Heavy users of antacids and calcium supplements may be inadvertently poisoning themselves with trace metals, reports Reader's Digest.

University of Illinois toxicologist Dr. Badi Boulos found low levels of manganese, lead, cadmium, aluminum, copper and arsenic in several brands of nonprescription antacids and calcium supplements.Healthy people taking one or two tablets a day are not at risk. However, people taking 10 to 15 tablets a day to try to block osteoporosis - bone deterioration - may experience tremors, psychiatric disorders and neurological symptoms that resemble Parkinson's disease. People with malfunctioning kidneys or gastrointestinal disorders are especially vulnerable.