Can a person overdose on vitamin D?

Yes, a person can take too much vitamin D. It is important to not take more than the recommended dosage of vitamin D, since it can build up in the system. Some early symptoms of an overdose are bone pain, increased thirst, diarrhea, headache, muscle pain, nausea, dry mouth, constipation, irregular heartbeat, itching skin, loss of appetite, increase in urination, and unusual tiredness or weakness. If high levels exist in the body, it can result in poisoning or even the possibility of death.