James Lind, a physician in the British navy, demonstrated in 1757 that consumption of oranges and lemons could prevent the disease. Chemically, ascorbic acid is a plant sugar in the acid form, hexuronic acid. In the body ascorbic acid is reduced to dehydroascorbic acid and is involved in oxidation-reduction reactions. 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.