Getting all the nutrients you need for fertility from food alone is tough. Hedge your bets by taking a prenatal vitamin or regular multivitamin. Although prenatal vitamins will give you the key nutrients you need, they may be more expensive and they can be harder on your stomach because they contain higher levels of nutrients than a regular multivitamin. If you decide to take an over-the-counter multivitamin instead of a prenatal vitamin, be sure to follow these important guidelines:

• Make sure it doesn’t contain more than the recommended daily allowance of 770 mcg (2,565 IU) of vitamin A, unless it’s all in a form called beta-carotene. Getting too much of a certain kind of vitamin A can cause birth defects. (The kind that occurs naturally in food is safe, so you don’t have to worry about overdoing it by eating foods rich in vitamin A.)
• Look for a multivitamin with at least 400 micrograms of folic acid. This B vitamin protects babies from neural tube birth defects, such as spina bifida. It’s especially important to get enough folic acid before you get pregnant, because your baby’s neural tube forms just three to four weeks after conception when many women don’t even realize they’re pregnant.
• Choose a multivitamin that also delivers a healthy dose of vitamin B12. Preliminary evidence hints that B12 deficiency may also play a role in some neural tube defects. Because vitamin B12 is found primarily in animal-based foods, women who rarely eat meat or follow a strict vegetarian or vegan diet should either look for a multivitamin that delivers the entire B12 recommended daily allowance (2.4 micrograms) or consider taking a B12 supplement.

If you’re unsure what to take, ask your healthcare provider to recommend a supplement for you.