I am trying to conceive right now and am wondering about the amount of vitamins I am now taking. I take 1,800mg of calcium, one prescription prenatal vitamin (Nestab), 1,200mg of folic acid, and various B vitamins. Do any of these vitamins build up in a person's system? Is this unhealthy while trying to conceive or during pregnancy? Are there risks from any other vitamins I should be aware of?

Julie

Some vitamins are good for you during pregnancy; for example, folic acid may reduce the risk of some birth defects. However, hypervitaminosis -- excess ingestion of synthetic vitamins -- can cause neurologic problems as well as birth defects. In particular, synthetic vitamin A (taken as supplements as opposed to that ingested in food) can be particularly damaging to the fetus if taken in excess. The high dose of calcium, if taken at the same time as other supplements, may reduce your body's ability to absorb iron, leading to iron deficiency. You are best served by simply taking a prenatal vitamin along with paying proper attention to your diet.