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Question: I’ve heard that prenatal vitamins can help improve hair quality, balance hormones, prevent acne and make fingernails stronger. Should I consider taking them even though I’m not pregnant?
Answer: The notion that prenatal vitamins affect hormone levels or the quality of skin, hair and nails is a myth that likely has its origins in the observation that pregnant women (who are generally taking prenatal vitamins) have fast-growing, healthy-looking hair and nails, and glowing skin. However, the changes in skin, hair and nails experienced by pregnant women are due to hormonal changes associated with pregnancy, and have nothing to do with prenatal vitamins.
Prenatal vitamins are multivitamin and mineral supplements specifically formulated for pregnant women. Compared to a regular multivitamin, prenatals have more iron and folic acid. The extra iron (27 mg/day for pregnant women, versus 18 mg/day for non-pregnant women) is important to the production of additional red blood cells, which carry oxygen to the tissues. Folic acid, one of the B-vitamins, helps to promote normal development of the neural tube. Deficiencies in folic acid during pregnancy increase the risk of spina bifida and other neural tube defects in the developing fetus. Pregnant women need 600 mg of folic acid a day, compared to 400 mg/day for non-pregnant women.
There is no scientific evidence — nor is there a plausible hypothesis — to suggest that prenatal vitamins affect hormone levels or confer any particular benefit upon non-pregnant women. Further, prenatals contain large quantities of iron, which can be toxic in excess. Still, it’s unlikely that the iron in prenatals would be sufficient to cause iron toxicity in an otherwise healthy female. Men and children, who have much lower iron requirements and tolerances, should not take prenatal vitamins.
There is one group of non-pregnant individuals who potentially stands to benefit from prenatal vitamins: women who are actively trying to conceive. However, the extra iron isn’t actually necessary until the second trimester of pregnancy, and many women find that it upsets the gut, leading to nausea and constipation. As such, women who are attempting to become pregnant may prefer a regular multivitamin, plus an additional folic acid supplement. Of course, it’s important to discuss all supplement decisions with a healthcare practitioner.
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