Is it OK if I take prenatal vitamins even if I'm not pregnant? And if I do take them, will it increase the possibility of getting pregnant?

April

While taking a prenatal vitamin will do nothing to help you conceive, there are still reasons for many women to take them whether or not they are planning a pregnancy. They certainly will not cause any harm, and there may, in fact, be many advantages to taking a prenatal vitamin rather than a simple multivitamin.

While there are many different types of prenatal vitamins that differ in their composition, the main characteristic of the prenatal vitamin is the availability of extra folic acid. Most of us have diets that leave us relatively deficient in folic acid. Genetic differences in an enzyme called MTHFR affect how our bodies use folic acid. This means that some of us require more folic acid than others to maintain optimal health. Most OBs recommend 1mg of folic acid daily during pregnancy.

So why is folic acid so important? Studies have linked folic acid deficiency to various fetal anomalies. In particular, defects in the formation of the nervous system, spina bifida, anencephaly and other abnormalities of neural tube development may be increased in babies carried by women deficient in folic acid.

Folic acid is also an important promoter of the body's processing of a substance called homocystine. High levels of homocystine in the blood have been linked to cardiovascular disease and hypertension. Folic acid encourages the body to convert homocystine into compounds that help the blood vessels relax and protect the blood vessels' inner lining from damage by free-oxygen radicals. Men who suffer from cardiovascular disease generally have lower levels of folic acid.

In addition, folic acid is required for the production of serotonin, an important neurotransmitter (chemical messenger) that has been connected to mood. Folic acid levels appear to be lower in women suffering from depression.

So in addition to lowering your odds of certain birth defects in pregnancy, the folic acid in prenatal vitamins may reduce the potential for heart disease and depression. This seems wonderful. Is there a down side to taking these vitamins? I guess so. Many women say they experience nausea from prenatal vitamins. Gastrointestinal upset is often due to the iron and/or calcium incorporated into the prenatal vitamin. If switching brands does not alleviate the nausea, these women would do well to ask their doctors if they should take a separate 1mg folic acid tablet.

While it seems a good idea to put everything you need into one pill, that may not really such a good idea. Often the iron and the calcium in the pill will bind together, and each will diminish the absorption of the other. Choosing a separate iron or calcium supplement to be taken at a separate time may avoid this problem.

Also, check with your physician to determine if the prenatal vitamin will interact with other medications you are taking. A common interaction occurs between prenatal vitamins and the thyroid hormone Synthroid. The interaction often lessens the body's ability to absorb Synthroid, often requiring an adjustment of the dose.