Q: I am 27 years old, married and expecting my first child this coming July. When I saw our OBGYN doctor two weeks ago, I was prescribed a prenatal vitamin. I’ve been taking it once daily as directed but have had a great deal of constipation and want to stop it.

When I called the doctor’s office to explain this, the nurse said it was important to continue it, even though I’ve had a rather long-standing problem with constipation. How important is the vitamin, and are there any alternatives?

A: It is very important, but there are several alternatives. The vitamin is important — particularly to your fetus. Prenatal vitamins contain folic acid, which has been well-demonstrated to prevent the occurrence of anencephaly, a birth defect that is nearly always fatal to the baby. Babies with anencephaly usually die within a few days of birth. Babies that might survive longer are never able to care for themselves.

This defect is a result of the failure of closure of the neural tube during gestation. This process begins at the bottom of the spine and progresses toward the head and results in the folding inward of the spinal cord and skull, so that the entire central nervous system is enclosed and protected from injury or infection. I recommend Googling the term “anencephaly” to learn more about this problem and see pictures of babies with this defect.

The usual folic acid dose in prenatal vitamins is 1 mg, or 1,000 micrograms (mcg). Folic acid in this dose is not available over the counter and thus requires a prescription. A viable alternative is the 400-mcg dose of folic acid, which is available without a prescription, though you would probably require the assistance of the pharmacist to locate it in the store. To reach a clinically effective dose, this should be taken twice daily, and there are virtually no adverse effects.

Secondarily, your worsening constipation is undoubtedly caused by the iron in the vitamin, of which most Americans (who are not on a purely fast-food diet) generally receive enough in their daily diet. Other alternatives to enhance iron intake include mainly green leafy vegetables.

I want to thank Courtney R. for this question. To learn more about this and many other health topics, visit the American Academy of Family Physicians’ website, familydoctor. org. If you have a topic you would like to hear more about, please message me at paulmdake@gmail.com.

Dr. Paul Dake, a Newberry native, is a retired family physician. He lives in Pinconning, Michigan.