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While some vitamin and mineral deficiencies are very rare in the U.S., others are fairly common and can have profound impacts on overall health. If you’re looking at magnesium vs. vitamin D for deficiency, for example, you’ll have two incredibly important nutrients of which many people don’t get enough.
Meet the experts: Kathleen Garcia-Benson, R.D.N., C.S.S.D., C.P.T., a registered dietitian nutritionist with VNutrition; Stephanie Crabtree, M.S., R.D., a holistic registered dietitian in Venice, FL.
“Vitamin D deficiency is more commonly diagnosed in the U.S., but low magnesium intake is also very widespread and often underrecognized,” says Kathleen Garcia-Benson, R.D.N., C.S.S.D., C.P.T., a registered dietitian nutritionist with VNutrition. Read on to find out what you should know about each of these micronutrient deficiencies, plus the crucial link between them.
How common is magnesium deficiency?
According to the Cleveland Clinic, only about 2% of healthy adults are deficient in magnesium to the point that it causes noticeable symptoms. However, low magnesium intake—a.k.a. falling short of the recommended 310 to 420 milligrams (mg) per day—is much more widespread. “Over half of Americans don’t meet magnesium needs from food,” says Stephanie Crabtree, M.S., R.D., a holistic registered dietitian in Venice, FL. “Many people simply aren’t eating enough magnesium-rich whole foods, and processed diets tend to displace them.”
What’s more, research suggests that modern farming and processing practices dramatically reduce the amount of magnesium contained in foods that have traditionally been rich in the mineral, making it even harder to get enough from your diet.
“Another consideration is that chronic stress increases the body’s need for magnesium, and with stress being so prevalent, that can further contribute to low or marginal levels over time,” explains Crabtree. Garcia-Benson adds that certain common medications, such as diuretics, antibiotics, and proton pump inhibitors, can also cause magnesium loss, further increasing your needs for the mineral.
Why should you be concerned about not getting enough magnesium? According to the National Institutes of Health (NIH), magnesium plays key roles in maintaining healthy blood pressure and blood sugar levels, optimizing energy production, and supporting muscle and nerve function. Possible low magnesium symptoms can include muscle cramps, anxiety, an irregular heartbeat, headaches, trouble sleeping, and more.
How common is vitamin D deficiency?
Roughly 35% of American adults are deficient in vitamin D, per the Cleveland Clinic. “Vitamin D insufficiency is common because of both where we live and how we live,” says Crabtree. There are three ways to get vitamin D: through sun exposure on your skin, through food, and through supplements. While you technically should be getting most of your vitamin D from the sun, it’s incredibly tricky to meet your needs. “In the northern U.S., UVB rays aren’t strong enough in certain months to produce vitamin D from sun exposure,” Crabtree explains. Indoor lifestyles, sun protection habits, and darker skin pigmentation can also all reduce vitamin D synthesis from the sun. “As a result, many people rely more heavily on food and supplements to meet their needs,” Crabtree says.
However, vitamin D is not naturally present in very many foods. Per the NIH, top sources include cod liver oil, fatty fish, certain mushrooms, and eggs. For this reason, many people rely on foods that are fortified with vitamin D, such as dairy and nondairy milk and cereal, but these often contain less than 20% of the recommended 15 micrograms (mcg) per day per serving.
Possible symptoms of vitamin D deficiency include fatigue, sweating, joint pain, and signs of bone weakness, such as falling or breaking bones or a diagnosis of osteopenia or osteoporosis.
The link between magnesium and vitamin D deficiency
Magnesium and vitamin D deficiency are closely related, with one directly increasing the likelihood of the other. “Magnesium is required to activate vitamin D in the body,” explains Garcia-Benson. “Low magnesium can make vitamin D less effective.” One study published in the Clinical Kidney Journal confirmed that magnesium deficiency may lead to reduced concentrations of vitamin D in the body.
“This is one reason vitamin D levels don’t always improve as expected with supplementation alone,” Crabtree notes. In fact, correcting a vitamin D deficiency may require addressing your magnesium status as well. “Since magnesium is required for vitamin D activation, ensuring sufficient intake helps the body use vitamin D more effectively,” Crabtree explains.
What to do if you suspect a deficiency
If you suspect that you are deficient in magnesium or vitamin D, either because you’re experiencing symptoms, don’t eat a lot of foods high in magnesium (such as nuts, seeds, legumes, and leafy greens), or hardly spend any time in the sun, Crabtree says the first thing you should do is talk to your healthcare provider who can order the appropriate tests. “Vitamin D can be tested directly,” she explains. “Magnesium status is harder to assess in bloodwork. Standard blood tests don’t always reflect true status, and more specialized testing like RBC (red blood cell) magnesium may be used in some cases.” From there, you can determine the best course of action for you, which may involve both supplements and dietary adjustments. The more personalized guidance you get, the faster you’ll see results.
Dietary supplements are products intended to supplement the diet. They are not medicines and are not intended to treat, diagnose, mitigate, prevent, or cure diseases. Be cautious about taking dietary supplements if you are pregnant or nursing. Also, be careful about giving supplements to a child, unless recommended by their healthcare provider.
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