Still, federal guidelines recommend that in general, to maintain good bone health and normal calcium metabolism, people between 1 and 70 years of age should get 600 international units (or 15 micrograms) each day — from foods, supplements or both. Those over 70 should get 800 I.U. (or 20 micrograms), according to the guidelines, and infants up to 12 months need 400 I.U. (or 10 micrograms).
“But many organizations don’t feel those numbers are high enough,” Ms. Stefanski said. For example, the Endocrine Society — which recommends a blood level of 40 to 60 nanograms per milliliter — says that most adults can safely take between 1,000 to 2,000 I.U. (or 25 to 50 micrograms) of vitamin D per day from either supplements or a combination of food and supplements.
If you’re concerned about a deficiency, are at risk for osteoporosis or have a condition that affects how you absorb nutrients, talk with a health care provider about getting your vitamin D level tested.
How to get vitamin D without the sun
While winter’s chill is in the air, you’ll likely need to look beyond the sun to satisfy your vitamin D needs, Dr. Young said.
Foods that supply the highest amounts of naturally occurring vitamin D include fatty fish (like salmon, tuna and sardines), cod liver oil, beef liver, egg yolks and some mushrooms. But because the typical American diet tends not to include many or enough of those foods, manufacturers have been fortifying foods with vitamin D since the 1930s. Good sources of vitamin-D-fortified foods are cow’s milk, soy milk, cereal and orange juice. Keep in mind, though, that it can be challenging to get enough vitamin D from food sources alone, Ms. Stefanski said. And not all dairy products are fortified with vitamin D, so make sure to check the nutrition facts label.
“Especially as we’re entering the winter months,” Ms. Stefanski said, “most people would benefit from taking a supplement.”
When looking for a supplement, choose vitamin D3 over vitamin D2, Ms. Stefanski said, since research suggests you can absorb it more effectively. Also, look for a supplement that has the U.S.P. Verified Mark on the bottle, which indicates that the product contains the ingredients listed on the label and does not contain harmful contaminants.
