What is vitamin D3?Taya Zaria/Shutterstock
First things first. Vitamin D3 (also known as cholecalciferol) is the most common and bioavailable form of vitamin D. You can get it from a few foods (usually fortified ones, though the quantities are small), but the most common route is from sunlight on your skin. Although the vitamin is essential for a long list of bodily functions, many people don’t get nearly enough—especially in the winter. “Most people need supplements,” says Jessica Levinson, MS, RDN, CDN. Recent studies estimate that more than one billion people have low levels of vitamin D. Also, note that sunblock—which is essential for all these compelling reasons—inhibits the production and absorption of vitamin D3.
How much you need and how best to actually get itMarian Weyo/Shutterstock
The FDA recommends between 600 and 4000 IU per day for children and adults, but it can be hard to meet this dose in winter. “Vitamin D3 isn’t found in many foods, but some dairy products, cereals, and grains are fortified with vitamin D3 to help people increase their intake,” says Craig Elbert, CEO of Care/of.
“Fatty fish such as salmon, tuna, and sardines as well as eggs and shiitake mushrooms are other dietary sources of vitamin D3, but it’s important to note that the absorption of vitamin D3 from our foods is dependent on adequate bile presence and adequate iron status,” says nutrition expert Pam Machemehl-Helmly, BS, founder and chief science officer of Wellnicity. As mentioned, even in those foods with vitamin D3, there may not be enough of the vitamin present to get enough. Test your blood levels to know your status.