Are prenatal vitamins safe for women who aren’t pregnant?

Does anything sound healthier than taking a prenatal vitamin? After all, if the nutrients in it are good enough to benefit a developing human, how could they not work the same way for a full-fledged one? Plus, it can deliver all the hair and nail strengthening benefits mothers-to-be enjoy throughout pregnancy.

But experts warn that you can have too much of a good thing. And a prenatal vitamin has too many nutrients for someone who’s only supplementing for one.

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“Pregnancy is a period of intense fetal growth and development, as well as maternal physiological change, so adequate intake of macronutrients and micronutrients during pregnancy promotes these processes,” says Dr. Ahmed Shahata, chief resident of obstetrics and gynecology at Kingston General Hospital. “Undernutrition and overnutrition can be associated with adverse pregnancy outcomes.”

While it’s recommended that women who are trying to conceive should start taking a prenatal vitamin roughly 12 weeks before pregnancy, the elevated levels of calcium, iron and folic acid aren’t suited for a person who isn’t pregnant or preparing to be.

“If you look at the amount of folic acid, iron, calcium and even vitamins A, C and E in a prenatal vitamin compared to a multivitamin, you’ll see that they’re very different amounts,” says Dr. Daniela Caprara, staff OBGYN at Humber River Hospital. “If you’re taking in more nutrients than are recommended per day, it could increase toxicities.”

The three crucial ingredients in a prenatal vitamin — folic acid, iron and calcium — all play a distinct role in women who are pregnant, trying to conceive or breastfeeding. Folic acid is important to prevent neural tube defects in the developing fetus, iron is needed for fetal development and to expand the woman’s red blood cell mass, while calcium has been shown to reduce the risk of developing a hypertensive disorder in pregnancy.

An excess intake of these supplements in someone who isn’t pregnant, however, could have adverse effects.

Caprara says excess iron could cause constipation, diarrhea or nausea, and too much vitamin A could increase liver toxicity. If you don’t naturally metabolize calcium, too much intake could increase the development of gall bladder or renal stones. And Shahata points out that excessive vitamin E intake has been linked to strokes.

In addition, while the body does a good job of naturally flushing out excess folic acid, taking in too much of it runs the risk of masking a vitamin B12 deficiency. Should that happen, you can be more susceptible to an endocrine-related autoimmune disorder like diabetes or thyroid disease.

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Other complications of a B12 deficiency include the development of neurological issues, like problems with balance and persistent tingling in the hands and feet. It can also lead to mental confusion and forgetfulness.

In light of this, experts recommend that you opt for a multivitamin instead of a prenatal one if you’re looking to boost your nutrients but not looking to conceive.

“You should be getting most of your nutrients from your diet, but it’s OK to supplement that,” Caprara says. “Theoretically, you’re taking more than you need if you’re taking a prenatal vitamin. You have to look at the risks versus the benefits to your body. A regular multivitamin is definitely better for a non-pregnant female.”

If you think you are deficient in a particular nutrient, always check with your doctor before loading up on vitamins, Caprara advises. But at the end of the day, a well-balanced diet should have you and your nutrient needs sufficiently covered.