Should You Still Take Vitamin D in the Summer?

There’s a reason vitamin D is called the Sunshine Vitamin: Your body produces this hormone-like vitamin whenever your skin is exposed to a significant amount of direct sunlight. Knowing this, it’s easy to assume that you’ll naturally get enough vitamin D in the summer. Nutritionists warn that this may not be the case, however. Before you completely abandon your vitamin D supplements, consider this: research indicates that as many as 41% of adult Americans are vitamin D deficient year round.

How can you tell if you need to keep supplementing, or if summer can take care of your vitamin D needs? There are a few things to consider when trying to decide if you should still take vitamin D in the summer. We outline them below.

Vitamin D Tests

The most definitive way to know if you need supplemental vitamin D in the summer is to get a blood test. It’s the only way to know for certain if your vitamin D levels are normal or if you have a vitamin D deficiency. You can schedule a vitamin D test with your primary care physician, who will be able to read your labs and tell you exactly how much vitamin D you should be taking. Additionally, there are a few companies who offer in-home testing options. If you go this route, be warned that understanding how to read and adjust your vitamin D levels can be complex. Most health care professionals recommend consulting a physician.


The sun’s rays are strongest at the equator and weaker at points further from that midline. People who live in warmer climates closer to the equator are more likely to get enough sunlight to produce adequate levels of vitamin D. Meanwhile, those living further from the equator in cooler climates may find that they’re more likely to experience a  vitamin D deficiency. According to WebMD, in the U.S. only people who live south of a line drawn from Los Angeles to Columbia, S.C. get enough sunlight for vitamin D production throughout the year. 

Skin Tone

Your location can affect the amount of sunlight you’re exposed to, but your skin tone plays a role, too.  Those with darker skin tones may need more sunlight exposure to produce optimal levels of vitamin D, whereas those with lighter skin tones more sensitive to the effects of the sun may produce vitamin D more quickly.

Immune Function and Autoimmune Disease

The link between vitamin D and autoimmune diseases is still being explored. It was once thought that vitamin D deficiency caused autoimmune disorders. However, research now indicates that vitamin D deficiency may be a result of many autoimmune diseases, not a cause. Regardless, many doctors recommend supplementing with vitamin D to combat this deficiency. Especially in the case of diagnosed diseases, however, you should always consult your physician when making an adjustment to your supplement regimen or your diet. 

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.