The intake is balanced by losses in urine and feces. The blood levels of calcium and its intestinal absorption, deposition, or mobilization from bone are all controlled by a complex interplay of vitamin D, parathyroid hormone, and calcitonin. Contrary to some long-held beliefs, high intakes of protein and phosphorus do not lead to a loss of calcium. 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. Folic Acid Chemically, folic acid is pteroylglutamic acid. Nucleic acid synthesis cannot take place without the presence of folic acid. Deficiency in humans results in various anemia and can be produced by antivitamins such as methotrexate, which is used in cancer chemotherapy. Deficiency is relatively rare unless caused by an antivitamin, tropical sprue, or pregnancy.