified with 400 IU of vitamin D per quart.
The NIH lists foods richest in vitamin D, including fatty fish such as salmon, tuna, and mackerel. Beef liver, cheese, and egg yolks contain small amounts. Mushrooms provide scant vitamin D. Various mushroom varieties have been exposed to ultraviolet light, which bolsters the vitamin D content.
The NIH adds that the body makes vitamin D when skin is directly exposed to the sun, which helps most people meet some of their vitamin D needs. Skin exposed to sunshine indoors through a window does not produce Vitamin D. Tanning bed use allows the skin to produce vitamin D, but it may pose skin cancer risks.