The single most important supplement to start before trying to get pregnant is folic acid, at 400 micrograms per day. Beyond that, a good prenatal vitamin plus a few targeted nutrients can meaningfully support both egg quality and a healthy early pregnancy. Ideally, you should begin this routine at least one to three months before you start trying.
Folic Acid: The Non-Negotiable Starting Point
Folic acid prevents neural tube defects, which are serious birth defects of the brain and spine that develop in the earliest weeks of pregnancy, often before you even know you’re pregnant. The CDC recommends 400 mcg daily for all women capable of becoming pregnant. If you’ve had a previous pregnancy affected by a neural tube defect, the recommendation jumps to 4,000 mcg daily, starting at least one month before conception and continuing through the first trimester.
Most prenatal vitamins contain 400 to 800 mcg of folic acid, which covers the baseline. But there’s a nuance worth knowing: folic acid is a synthetic form of folate that your body has to convert before it can use it. Some people carry a common genetic variation that makes this conversion less efficient. A form called 5-methyltetrahydrofolate (often listed as “methylfolate” on labels) skips that conversion step entirely and is immediately available to your body. Research from Georgetown Medical Review notes that methylfolate has increased bioavailability and works regardless of genetic differences in folate metabolism. The tradeoff is that methylfolate costs more and has a smaller evidence base specifically for neural tube defect prevention. If you’re unsure whether you carry this genetic variation, choosing a prenatal with methylfolate is a reasonable hedge.
Vitamin D and Fertility Outcomes
Vitamin D plays a role in reproductive health that goes beyond bone strength. A study of women undergoing IVF found that those with sufficient vitamin D levels before conception had significantly higher pregnancy rates. The threshold that mattered was a blood level of at least 50 nmol/L (about 20 ng/mL). Women above that level were roughly twice as likely to achieve a successful pregnancy compared to those below it.
Many women of childbearing age are vitamin D deficient, especially those who live in northern climates, have darker skin, or spend limited time outdoors. Most prenatal vitamins contain 400 to 600 IU, but many fertility specialists suggest higher amounts. A simple blood test can tell you where you stand, and your levels can guide how much you actually need.
CoQ10 for Egg Quality
If you’re over 35 or concerned about egg quality, Coenzyme Q10 (CoQ10) is worth considering. Human eggs contain more mitochondria, the tiny energy-producing structures inside cells, than any other cell in the body. As you age, mitochondrial function in eggs declines, which may contribute to lower egg quality and higher rates of chromosomal abnormalities. CoQ10 is a key component of the energy production process inside mitochondria, and supplementing with it may help eggs maintain the energy reserves they need to divide normally.
Typical doses range from 100 to 300 mg per day, though some fertility clinics recommend up to 600 mg daily in divided doses. Studies have shown it’s safe at doses up to at least 1,200 mg per day. It’s not a magic fix, but for women approaching their late 30s or 40s, the biological rationale is strong enough that many reproductive endocrinologists recommend it as part of a preconception plan.
Iron: Building Reserves Before Pregnancy
Your iron needs increase substantially during pregnancy, jumping from 18 mg per day to 27 mg per day, because your body produces significantly more blood to support the growing fetus. Starting pregnancy with low iron stores makes it harder to keep up. Most prenatal vitamins include iron, which is one reason to start taking them before you conceive rather than waiting for a positive test. If you have heavy periods, follow a vegetarian diet, or have a history of anemia, getting your ferritin levels checked before conception can help you and your provider decide whether you need additional supplementation beyond what’s in a standard prenatal.
Omega-3 Fatty Acids
The omega-3 fats EPA and DHA support fetal brain and eye development, and there’s growing recognition that starting them before pregnancy is beneficial. Most prenatal vitamins include only about 200 mg of DHA, which researchers at the MGH Center for Women’s Mental Health consider likely insufficient. Studies showing improved neurocognitive development in babies used doses in the range of 2 to 3 grams of combined EPA and DHA per day. A standalone fish oil or algae-based omega-3 supplement can bridge the gap. Look for products with roughly equal amounts of EPA and DHA, or slightly more EPA.
Vitamin A: One to Be Careful With
Vitamin A is essential for fetal development, but too much of the preformed type (retinol) can cause birth defects. The European Food Safety Authority sets the upper limit at 3,000 mcg per day for women of childbearing age, while UK guidelines recommend staying under 1,500 mcg per day. The practical takeaway: avoid liver and liver products like pâté while trying to conceive, and skip standalone vitamin A supplements or fish liver oil capsules. Your prenatal vitamin will contain a safe amount, often partly as beta-carotene, which your body converts to vitamin A only as needed and doesn’t carry the same risk.
Supplements That Support Your Partner
Fertility is a two-person equation, and several nutrients have solid evidence behind them for improving sperm quality. If your partner’s sperm count, motility, or overall semen quality is a concern, these are the most studied options:
- Zinc: In a controlled trial, men with low sperm motility who took zinc twice daily for three months saw significant improvements in sperm quality, count, motility, and fertilizing capacity.
- Selenium: A double-blind study found that 100 mcg per day for three months significantly increased sperm motility in infertile men, though it didn’t affect count.
- Vitamin E: Men with low fertilization rates during IVF who took 200 IU daily saw significant improvements in fertilization rates after just one month, along with reduced oxidative damage to sperm.
- Vitamin B12: In one study, approximately 60% of infertile men who took 1,500 mcg of methylcobalamin daily experienced improved sperm counts over 2 to 13 months.
- L-carnitine: Preliminary research found that 3 to 4 grams per day for four months helped normalize sperm motility in men with low sperm quality.
- CoQ10: Even doses as low as 10 mg per day over two weeks increased both sperm count and motility in some studies.
A men’s fertility multivitamin typically bundles several of these together. The effects generally take two to three months to show up, since sperm take about 74 days to fully mature.
When to Start and What to Prioritize
The American College of Obstetricians and Gynecologists recommends starting a prenatal vitamin in the months before you try to conceive. At minimum, begin one month before, but three months gives nutrients like folic acid and CoQ10 more time to build up in your system and gives your partner’s sperm a full maturation cycle on any new supplements.
If you’re overwhelmed by the options, here’s the simplest version: a quality prenatal vitamin with at least 400 mcg of folic acid (or methylfolate), iron, and vitamin D covers the essentials. Add a standalone omega-3 supplement for adequate DHA and EPA. If you’re over 35, add CoQ10. Everything else is worth discussing with your provider based on your specific lab work and health history.