It also regulates nervous excitability and muscle contraction and may be protective against high blood pressure. During periods of growth, pregnancy, and lactation, calcium intake should be increased. Diseases of calcium metabolism include vitamin D deficiency, hypervitaminosis D, hypo- and hyperparathyroidism, and some forms of renal disease. Magnesium is an essential element in human metabolism and functions in the activities of muscles and nerves, protein synthesis, and many other reactions. Magnesium deficiency may occur in alcoholism, diabetes mellitus, pancreatitis, and renal diseases.
Prolonged deficiency can cause changes in heart and skeletal muscle.
Excessive retention of magnesium can occur in renal disease and results in muscle weakness and hypertension. This board is composed of distinguished scientists and nutritionists and is under the auspices of the National Academy of Sciences. These allowances are intended as a guide for all persons involved in planning food supplies and in the interpretation of food consumption levels.