Here is a quick list of what can happen when you overdose on certain vitamins and what to watch out for:

Vitamin A: 100,000 daily can cause irritability, fatigue, insomnia, painful bones and joints, abnormal bone growth, loss of hair, itchy skin, anorexia, decreased blood clotting time, birth defects, and abortions. In children this causes fatigue, abnormal growth, and pain tenderness in the bones, and a headache and irritability.

Vitamin E: can cause a possible raise in blood pressure

Vitamin D: can cause anorexia, nausea, diarrhea, muscle weakness, joint pains, calcification of soft tissues, and re absorption of bone. In children it can cause weakness, lethargy, anorexia, and constipation, and chronic overdosing can cause hypocalcaemia, nephrocalcinosis, and eventually azotemia.

Vitamin K3: may cause vomiting, during pregnancy can cause jaundice in the newborn, block the effects of oral anticoagulants.

These are not the only potential dangers; however the main point here is that you need to be careful not to overdose everything. You can also experience major problems when you mix vitamin supplements with other drugs. That is why you must talk to you doctor before adding any vitamin supplements to your daily dose list. As you can see, too much of a good thing can be hazardous to your health.