How to Get the Benefits of Vitamin D

Are you getting enough vitamin D?

Chances are, you may not be, even if you spend a lot of time in the sun. Research shows that many Americans are woefully deficient in this key nutrient, a deficiency that’s linked to a host of ailments, including cardiovascular disease, hypertension, type 2 diabetes, many types of cancer, asthma, cognitive impairment, depression, and — yes — obesity. In fact, studies have found that a deficiency in vitamin D can hamper a person’s ability to lose weight effectively. So how do you know if you’re deficient? And if you are, what should you do about it? Here are some suggestions.


Get tested
Ask your doctor if you can have a vitamin D analysis done as part of your routine blood work at your next physical (it typically costs about $100 and may or may not be covered by your insurance). If you have a 25-hydroxyvitamin D level below 20 ng/ml (nanograms per milliliter), you are considered deficient in D. Optimal levels for individuals can vary widely, however, ranging from 20 ng/ml to above 50 ng/ml, depending on a person’s metabolism and other factors. Because vitamin D levels can also vary by season (and are particularly low in the late winter and early spring), you may have to have the test done more than once to be certain you really are deficient.

Catch some rays
Vitamin D is known as the sunshine vitamin because the body produces it after being exposed to sunlight. Studies show that spending 10 to 15 minutes in the sun while unprotected (that is, without sunscreen on your face, hands, arms, and legs) two to three times a week can boost your vitamin D levels; less time may be needed in warmer climates. If you’re planning to be out in the sun for more than 15 minutes, however, be sure to apply the appropriate amount of sunscreen.

Eat vitamin D–rich foods
Eating a healthy diet can help increase your vitamin D levels. Foods that are natural sources of vitamin D are sardines, mackerel, herring, and salmon. Vitamin D–fortified foods, such as low-fat or fat-free milk, reduced-fat cheese, and some whole-grain cereals, can also help you get more of this vitamin into your body. Also consider cod liver oil (1 tablespoon provides 1,360 IU!).

Consider a supplement
Consult with your doctor about taking a daily vitamin D supplement if you cannot get adequate amounts of vitamin D from foods and/or sun exposure and especially if you are pregnant or considering pregnancy. While vitamin D supplementation has been deemed safe up to 10,000 IU a day, don’t start taking large amounts without a doctor’s permission. If you have children, talk with your pediatrician about vitamin D testing and supplementation, since many children, including breast-feeding babies and children who are overweight or obese, have been found to be deficient. To make better use of a vitamin D supplement, take it with your largest meal of the day. Researchers believe that the nutrient, which is fat-based, is absorbed better with food that also contains some fat.