Magnesium is a mineral that’s crucial to the body’s function. Magnesium is an essential mineral required by the body for maintaining normal muscle and nerve function, keeping a healthy immune system, maintaining heart rhythm, and building strong bones. Magnesium is also involved in at least 300 biochemical reactions in the body. A deficiency in magnesium can lead to muscle spasms, cardiovascular disease, diabetes, high blood pressure, anxiety disorders, migraines, osteoporosis, and cerebral infarction. Conversely, consuming too much magnesium typically causes diarrhea as the body attempts to excrete the excess. The current DV for magnesium is 400mg.
American diets frequently fail to contain an adequate supply of magnesium. In fact, adults average only 66% of the Daily Value (DV) for magnesium from their food intake (even though they get another 8% from supplements). This average intake level leaves U.S. adults about 100-125 milligrams short in the magnesium department. A likely reason for this deficient magnesium intake is the tendency of American diets to focus predominantly on heavily processed convenience foods at the expense of the green leafy vegetables, nuts and seeds, and legumes that are among our best food sources of the mineral.
A study recently published in the American Journal of Clinical Nutrition found that for every 100-milligram (mg) increase in magnesium intake, a person’s risk of developing colorectal cancer drops by about 13 percent.
Create and Maintain Bone Integrity
About 50 to 60% of a person’s magnesium is stored in the bone, and as such, it plays a key role in bone metabolism. Researchers have found that even a mild ongoing magnesium deficiency can lead to a significant amount of bone loss.
Part of the way that this occurs is that when magnesium intake goes too low, levels of parathyroid hormone go down. This leads to a reduced absorption of calcium in the intestines, as well as increased loss of calcium and magnesium in the urine.
A link between adequate magnesium intake and improvements in bone mineral density has been established throughout the life cycle from adolescents all the way to elderly men and women. Researchers have also been able to induce osteoporosis in animal studies through low-magnesium diets&mash;diets that would be similar (at least with respect to %DV intake) to the routine low-grade magnesium-deficient diets humans commonly eat.
We do not know yet whether dietary magnesium has the same level of relative importance as vitamin D or calcium in the maintenance of bone. But the existing research, together with the frequency of magnesium-deficient diets, suggests that low magnesium may be an underappreciated contributor to bone loss.
Enable Energy Production
One critical task performed by our cells is energy production. This task is a complicated one and involves dozens of chemical reactions, all intimately related and flowing in a very special sequence. Unless these chemical reactions can take place in the exact needed order, we don’t get the energy production that we need from our cells. Within this energy production sequence, magnesium plays an important role. Many of the chemical reactions cannot take place unless magnesium is present as “co-factor” for the enzymes that allow energy production to occur. Enzymes are protein molecules that make it easier for chemical reactions to occur throughout the body, including chemical reactions related to energy production. Co-factors are nutrients that must be coupled together with enzymes in order for those enzymes to function.
Based on its role in energy production within our cells, low magnesium levels can be one of the potential contributory factors causing fatigue. Because magnesium deficiency is hard to test via blood work or equivalent laboratory testing, it is not clear what percentage fatigue symptoms are caused or contributed to by magnesium. However, if you look at changes in fatigue symptoms from studies in which participants were given magnesium supplements at levels at least as high as the Recommended Dietary Allowance (RDA) and you couple these study results with information we already know about low intake of magnesium by the average U.S. adult you can draw a conclusion that low dietary intake of magnesium increases our risk of fatigue.
Maintain Nervous System Balance
Receptors are special molecules along our cell membranes that help chemical messages enter and leave our cells. All of the cells in our body have membrane receptors. Among the best studied are receptors found along the membranes of our brain cells. One of these brain cell receptors is referred to as the NMDA receptor. (NMDA stands for N-methyl-d-aspartate.) The NMDA receptor is noted for being the site where some anesthetics and recreational drugs affect our brain function.
Magnesium plays a key role in the activity of our NMDA receptors. Research studies have shown that when magnesium in our diet is low, we have increased risk of depression, and this increased risk is likely related to problems with our NMDA receptors. A long history of published evidence demonstrating that treatment with magnesium can have anti-depressant effect this was first published in 1921 suggests that low magnesium can actually cause depression.
Better Control of Inflammation
A diet low in magnesium has been linked to unwanted increases in the inflammatory process. While some amount of inflammation is necessary to support normal immune function and tissue repair after injury, chronic and low-grade inflammation has increasingly been tied to increased risk of heart disease, obesity, and diabetes.
Restoring magnesium levels to recommended intakes has led to normalization of inflammation in clinical trial settings. For example, one large clinical trial found that a Nordic diet strategy a diet rich in fish, whole grains, and vegetables as sources of magnesium led to a suppression of the important inflammatory trigger interleukin-1.
Better Control of Blood Sugar
Magnesium is a co-factor for over 100 enzymes involved in the control of blood sugar and glucose metabolism. As such, low magnesium status would be expected to have wide-ranging adverse effects on blood sugar control. Researchers have been able both to demonstrate worsening blood sugar control in individuals with low magnesium status and improvements in blood sugar when these low levels begin to normalize. We address this subject in more detail in the section entitled Factors that Affect Function.
There’s some evidence that eating foods high in magnesium and other minerals can help prevent high blood pressure in people with prehypertension.
Intravenous or injected magnesium is used to treat other conditions, such as eclampsia during pregnancy and severe asthma attacks. Magnesium is also the main ingredient in many antacids and laxatives.
Severe magnesium deficiencies are rare. They’re more likely in people who:
- Have kidney disease
- Have Crohn’s disease or other conditions that affect digestion
- Have parathyroid problems
- Take antibiotics or drugs for diabetes and cancer
- Are older adults
- Abuse alcohol
- Health care providers sometimes suggest that people with these conditions take magnesium supplements.
Proton pump inhibitors (PPIs) a common type of medicine used to treat acid reflux, have also been tied to low magnesium levels.
Natural sources of Magnesium
- Dark Leafy Greens (Raw Spinach) Magnesium in 100g 79mg (20% DV)
- Nuts and Seeds (Squash and Pumpkin Seeds) Magnesium in 100g 534mg (134% DV)
- Fish (Mackerel) Magnesium in 100g 97mg (24% DV)
- Beans and Lentils (Soy Beans) Magnesium in 100g 86mg (22% DV)
- Whole Grains (Brown Rice) Magnesium in 100g 44mg (11% DV)
- Avocados Magnesium in 100g 29mg (7% DV)
- Low-Fat Dairy (Plain Non Fat Yogurt) Magnesium in 100g 19mg (5% DV)
- Bananas Magnesium in 100g 27mg (7% DV)
- Dried Fruit (Figs) Magnesium in 100g 68mg (17% DV)
- Dark Chocolate Magnesium in 100g 327mg (82% DV)
Risks of taking magnesium
Side effects. Magnesium supplements can cause nausea, cramps, and diarrhea. Magnesium supplements often cause softening of stool.
Interactions. Magnesium supplements may not be safe for people who take diuretics, heart medicines, or antibiotics. Check with your health care provider if you are taking any medicine before taking magnesium.
Risks. People with diabetes, intestinal disease, heart disease or kidney disease should not take magnesium before speaking with their health care provider.
Overdose. Signs of a magnesium overdose can include nausea, diarrhea, low blood pressure, muscle weakness, and fatigue. At very high doses, magnesium can be fatal.