Excessive use of vitamin D can potentially lead to vitamin D toxicity. Early symptoms of vitamin D toxicity are loss of appetite, and may even include anorexia, irritability, crying, and low fever. Some patients may also experience excessive sweating, nausea, vomiting, diarrhea, and constipation. Older individuals may present with headache, elevated or decreased blood pressure, systolic murmurs may be heard in the heart, and mild anemia may also be present. Severe cases may present with depression, hypotonia, dyskinesia, and even coma, convulsions, and renal failure. Long-term chronic poisoning may lead to corresponding calcification of bones, kidneys, blood vessels, and skin, affecting the physical and intellectual development of patients, and in severe cases, death may result from renal failure.