The single most important thing to take when trying to get pregnant is a prenatal vitamin with at least 400 micrograms of folic acid, ideally started one to three months before you conceive. But folic acid is just the starting point. A handful of other nutrients play meaningful roles in egg quality, ovulation, sperm health, and early embryo development, and the timing of when you start matters almost as much as what you take.
Folic Acid: The Non-Negotiable
Folic acid prevents neural tube defects, which are serious birth defects of the brain and spine that develop in the first few weeks of pregnancy, often before you even know you’re pregnant. The CDC recommends 400 mcg daily for all women who could become pregnant, and the American College of Obstetricians and Gynecologists advises starting at least one month before conception and continuing through the first 12 weeks. Most prenatal vitamins contain this amount. If you’ve previously had a pregnancy affected by a neural tube defect, the recommendation jumps to 4,000 mcg daily, starting at least three months before conception.
A Good Prenatal Vitamin Covers the Basics
Beyond folic acid, a quality prenatal vitamin should include iodine and iron. During pregnancy, you need 220 mcg of iodine daily to support your baby’s brain development, and the NIH recommends starting a 150 to 200 mcg iodine supplement before conception. Not all prenatals include iodine, so check the label. Iron needs rise to 27 mg daily during pregnancy, and vegetarian or vegan women are advised to supplement with at least 30 mg daily.
Rather than buying these nutrients separately, look for a prenatal vitamin that bundles them. Starting your prenatal two to three months before trying to conceive gives your body time to build up adequate stores, especially for nutrients like folate and iodine that matter most in the earliest weeks.
Vitamin D and Conception Rates
Vitamin D deficiency, defined as blood levels below 20 ng/mL, is linked to lower pregnancy rates. A study in Fertility and Sterility found a statistically significant negative correlation between vitamin D deficiency and clinical pregnancy rates. Many women are deficient without knowing it, particularly those who live in northern climates, have darker skin, or spend most of their time indoors. A simple blood test can check your levels. Most prenatal vitamins contain some vitamin D, but if your levels are low, you may need a separate supplement to bring them into a healthy range.
CoQ10 for Egg Quality
Your eggs contain more energy-producing structures (mitochondria) than almost any other cell in your body, because egg development and early embryo growth demand enormous amounts of energy. Coenzyme Q10, or CoQ10, fuels those mitochondria and protects cells from oxidative damage. Your body’s natural CoQ10 production declines with age, which is one reason egg quality tends to drop after 35.
Most fertility-focused studies use 200 to 600 mg per day, divided into two or three doses. For women over 35, many reproductive endocrinologists recommend 300 to 600 mg daily for at least 8 to 12 weeks before trying to conceive. Ubiquinol, the active form of CoQ10, is often preferred for women over 35 because it’s absorbed more efficiently as you age, meaning lower doses can achieve similar effects.
Omega-3 Fatty Acids
The omega-3 fats DHA and EPA support fertility by helping regulate hormones involved in ovulation and increasing blood flow to the uterus. A well-supplied uterine lining is important for implantation. Fatty fish like salmon, sardines, and mackerel are the best food sources, but a fish oil supplement providing at least 200 to 300 mg of DHA is a common recommendation during the preconception period and pregnancy. Many prenatal vitamins now include DHA, though often at modest doses.
Inositol for Ovulation Support
If you have PCOS or irregular ovulation, inositol is worth knowing about. Myo-inositol is a naturally occurring compound that helps cells respond to insulin, and insulin resistance is a central driver of PCOS-related ovulation problems. Research in Frontiers in Endocrinology supports combining myo-inositol with D-chiro-inositol in a 40:1 ratio, which mirrors the natural ratio found in blood plasma. Supplements formulated at this ratio have shown promising results in restoring ovulation and reducing PCOS symptoms. Typical doses use around 4,000 mg of myo-inositol paired with 100 mg of D-chiro-inositol daily.
If you ovulate regularly and don’t have PCOS, inositol is unlikely to offer significant benefits.
What Your Partner Can Take
Fertility is a two-person equation. Sperm take about 70 to 90 days to develop, so any supplement a male partner starts should be taken for at least three months before expecting results.
L-carnitine has some of the strongest evidence among male fertility supplements. Doses between 1 and 3 grams per day for three to six months have been shown to improve sperm concentration, motility (how well sperm swim), and overall quality in men with fertility issues. A study combining 2 grams of L-carnitine with 1 gram of acetyl-L-carnitine daily for six months showed improvements in men with low sperm counts and poor motility.
Zinc, selenium, and CoQ10 also appear in many male fertility formulations. A combined supplement containing L-carnitine alongside these micronutrients improved sperm concentration, motility, and shape in clinical trials, though specific dosages for zinc and selenium are less firmly established than for L-carnitine. A basic men’s fertility multivitamin that includes these nutrients is a reasonable starting point.
Herbs to Avoid While Trying to Conceive
Some popular herbal supplements can interfere with conception or harm an early pregnancy. St. John’s Wort, dong quai, blue cohosh, and black cohosh can all induce uterine contractions. Pennyroyal oil is outright toxic and has been used historically as an abortifacient. Wild yam is a uterine stimulant. Korean ginseng and American ginseng lack established safety data for pregnancy.
If you’re taking any herbal supplements, review them before you start trying. The risk isn’t always obvious from the label, especially with herbal blends marketed for “women’s health” that may contain blue cohosh or dong quai.
When to Start and How Long It Takes
The ideal preconception window is three months before you start trying. This gives folic acid time to build up protective levels, allows CoQ10 to influence the eggs maturing in your current cycle (egg maturation takes roughly 90 days), and gives your partner’s sperm a full development cycle under better nutritional conditions. At minimum, start a prenatal vitamin with folic acid and iodine one month before conception.
Supplements support your body’s fertility, but they don’t override other factors like timing intercourse around ovulation, managing underlying conditions, or age-related changes. Think of them as building the best possible foundation for conception rather than a fix for every barrier. If you’ve been trying for 12 months without success (or 6 months if you’re over 35), that timeline matters more than which supplements you’re taking.