Magnesium is necessary for more than 300 biochemical reactions in the body, from helping with muscle relaxation and nerve conduction to steadying your heart rhythm, supporting your immune system, and keeping your bones strong.

© Ilkajb | Dreamstime.com

Magnesium is an important mineral and nutrient. Your body uses magnesium to regulate functions of your muscles, nerves, blood sugar, and blood pressure. Magnesium is also important for the building bone tissue and proteins. [1]

Magnesium is found in many foods and is added to some breakfast cereal. It is also included in most multivitamins. The recommended daily amount of magnesium depends on your age and sex. For an adult male it is 400 to 420 milligrams (mg) per day, for a woman 310 to 320 mg.

How Common is Low Magnesium?

Low magnesium – magnesium deficiency – is not common. Although many people get less than the recommended amount of magnesium from their diets, the body avoids low levels by decreasing loss of magnesium in the urine and increasing absorption of magnesium from the intestine. The body also stores magnesium in tissue and bones, so low levels can be prevented by using stored magnesium. [2]

Magnesium deficiency can occur if intake of magnesium is low for a long time. Elderly people are at higher risk because they do not absorb magnesium from the diet as well as younger people. Conditions that decrease absorption of magnesium and may lead to deficiency include:

• Crohn’s disease
• Celiac disease
• Long term use of antacids, called proton pump inhibitors
• Alcohol abuse
• Some water pills (diuretics)
• Long-term diarrhea [1-3]

Low Magnesium Symptoms and Treatment

Low magnesium may be suspected by the signs and symptoms it causes. Magnesium deficiency is confirmed by a blood test to check magnesium level in the blood. [3] The earliest symptoms of magnesium deficiency are:

• Loss of appetite
• Nausea and vomiting
• Fatigue
• Weakness [1]

Severe magnesium deficiency can cause tingling and numbness, muscle cramps, seizures, palpitations, and personality changes. [1] If your health care provider diagnoses magnesium deficiency, the usual treatment is taking a magnesium supplement by mouth. If magnesium can’t be taken orally or absorbed, it may be given as an intramuscular or intravenous injection. [3]

Should You Take Magnesium Supplements?

Because magnesium is present in many foods, it is better to get magnesium from your diet than from a supplement. Magnesium supplements can cause side effects and the dose of supplement at which side effects start is close to the recommended daily dose. Side effects can start at supplement doses of 350 mg per day. The best advice is not to take a magnesium supplement unless your health care provider prescribes it for you. Side effects of too much magnesium include:

• Diarrhea
• Nausea
• Cramps
• Irregular heartbeat [1,2]

Benefits from Higher Levels of Magnesium

There have been some studies linking low levels of magnesium to several medical conditions, but few studies have found that adding magnesium consistently improves these conditions. These conditions include osteoporosis, depression, anxiety, high blood pressure, and type 2 diabetes. More research is needed before magnesium supplements can be recommended for treatment of these conditions. [1,2]

Low levels of magnesium have been linked to more frequent migraine headaches. Giving magnesium in doses of 4 to 600 mg may reduce or relieve migraines. However, these high doses may lead to side effects, so they should only be prescribed by a health care provider. Finally, although many people try a magnesium supplement to reduce leg or foot cramps, a review of studies has not found that magnesium supplements help. [2]

How to Get Magnesium From Your Diet

If you have symptoms of low magnesium, especially if you have risk factors for low magnesium, talk to your health care provider. Otherwise, you can get the recommended amount of magnesium from these healthy foods:

• Legumes
• Nuts and Seeds
• Leafy green vegetables
• Whole grains
• Milk and dairy foods
• Yogurt
• Fish, beef, and poultry
• Mango, raisins, and bananas
• Fortified cereals [1,2]

RECOMMENDED FOR YOU

• Do You Have Magnesium Deficiency Symptoms?
• Constipation Remedies Needed? Try Magnesium
• What You Must Know About Low Magnesium Symptoms 
• What is Magnesium Used for?
• Magnesium for Bone Health
• Foods High in Magnesium, the “Miracle Mineral” 

SOURCES

1. NIH, Magnesium – Health Professional Fact Sheet (nih.gov)
2. Harvard School of Public Health, Magnesium | The Nutrition Source | Harvard T.H. Chan School of Public Health
3. Merck Manual, Hypomagnesemia (Low Level of Magnesium in the Blood) – Hormonal and Metabolic Disorders – Merck Manuals Consumer Version