The Connection Between Magnesium And Vitamin D Explained

If you are deficient in vitamin D, it may not actually be because you're not consuming enough vitamin D. Surprisingly, low magnesium might be to blame.

A 2018 study found that having enough magnesium is critical in optimizing vitamin D status in the body, both by raising it when levels were low and in lowering it when levels were high. "Vitamin D insufficiency is something that has been recognized as a potential health problem on a fairly large scale in the U.S.," the study's coauthor, Martha Shrubsole, said in a press release. "In addition to vitamin D, however, magnesium deficiency is an under-recognized issue. Up to 80 percent of people do not consume enough magnesium in a day to meet the recommended dietary allowance (RDA) based on those national estimates."

And without enough magnesium, Shrubsole explained, the body will struggle to regulate vitamin D levels, which are critical for preventing autoimmune disorders, osteoporosis, cardiovascular disease, and even some cancers (via Precision Nutrition).

Should you supplement with both vitamin D and magnesium?

In 2018, the American Osteopathic Association released research showing that 50% of Americans are magnesium deficient. That deficiency causes them to be vitamin D deficient as well, as magnesium is needed to metabolize vitamin D for use in the body. "By consuming an optimal amount of magnesium, one may be able to lower the risks of vitamin D deficiency and reduce the dependency on vitamin D supplements," study co-author Mohammed S. Razzaque said in the press release, adding that without appropriate amounts of magnesium, vitamin D supplements are "not really useful or safe."

Researchers recommend that if you're low in vitamin D, you should also have your magnesium levels checked since the two are so closely linked and vitamin D relies on adequate magnesium, per a review in the American Journal of Therapeutics.

Magnesium can be easily found in whole food form by consuming more leafy greens, whole grains, nuts and seeds, and legumes. Women should aim to consume around 310 to 320 milligrams per day and men should shoot for 400 to 420 milligrams (via the National Institutes of Health).