Magnesium

• In the human body most magnesium is stored in the skeleton followed by the muscle tissues.
• Critical to many cellular functions, such as energy production and cell replication. Controls the activity of over 300 enzymes of the carbohydrate, lipid and protein metabolism. As an example, there are five Mg²⁺-dependent reactions out of 10 in the glycolysis pathway. Mg²⁺ is also an activator of pyruvate dehydrogenase phosphatase (1) and an inhibitor of pyruvate dehydrogenase kinase of pyruvate dehydrogenase multienzyme complex.
• Modulates activity of the ATP-dependent sodium and potassium pump that ensures the right distribution of these ions between the intra- and extracellular compartments of all animal cells. In nerve cells this balance is crucial to the proper flow of the electrical impulses along the nerve.
• Modulates intracellular Ca²⁺ in vascular smooth muscle cells (2). Earlier studies suggested a relationship between low plasma Mg²⁺ concentration and hypertension and heart disease (3).
• Involved in the regulation of calcium metabolism through its action on the parathyroid hormone (stimulates calcium uptake from bone, kidney and intestine) and calcitonin (a thyroid hormone that inhibits calcium uptake from bone and kidney). Helps prevent calcium deposits in kidneys and gall bladder.
• Involved in the proper function of the gastrointestinal tract (4).
• Known also for its antioxidant activity. As shown in animal studies magnesium deficiency led to increased production of reactive oxygen species (ROS). Mg²⁺-deficient rats exhibited increased levels of plasma NO^. (5). NO^. reacts with O₂^- to generate ONOO^-, which can decompose into other more reactive species that can lead to oxidative damage. These findings provide additional support to earlier results that link magnesium deficiency to inflammation and oxidative stress. Moderate Mg deficiency through exarcerbating chronic inflammatory stress may be contributing significantly to the occurence of chronic diseases such as CVD, hypertension, osteoporosis, diabetes and cancer (6).
• Interactions: Magnesium interacts with calcium and vitamin K. It works with vitamins B1, B2 and B6 in many enzyme systems. Higher calcium and zinc intakes decrease magnesium absorption. Some drugs, e.g. diuretics and digitalis adversely affect magnesium status. Intense physical activity requires a higher magnesium intake. High alcohol, tea and coffee consumption decrease magnesium absorption.
• Best food sources: Kelp, tofu, seeds, nuts, whole grains, green leafy vegetables, corn, avocado, garlic, fresh green peas, sweet potato, blackberries, broccoli florets, cheddar cheese, cauliflower, carrots, white fish, celery, chicken, asparagus, stewing beef, potatoes, tomatoes, oranges, whole milk, eggs, black-eyed peas, lima beans.