How prevalent is a magnesium deficiency?

Despite magnesium’s importance to human health, many of us have less than an optimal level. According to World Health Organization statistics, as many as three out of four U.S. adults do not meet the FDA’s Recommended Daily Intake for magnesium.1

Why is a magnesium deficiency so common?

Many things can contribute to a magnesium deficiency. Some chronic diseases, like diabetes and metabolic syndrome, can increase the need for magnesium, while some medications can result in low magnesium levels.

But even if you’re healthy, have a good diet, and take no medications, you could still not be taking in an optimal amount of magnesium. For example, a decreased intake can occur because of magnesium-depleted soil where vegetables and fruits are grown. By some estimates, the magnesium levels in some vegetables like cabbage, lettuce, and spinach have dropped by 80 percent in the past 100 years.2

An increased dependence on quick-to-prepare, processed foods has also resulted in decreased magnesium intake. Soft drinks with phosphates (that provide the fizz) interfere with magnesium absorption, while the diuretic-like effect of caffeine and alcohol increase magnesium loss in the urine.

Who is the most at-risk for a magnesium deficiency?2,3

  • Individuals who have diabetes or other blood sugar abnormalities, such as insulin resistance and metabolic syndrome. Why?  Because of increased urinary excretion, decreased dietary intake, and increased need.
  • Individuals who consume a diet high in pastries and other junk foods. Why? Because there is very little magnesium in these foods.
  • drink large amounts of alcohol. Why? Because of magnesium loss in the urine, likely poor diet, and chronic GI problems that inhibit absorption.
  • Individuals who take diuretics – like thiazide diuretics for blood pressure. Why? Because these medications increase magnesium loss in the urine.  This is of particular importance in this population because magnesium helps maintain healthy blood pressure levels.*
  • Individuals who have a vitamin D deficiency – according to some statistics, it’s 40 percent of U.S. adults. Why? Because these individuals can also be magnesium deficient, which is essential for vitamin D’s activation and metabolism.
  • Individuals who are on long-term antibiotic use, such as tetracyclines and quinolones. Why? Because these medications can combine with magnesium to form insoluble “soaps” that can’t be absorbed.
  • Individuals who use proton pump inhibitors or H2 blocker antacids. Why? Because antacids can inhibit absorption of magnesium.
  • Individuals who have gastrointestinal conditions. Why? Because of decreased absorption, in diseases like celiac disease or Crohn’s disease, or from increased loss, such as from chronic vomiting and/or diarrhea.
  • Individuals who are elderly. Why? Because of poor absorption, chronic disease, and long-term medication use.

What happens in your body when you are low in magnesium?

What happens if you have a magnesium deficiency? Can you tell by how you feel? Because magnesium is necessary for more than 600 enzyme reactions in the body, its deficiency can be manifest in many different ways.

Magnesium is an essential nutrient for the electrical activity of the heart, dilation of blood vessels, relaxation of skeletal muscles, bronchial relaxation, nerve transmission, modulation of the inflammatory biomarker C-reactive protein, ATP (energy) production, stress reduction, restful sleep, and insulin sensitivity.* If you are low in magnesium, then you might notice symptoms, but many deficiencies are sub-clinical – in other words you can be deficient but have no symptoms.

Some of the following circumstances could be going on in your body if you’re low in magnesium – some silently, others not so much.

  • Poor vitamin D metabolism. As mentioned above, you need magnesium to metabolize vitamin D,4 because the enzymes that activate vitamin D in your liver and kidneys depend on magnesium to function.*
  • Poor bone structure. Even though calcium, vitamin D, and even vitamin K are more recognizable as important bone-support minerals and vitamins, did you know that 50-60 percent of the magnesium in your body is stored in your bones? Magnesium is important for keeping calcium in the bones and out of the soft tissues.*
  • Muscle cramps or twitches. Most of the magnesium not in your bones is stored in your muscles and other soft tissues (only about one percent is floating around in your bloodstream). Because magnesium is needed to make your muscle fibers relax, if you’re low in magnesium, then your muscles can be the first to tell you so by easily cramping or twitching.*
  • Irregular heartbeat. Remember, your heart is also a muscle. When calcium flows into the cells of your heart, it causes these cells to contract. Then magnesium comes along and tells these cells to relax. Thus, if you’re low in magnesium, you could have an irregular heartbeat.*
  • Poor blood vessel function. Just like magnesium helps your skeletal muscles and your heart muscle relax, it also helps the smooth muscles in the walls of your arteries relax, which helps maintain healthy blood flow and blood pressure.*
  • Inadequate sugar metabolism. Magnesium is necessary for insulin to function properly.* Because the cell receptors where insulin docks when it escorts sugar from the bloodstream into the cells require magnesium to work, magnesium is important for insulin sensitivity and maintenance of healthy blood sugar levels.*
  • Irritability, moodiness, anxious feelings. Because magnesium is an important co-factor for so many enzymes and neurotransmitters, it’s not surprising that low levels can leave you feeling less than cheerful, relaxed, and centered.*  For example, magnesium is important for GABA, a neurotransmitter in the brain that modulates stress responses, and serotonin, which is needed for a good mood and restful sleep.*
  • Low energy. ATP, the energy powerhouses in all cells, needs to bind to magnesium to be active.*

Because magnesium is involved in at least 600 different enzyme reactions in the body, the foregoing is but a glimpse into what might be going on in your body if you have an inadequate level of magnesium.

Stay tuned for part 2, which will explore the potential health benefits of maintaining a healthy magnesium level and how you can accomplish that with diet and supplementation.


  1. World Health Organization. Calcium and Magnesium in Drinking Water: Public health significance. Geneva: World Health Organization Press; 2009.
  2. Grober U. Magnesium and drugs. Int J Mol Sci 2019;20(9):2094.
  3. Magnesium fact sheet for health professionals. [Accessed Oct. 31, 2019]
  4. Uwitonze A, Razzaque M. The role of magnesium in vitamin D activation and function. J Am Osteopath Assoc 2018;118(3):181-189.
  5. Jahnen-Dechent W, Ketteler M. Magnesium basics. Clin Kidney J 2012;5(Suppl):i3-i14.