Magnesium is an essential mineral that has a hand in many vital body functions, for example releasing energy, regulating body temperature, building protein, and stabilizing bone. It is also one of several nutrients that helps keep blood pressure within a healthy range. And since magnesium is plentiful in vegetables, legumes, and whole grains, it is easy to consume enough if you are eating healthy food.
Functions
Magnesium's functions include:
- Activating more than 300 enzymes (Enzymes are chemicals that regulate a variety of body functions, including making body proteins and causing muscle contractions.)
- Aiding in the metabolism of fat and carbohydrate to produce energy
- Binding with ATP to form "active ATP," which provides energy for almost all metabolic reactions and processes
- Ensuring proper nerve and muscle function and keeping heart rhythm steady
- Helping synthesize nucleic acids (DNA and RNA) and proteins, which are the building blocks of body tissue
- Giving structure to cell membranes
- Helping keep bones healthy
- Decreasing the risk of tooth decay by binding calcium to tooth enamel
Recommended Intake
| Age Group |
Recommended Dietary Allowance
(mg/d) | |
|---|---|---|
| Male | Female | |
| 0-6 months |
Adequate intake
(AI) = 30 | AI = 30 |
| 7-12 months | AI = 75 | AI = 75 |
| 1-3 years | 80 | 80 |
| 4-8 years | 130 | 130 |
| 9-13 years | 240 | 240 |
| 14-18 years | 410 | 360 |
| 19-30 years | 400 | 310 |
| 31-50 years | 420 | 320 |
| 50-70 years | 420 | 320 |
| >70 years | 420 | 320 |
| Pregnancy (18 years or younger) | n/a | 400 |
| Pregnancy 19-30 years | n/a | 350 |
| Pregnancy 31-50 years | n/a | 360 |
| Lactation (18 years or younger) | n/a | 360 |
| Lactation 19-30 years | n/a | 310 |
| Lactation 31-50 years | n/a | 320 |
Magnesium Deficiency
Magnesium deficiency is rare because most people have large stores of this mineral in their body. However, it can be caused by diseases or medicines that interfere with the body's ability to absorb magnesium. Symptoms of a magnesium deficiency include: irregular heartbeat, nausea, confusion, depression, tingling, weakness, loss of appetite, and muscle contractions and cramps.
Conditions and medicines that may lead to a magnesium deficiency include:
-
Gastrointestinal disorders, such as:
- Severe diarrhea
- Chronic or severe vomiting
- Surgical removal of part of the intestine
- Intestinal inflammation
- Malabsorption disorders
, including:
- Crohn’s disease
- Cystic fibrosis
- Celiac disease
- Diseases of the pancreas, liver, or gallbladder
- Thiazide diuretics (can increase loss of magnesium in the urine)
- Cisplatin (a drug used to treat cancer)
- Certain antibiotics, including gentamicin , amphotericin, and cyclosporin
- Poorly controlled diabetes (can increase the loss of magnesium through urine)
- Alcoholism—Alcohol increases urinary excretion of magnesium. People who drink heavily typically have poor diets that are lacking in many essential nutrients, including magnesium.
- Kidney disease—The kidneys are important for reabsorption and excretion of magnesium.
Tolerable Upper Intake
It's also possible to get too much magnesium. The Office of Dietary Supplements publishes tolerable upper intake levels for magnesium.
| Age Group |
Tolerable Upper Intake Levels
(mg/d) | |
|---|---|---|
| Male | Female | |
| 1-3 years | 65 | 65 |
| 4-8 years | 110 | 110 |
| 9-18 years | 350 | 350 |
| 19+ years | 350 | 350 |
| Pregnancy (18 years or younger) | n/a | 350 |
| Pregnancy 19+ | n/a | 350 |
Magnesium Toxicity
Magnesium toxicity through food intake is not a concern for most healthy people. However, people with kidney disease may develop toxicity because the kidneys are responsible for regulating the level of magnesium in the blood. Also it is possible to take too much magnesium in supplements. Symptoms of magnesium toxicity include:
- Diarrhea
- Abdominal cramping
- Nausea and diarrhea
- muscle weakness
- irregular heartbeat
Major Food Sources
Magnesium is found in a variety of foods. The best sources are legumes, nuts, whole grains, and certain vegetables. "Hard" water (which is high in dissolved minerals, specifically calcium and magnesium) is also a source of magnesium.
Foods that provide high levels of magnesium include:
- Wheat bran
- Almonds <

