Why many prenatal vitamins are missing the mark

When you start looking for a prenatal vitamin, the options can feel overwhelming. Nearly every bottle promises to support a healthy pregnancy. But when you look closely at the actual ingredients and dosages, many prenatal supplements fall short of what research now shows is needed to support both mother and baby.

Over the past decade, scientists have learned far more about how specific nutrients influence fertility, egg quality, fetal brain development, pregnancy outcomes, and postpartum recovery. Unfortunately, many prenatal formulas have not evolved alongside this research. Key nutrients are often missing entirely, included in forms the body cannot easily use, or provided in amounts far below what clinical studies suggest may be beneficial.

At WeNatal, our approach has always been simple: follow the science, prioritize bioavailable nutrients, and support the full reproductive journey from preconception through postpartum. That philosophy guided the formulation of WeNatal for Her, which includes research-backed levels of nutrients that many prenatal vitamins still overlook.

Below are four of the most important nutrients for fertility and pregnancy that are frequently underdosed or missing in conventional prenatal supplements.

The 4 nutrients that truly matter for fertility, pregnancy, and baby’s development

1. Choline: A critical nutrient for baby’s brain development

Choline is one of the most important yet most overlooked nutrients during pregnancy. It plays a central role in cell membrane structure, methylation pathways, and neurotransmitter production. During pregnancy, choline becomes especially important for the developing brain and nervous system of the baby. Research suggests adequate maternal choline intake may influence lifelong cognitive outcomes for children.

A landmark randomized controlled trial found that higher maternal choline intake during pregnancy improved markers of infant information processing speed, a measure linked to cognitive development later in life.

Choline also supports proper neural tube development, alongside folate, and helps regulate gene expression through epigenetic mechanisms.

Despite its importance, most women consume far less choline than recommended. Data from the National Health and Nutrition Examination Survey (NHANES) suggests that average intake among women of reproductive age is around 250–300 mg per day, well below the recommended 450 mg during pregnancy and breastfeeding.

Many prenatal vitamins contain little or no choline at all because it requires more capsule space and can be expensive to include at meaningful levels.

WeNatal for Her contains 400 mg of choline, helping bridge the common gap between dietary intake and recommended levels during pregnancy.

2. Iron: Supporting oxygen delivery and preventing maternal depletion

Iron requirements increase dramatically during pregnancy. The body must produce additional red blood cells to support the growing placenta and fetus, increasing iron needs by nearly twofold. Iron deficiency is one of the most common nutrient deficiencies worldwide among women of reproductive age. In pregnancy, inadequate iron status has been associated with:

• Maternal fatigue
• Anemia
• Increased risk of preterm birth
• Low birth weight
• Impaired infant neurodevelopment

Iron status before pregnancy also matters. Women entering pregnancy with low iron stores are more likely to develop iron deficiency anemia as pregnancy progresses. Our clinical nutritionists also find that fatigue during postpartum can be associated with suboptimal iron levels, and when addressed they see a dramatic improvement in mom’s energy levels. 

However, iron supplementation is not one-size-fits-all. Some women benefit from higher therapeutic doses if deficiency is present, while others do best with moderate daily amounts paired with dietary iron intake and clinical monitoring.

WeNatal for Her includes 18 mg of iron, providing foundational support while allowing flexibility for individualized care with healthcare providers if additional iron is needed.

3. Folate: Why the form matters as much as the dose

Folate is one of the most well-known nutrients in prenatal nutrition because of its critical role in preventing neural tube defects. However, the form of folate included in many prenatal supplements remains a topic of increasing discussion in functional and clinical nutrition.

Many conventional prenatals contain folic acid, a synthetic form of vitamin B9. While folic acid has helped reduce neural tube defects globally, research shows that a large percentage of the population carries genetic variations in the MTHFR enzyme, which can reduce the body’s ability to convert folic acid into its active form.

Estimates suggest that 40–60% of people carry at least one MTHFR variant, which can influence how efficiently the body converts folate into its active form. This is one reason the form of folate used in prenatal supplements may matter. 

In a small 2018 clinical study, researchers followed 30 couples who had been experiencing infertility for at least four years, with at least one partner carrying an MTHFR variant. The couples supplemented with 600 micrograms of folate daily for three months. By the end of the study period, nearly half of the couples (13 out of 30) had conceived. While larger studies are still needed, findings like these highlight how supporting the body with the right nutrients can play a meaningful role in fertility.

Active forms of folate such as 5-MTHF (5-methyltetrahydrofolate) are already metabolically active and can be utilized directly by the body.

Adequate folate status supports:

• Neural tube development
• Healthy ovulation and egg maturation
• DNA synthesis and cell division
• Reduced risk of certain congenital abnormalities

WeNatal for Her includes 1,350 mcg of methylated folate (5-MTHF) to help ensure adequate folate status during the critical early weeks of pregnancy, often before a woman even knows she is pregnant.

4. Vitamin D: A hormone that influences fertility and pregnancy outcomes

Vitamin D is often thought of as a nutrient for bone health, but it functions more like a hormone in the body and influences hundreds of genes. Low vitamin D levels have been associated with a range of reproductive health challenges, including infertility, pregnancy complications, and impaired immune regulation.

Emerging research suggests vitamin D status may influence:

• Implantation and endometrial receptivity
• Ovarian follicle development
• Immune tolerance during pregnancy
• Fetal skeletal development

Vitamin D deficiency is extremely common, especially among women living in northern latitudes, those who spend little time in the sun, or individuals with darker skin tones. Some clinical studies have suggested that 4,000 IU per day during pregnancy may be safe and effective in maintaining optimal vitamin D status for both mother and baby.

WeNatal for Her includes 4,000 IU of vitamin D3, aligning with research suggesting higher intake may be needed to maintain healthy blood levels during pregnancy and breastfeeding.

Why prenatal nutrition should start before pregnancy

Another shift in fertility science is the recognition that nutrition before conception matters just as much as nutrition during pregnancy. Egg development begins approximately 90 days before ovulation, meaning the nutrients available during this window can influence egg quality and early embryonic development. The same timeline applies to sperm production.

This is why many fertility specialists recommend beginning prenatal supplementation at least three months before trying to conceive, when possible. Supporting nutrient status early helps ensure the body has the building blocks needed for healthy conception, pregnancy, and postpartum recovery.

Supplements should support a nutrient-dense diet, not replace it

While comprehensive prenatal supplements can help fill nutritional gaps, they are only one piece of the fertility and pregnancy nutrition puzzle. Whole foods remain the foundation for optimal reproductive health. Diets rich in vegetables, fruits, quality proteins, healthy fats, and mineral-rich foods provide fiber, phytonutrients, and compounds that supplements alone cannot replicate.

A thoughtful prenatal formula should work alongside a nutrient-dense diet to support:

• Fertility and optimal hormone levels
• Healthy pregnancy development
• Postpartum recovery
• Long-term health for both mother and baby

Why do many prenatal vitamins not contain choline?

Choline requires large capsule space and is costly to include at meaningful doses, so many prenatal supplements omit it despite research showing its importance for fetal brain development.

Is methylated folate better than folic acid?

Methylated folate (5-MTHF) is the active form of folate that the body can use immediately, which may be beneficial for individuals with MTHFR genetic variants that affect folic acid metabolism.

How much vitamin D should women take during pregnancy?

Some research suggests up to 4,000 IU per day may be safe and effective for maintaining healthy vitamin D levels during pregnancy, though needs vary and should be discussed with a healthcare provider.

When should you start taking a prenatal vitamin?

Many experts recommend starting prenatal vitamins at least three months before trying to conceive to support egg quality, nutrient stores, and early fetal development.

A note from WeNatal on bridging the nutrient gaps in modern prenatal vitamins

Prenatal nutrition has evolved significantly in recent years. As research continues to deepen our understanding of fertility, pregnancy, and early childhood development, it has become clear that many traditional prenatal formulas simply have not kept pace with the science.

At WeNatal, our goal has always been to bridge that gap. By prioritizing bioavailable forms of nutrients, research-backed dosages, and formulas designed for both partners, we aim to support the entire fertility journey, from preconception through pregnancy, postpartum, and beyond.

Whether you're just beginning to think about growing your family or already on that path, the nutrients you provide your body today can influence the health of the next generation. Supporting that process with thoughtful nutrition, lifestyle care, and evidence-based supplementation is one small but powerful step forward.

If you’re looking to support fertility and pregnancy with a prenatal designed around current research, WeNatal for Her was created to help nourish both mother and baby during one of life’s most important transitions.