We hear all the time about the importance of certain nutrients for health and wellness:
Calcium for bones
Fish oil for the heart
Vitamin C for the immune system
One nutrient that often flies under the radar is magnesium. This is a big problem because surveys show that more than 50 percent of people worldwide have subclinical magnesium deficiency. According to a new review in the British Medical Journal, lack of magnesium increases risk of a number of diseases including cardiovascular disease, high blood pressure, osteoporosis, and type 2 diabetes. Other ill effects include poor recovery from intense exercise, trouble sleeping, depression, difficulty coping with stress, anxiety, and hormone imbalances (for example, low testosterone in men).
This article will cover the role of magnesium in the human body, discuss risk of deficiency, and provide guidelines for restoring levels.
Why Do Humans Need Magnesium?
Magnesium has several actions in the human body:
It is necessary for the functioning of over 300 enzymes. Enzymes are important because they allow for chemical reactions to take place, including protein synthesis, digestion, and the production of ATP for energy, to name a few.
A primary target of magnesium is the cardiovascular system. Magnesium has a calming effect on the heart and blood vessels, lowering heart rate and allowing for more flexibility in the vascular system.
Magnesium calms the central nervous system, reducing depression and lowering insomnia.
Magnesium improves balance of steroid hormones like testosterone and cortisol.
Magnesium works with calcium and vitamin D for the prevention of osteoporosis. Magnesium activates cellular enzyme activity, allowing the body to convert vitamin D into the active form to help with calcium absorption and bone building.
Magnesium plays a role in blood sugar regulation, helping the storage hormone insulin to bind with cell receptors. Magnesium also increases expression of GLUT 1 and 4, which are molecules that act like buses, shuttling glucose into your cells so that they can be used for energy.
Magnesium impacts digestion and researchers suggest the beneficial effect of dietary fiber on the GI tract is due to its high magnesium content.
Magnesium plays a role in muscle contractions and is associated with strength, especially in older adults who are at risk of losing strength and muscle.
Are You At Risk Of Deficiency?
There are two types of nutrient deficiencies:
Frank deficiencies have obvious symptoms. Examples include scurvy from lack of vitamin C or goiter from lack of iodine. These are generally straightforward to diagnose.
Subclinical deficiencies occur when there is a clinically silent reduction in physiological, cellular, or biochemical function. These may have negative or variable health effects that are not so apparent. An example is vascular calcification (hardening of the blood vessels) that leads to high blood pressure and heart disease.
When it comes to magnesium, a subclinical deficiency is what we are most concerned with because it is hard to diagnose and predisposes to chronic disease. For example, less than 50 percent of the U.S. population is meeting the U.S. RDA of 300 to 420 mg a day. The average magnesium intake for women is 228 mg and for men it is 323 mg a day (this equals about 4 mg/kg) meaning that a substantial number of people are at risk of deficiency especially if they experience concomitant disorders or medications that increase risk of depletion. Surveys around the world show similar deficiency rates in developed countries including Japan, Taiwan, France, and Germany.
Why Is Magnesium Deficiency A Problem?
Magnesium intake has decreased since 1900 when surveys show the average person consumed more than 400 mg a day. This is due to several factors:
There has been a significant reduction of magnesium in food and soil. One report found a 35 percent decrease in magnesium in vegetables.
The Western diet is deficient in foods containing magnesium. Processing strips ingredients of magnesium. For example, one study found that 82 percent of magnesium is lost from white flour, 83 percent from polished rice, and 99 percent from sugar. One estimate shows that an American would need to eat more than 3000 calories a day to provide the baseline 300 mg of magnesium.
The standard high-carbohydrate diet used in the developed world raises magnesium needs significantly. Lack of magnesium combined with a high intake of refined carbs is theorized as one reason for the surge in cases of type 2 diabetes cases.
How To Test For Magnesium
One reason magnesium deficiency is hard to identify is that the standard test used by medical doctors for magnesium measures serum magnesium levels in the blood. Only about one percent of magnesium is found in the blood and the rest is in bone and muscle. When serum magnesium levels go down, the body will pull it from bone and muscle, which increases risk of osteoporosis and muscle disorders.
There are several methods for assessing total body magnesium status, but the most common is a red blood cell magnesium test. If this is not a possibility, one group of experts recommends supplementation in individual experiencing symptoms of magnesium deficiency if their serum levels are below 0.9 mmol/L, with levels below 0.8 mmol/L necessitating supplemental magnesium.
How To Bring Your Magnesium Levels Up
For people who are experiencing mild symptoms, supplementation and increasing dietary magnesium may solve the problem. Good sources of magnesium are nuts, dark chocolate, leafy greens, and unrefined whole grains.
When supplementing, it’s recommended to choose a form that as bound with amino acid chelates such as magnesium taurate or magnesium glycinate. Magnesium blends containing multiple forms of magnesium also tend to be well absorbed. Avoid magnesium salts such as the ubiquitous (and cheap) magnesium oxide. One study recommends 10 mg/kg of body weight of magnesium per day.
For people working with a practitioner to solve subclinical magnesium deficiency, experts recommend supplementing with a minimum dose of 600 mg of magnesium per day for a minimum of one month, continuing with that dose until serum levels hold steady at 0.9 mmol/L.
DiNicolantonio, J., et al. Subclinical magnesium deficiency: a principal driver of cardiovascular disease and a public health crisis. British Medical Journal. 2018. 5(1):e000668.
Ford, E., Mokdad, A. Dietary Magnesium Intake in a National Sample of U.S. Adults. Journal of Nutrition. 2003. 133(9);2879-2882.
Nielsen, F.H. Magnesium, Inflammation, and Obesity in Chronic Disease. Nutrition Review. 2010. 68(6), 333- 340.
Schechter, Michael. Magnesium and Cardiovascular System. Magnesium Research. 2010. 23(2), 60-72.
Welch, A., et al. Dietary Magnesium May Be Protective for Aging of Bone and Skeletal Muscle in Middle and Younger Older Age Men and Women: Cross-Sectional Findings from the UK Biobank Cohort. Nutrients. 2017. 9(11).