Deficient in alcoholics. Excessive intake can lead to deficiencies of other elements. Abdominal pain, anorexia, diarrhea, irregular heartbeat, mood swings, nausea, weakness, painful urination, vomiting. If you have kidney or heart problems, do not take magnesium supplements without consulting a doctor. Cellulose sodium phosphate decreases magnesium's effectiveness.
Magnesium reduces the absorption of ketoconazole and tetracycline.
Magnesium can slow the urinary excretion of mecamylamine. Vitamin D can increase magnesium concentrations in the body. Do not take magnesium supplements during pregnancy or nursing without the advice of your health care professional.