The single most important supplement when trying to get pregnant is folic acid, at 400 to 800 micrograms daily, started at least three months before you conceive. But folic acid is just the starting point. Several other nutrients play direct roles in egg quality, ovulation, hormone balance, and preparing your uterus for implantation. Here’s what the evidence supports and how much you actually need.
Folic Acid: The Non-Negotiable
Folic acid prevents neural tube defects, which are serious malformations of the brain and spine that develop in the earliest weeks of pregnancy, often before you know you’re pregnant. The US Preventive Services Task Force gives folic acid its highest recommendation grade: all women planning or capable of pregnancy should take 400 to 800 mcg daily. In the landmark clinical trial that established this, women taking folic acid had zero neural tube defects compared to a 0.25% rate in the control group.
Start at least three months before you begin trying. This gives your body time to build up adequate folate levels in the blood and tissues. A standard prenatal vitamin covers this, but check the label to confirm the dose falls in the 400 to 800 mcg range.
You may have seen advice online that people with MTHFR gene variants should skip folic acid and take methylfolate instead. The CDC directly addresses this: it’s not true. People with common MTHFR variants can process folic acid normally, and folic acid is the only form of folate proven to prevent neural tube defects. Your daily intake matters far more than your MTHFR genotype for determining blood folate levels.
Vitamin D and Pregnancy Rates
Vitamin D plays a measurable role in fertility outcomes. A large meta-analysis of women undergoing fertility treatment found a clear link between vitamin D levels and both clinical pregnancy rates and live birth rates. The relationship was strongest below about 24 ng/mL. Below that threshold, pregnancy rates dropped noticeably. Above it, improvements continued but more gradually.
Many women are deficient without knowing it, especially those who live in northern climates, have darker skin, or spend most of their time indoors. A simple blood test can check your level. If you’re low, supplementation with vitamin D3 can bring you into range relatively quickly, and most prenatal vitamins contain some vitamin D, though not always enough to correct a deficiency on their own.
CoQ10 for Egg Quality
CoQ10 is an antioxidant your cells use to produce energy. It’s concentrated in mitochondria, the tiny power plants inside every cell, and eggs are among the most mitochondria-dense cells in your body. As you age, mitochondrial function in eggs declines. This is one reason fertility drops with age: eggs literally have less energy to fuel the complex process of dividing correctly after fertilization.
Animal research published in Aging Cell showed that CoQ10 supplementation restored mitochondrial function in aged eggs to levels comparable to young eggs. Specifically, it increased ATP output (the cell’s energy currency), improved oxygen consumption, normalized the mitochondrial membrane, and reduced the kind of oxidative stress that damages DNA. Perhaps most striking, CoQ10 treatment restored normal chromosome alignment during cell division, reducing the chromosomal errors that lead to miscarriage and genetic abnormalities.
These studies were done in mice, so direct dosing translations aren’t perfect. However, many reproductive endocrinologists recommend CoQ10 (often in the ubiquinol form, which is more easily absorbed) for women over 35 or those with diminished ovarian reserve. It takes time to affect egg quality since eggs mature over roughly three months, so starting early matters.
Iron and Ovulation
Iron deficiency doesn’t just cause fatigue. It can directly interfere with ovulation. A study following thousands of women over eight years found that women who took iron supplements had a 40% lower risk of ovulatory infertility compared to women who didn’t. The benefit came specifically from non-heme iron, the type found in supplements, fortified cereals, beans, and leafy greens. Heme iron from meat didn’t show the same protective effect.
This doesn’t mean you should take high-dose iron without reason. Too much iron causes its own problems, including nausea and constipation. But if your periods are heavy or you eat a mostly plant-based diet, getting your iron levels checked and supplementing if needed could make a real difference for your cycle regularity.
Omega-3 Fatty Acids
Omega-3s, particularly EPA and DHA from fish oil, support fertility through several pathways. They help regulate the production of prostaglandins, hormone-like compounds that influence uterine function and the hormonal signaling involved in ovulation. They also reduce chronic low-grade inflammation, which can interfere with how reproductive organs function and may contribute to conditions like endometriosis that impair fertility.
Beyond conception, omega-3s are critical for fetal brain and eye development, so building up your stores before pregnancy gives your baby a head start. If you don’t eat fatty fish like salmon or sardines at least twice a week, a fish oil supplement providing both EPA and DHA is a practical option. Look for one tested for mercury and other contaminants.
Choline: The Overlooked Nutrient
Choline rarely gets the attention of folic acid, but it plays a similarly early role. It supports fetal brain development from the very first weeks, potentially before you even get a positive test. The recommended intake jumps to 450 mg per day during early pregnancy, up from 425 mg for non-pregnant women. Most prenatal vitamins contain little or no choline, and most women fall well short of even the baseline recommendation through diet alone.
Good food sources include eggs (one large egg has about 150 mg), liver, salmon, and soybeans. If your diet is light on these, a standalone choline supplement or a prenatal that specifically includes it can fill the gap. Starting before conception ensures adequate levels are in place during those critical first weeks.
What to Avoid: Vitamin A Caution
Not all vitamins are “more is better” territory when trying to conceive. Preformed vitamin A (retinol), the type found in liver, some supplements, and certain skin care products, can cause birth defects at high doses. These include malformations of the eyes, skull, lungs, and heart. The safe upper limit during pregnancy is 3,000 mcg RAE (10,000 IU) per day from preformed sources.
Beta-carotene, the form of vitamin A in carrots, sweet potatoes, and other orange and green vegetables, does not carry this risk because your body only converts what it needs. Check your prenatal vitamin to confirm its vitamin A comes from beta-carotene rather than retinol, or that the retinol content stays well below the upper limit. If you use retinoid skin creams, switch to pregnancy-safe alternatives before you start trying.
When to Start and What to Prioritize
Three months before you start trying is the minimum lead time, and it applies to more than just folic acid. Egg development takes about 90 days from early recruitment to ovulation, so any supplement aimed at improving egg quality (like CoQ10) needs that runway. Vitamin D levels also take weeks to shift meaningfully with supplementation.
A good prenatal vitamin covers folic acid, vitamin D, and iron as a baseline. From there, consider adding CoQ10 if you’re over 35 or have concerns about egg quality, omega-3s if your diet is low in fatty fish, and choline if your prenatal doesn’t include it. Get your vitamin D and iron levels tested so you know whether standard prenatal doses are enough or whether you need more targeted supplementation.