By Howard LeWine, M.D.
Q: I’m hoping to get pregnant later this year. I consider my diet to be well balanced. Do I also need additional vitamins?
A: It’s terrific that you’re thinking about how to have a healthy baby before you become pregnant. Eating a diet loaded with fruits, vegetables and healthy grains is a great start. But you also want to take supplemental folic acid every day starting now.
Daily folic acid supplementation starting at least one month prior to conception and continued for the first three months of pregnancy greatly reduces the risk of neural tube defects. Neural tube defects are a type of developmental abnormality of the nervous system, such as spina bifida.
Taking folic acid prior to pregnancy may have additional benefits. One study looked at 35,000 pregnancies. Some women said they took folic acid pills for at least a year before they got pregnant. These women had only half the average risk of premature birth.
A different study done in Canada included more than one million newborns. The study found that heart defects in babies have been less common since Canada started adding folic acid to some foods.
Every woman who has any chance of becoming pregnant should take extra folic acid. The dose should be at least 400 micrograms per day. That’s the amount in a standard multiple vitamin.
For women who are trying to become pregnant, 800 micrograms is safe. It also may be slightly better at preventing spina bifida and other birth defects.
Women who’ve ever been pregnant with a baby affected by a neural tube defect should take a much higher dose. The U.S. Centers for Disease Control and Prevention recommends 4,000 micrograms per day for these women. They should begin taking this higher dose at least a month before conception. They should continue the same high dose throughout the first three months of pregnancy.
You also want to be sure your iron intake is adequate. I recommend women considering pregnancy take one multiple vitamin with iron and a 400-microgram folic acid supplement, for a total of 800 micrograms daily. If you have heavy menstrual periods or have ever been slightly anemic, ask your doctor if you should take an iron supplement, as well.
(Howard LeWine, M.D., is an assistant professor of medicine at Harvard Medical School.)
(For additional consumer health information, please visit www.health.harvard.edu.)