Magnesium, a mineral, is used in building bones and making proteins. It is the 4th most abundant mineral in the body. 50% is found in the bone. The other half is in cells in tissues and organs. Mg also aids in releasing energy from muscle storage and regulating body temperature. USDA studies show that most women get less than the Recommended Daily Allowance (RDA).

The established RDA for Mg is unclear. Some studies say it should be 400 milligrams (mg) per day for adults, except pregnant or lactating women, which is less. Other studies say RDA should be 280 mg. for women. Still others suggest RDA to be 2 mg. per pound body weight. The typical American diet provides less than this, yet almost four times more calcium than magnesium. Using 2 mg per lb. body weight, a 120 lb. female would only need 240 mg of magnesium. Many experts believe the optimal range should be 2.7 – 4.5 mg. per pound. Magnesium researchers recommend up to 1000 mg per day for healthy people. Diarrhea may be a symptom of too much or too little Mg.

Healthy persons if they get a balanced diet rarely need supplements. Most people don’t get a balanced diet. Mg is found in wheat germ and wheat bran, vegetables such as artichokes, lima beans, soybeans, broccoli, chard, and spinach. It is also in meat, poultry and fish, nuts, fruit, and hard water. 50% of Mg can be lost in cooking. (To retain Mg, foods should be cooked in a small amount of water and for the shortest possible time.) Soda or pop decreases the body’s absorption of Mg in the intestines. The phosphoric acid in soda combines with Mg to form insoluble magnesium phosphate that is excreted through the feces.

Too much supplemental calcium to prevent osteoporosis in adults can lead to less magnesium absorption. Some studies link cardiovascular diseases to magnesium depletion. It is important to get the right amount of calcium and magnesium. A dietary program for primary postmenopausal osteoporosis should include both magnesium and calcium for preventing bone loss. (Bone loss caused by excessive steroids, immobilization, or weightlessness is termed secondary osteoporosis.) A number of calcium supplements on the market include Mg.

Magnesium has been recommended for healthy people as well as for those with osteoporosis, cardiovascular disease, depression, diabetes, chronic fatigue syndrome, premenstrual syndrome, and hypertension. Predisposing factors and symptoms should be evaluated before taking magnesium. The correct amount for you should be discussed with your rheumatologist, gynecologist, endocrinologist, or primary care physician.

Not having enough Mg can be associated with abnormal heartbeats and EKG changes. Not enough Mg. may also be linked to nerve symptoms like muscle twitching and motor nerve irritability, or seizures in children. Causes of low Mg might include diarrhea, chronic diarrhea, diuretic use, heavy alcohol use, and poor kidney function. When there is low magnesium often there is also low potassium. Low potassium levels are seen in 40-60% of people with low magnesium levels.

Signs of too much Mg can be similar to too little. These signs include changes in mental status, nausea, diarrhea, appetite loss, muscle weakness, difficulty breathing, extremely low blood pressure and irregular heartbeat.

Supplements should be taken in the early part or middle of a larger meal to avoid stomach problems and promote better tolerance. When taken on an empty stomach or after a meal there is greater risk of some tablets causing irritation. It is also best not to lie down immediately after taking any pills.

When taking a large amount of a nutrient, it is better to split it into smaller doses so it won’t interfere with the absorption of other nutrients in food or nutrients that are being supplemented at lower amounts.

Learn more about magnesium from the Office of Dietary Supplements, National Institutes of Health.

Top of Page