ABSTRACT
Magnesium is the second-most abundant intracellular cation after potassium. It is one of the four major cations handled by the kidney, the others being sodium, potassium, and calcium. It plays an important role in intracellular signaling, serving as a co-factor for enzymes involved with protein synthesis and DNA production, and maintaining membrane potential in myocytes, especially of the heart, and bone density. The nutritional recommended daily allowance is 300 mg for women and 400 mg for men. Spinach has the highest magnesium content. Other good sources of magnesium are chard, pumpkin seeds, yogurt, nuts, cocoa and banana. The intestine absorbs 30%–40% of ingested magnesium, but it can vary from 24% to 75% depending on the magnesium body content. A higher percentage of magnesium is absorbed in magnesium-depleted diets, and a lower percentage in areas with magnesium-rich foods. The stomach does not participate in magnesium absorption but almost the entire intestine is capable of absorbing magnesium.
