Functions of Magnesium
Magnesium is often a neglected nutrient. Low intakes are common and are associated with cardiovascular disease, type 2 diabetes, and osteoporosis. Along with an adequate intake of potassium and calcium, these minerals favor a lower risk of hypertension.
50 to 60% of magnesium in the body is found in bone. The rest resides inside the body cells with a small percentage in the blood. It functions in over 300 enzyme systems, many of which involve the release of energy, proper functioning of nerves and muscles including those of the heart and in the many steps of DNA, RNA and protein synthesis. It also affects the metabolism of calcium, sodium and potassium.
How Much Do We Need?
The Recommended Dietary Intake (RDI) is 400 mg for adults and children over the age of 4. The Upper Tolerable Level (UL) is 350 mg from non-diet sources.
An intake below the RDA is commonly seen in the population but a blatant deficiency is rare. The use of diuretics can increase urinary loss and the use of proton pump inhibitors to treat gastroesophageal reflux disease GERD) can interfere with magnesium absorption.
The best food sources are:
Seeds and nuts
Leafy greens like spinach
Processed foods are poor choices. For example, a cup of whole wheat flour contains about 166 mg. of magnesium. When that grain is refined and thus more processed, the white flour only contains 28 mg.
Since magnesium is not found abundantly in many foods, magnesium supplementation is popular and claimed to be beneficial for just about any disorder.
Research on the role of magnesium in other medical conditions is sparse. For example, magnesium levels in the body may alleviate the effects of osteoporosis. Dietary magnesium may have some benefit, but using supplements does not appear to have the same effect. The same may be true for its role in controlling hypertension. Its claims often include treating anxiety, ADHD, depression, and muscle cramps; however, most research does not report much help from supplements. One common side effect of magnesium supplementation is its laxative effect with some forms. Magnesium taurate and magnesium glycinate appear to not have this effect.
Always tell your doctor about any supplements you take. Dietary supplements are not regulated by the FDA, so buyer beware.