A peer-reviewed study and a new supplement brand are exposing a decades-long gap in the science behind prenatal nutrition
The prenatal vitamin sitting on your nightstand was almost certainly formulated according to dietary guidelines based on research that largely excluded pregnant women. A peer-reviewed analysis and a growing consumer movement are now forcing a serious reckoning with that gap.
The supplement brand Needed has entered the market, arguing that standard prenatal formulas were never properly validated for the people who take them. The brand highlights the striking fact that only about 5% of the studies informing nutrition guidelines include pregnant women, a figure that has alarmed researchers and expectant parents alike.
That number reflects a systemic problem in how nutrition science has historically treated pregnancy as an afterthought rather than a distinct physiological state requiring dedicated study.
What The Peer-Reviewed Evidence Actually Shows
The academic case behind this concern is detailed. Researchers screened 704 studies drawn from Dietary Reference Intake reports covering 23 micronutrients and found that women were excluded from nearly a quarter of those studies, and pregnant or lactating people appeared in only 17% of the reviewed research.
Across all studies in which women participated, they accounted for roughly 29% of the combined sample size. The analysis was published in the American Journal of Clinical Nutrition in October 2021.
The problem is not just about raw numbers. The most rigorous study designs — controlled feeding trials and stable isotope studies, the methods that carry the most weight when setting guidelines — showed the strongest tendency toward all-male participant pools. That means the highest quality evidence underpinning nutrient recommendations is also the evidence least likely to reflect what happens inside a pregnant body.
The researchers drew a pointed parallel to the COVID-19 pandemic, noting that less than 2% of all registered COVID-19 trials included pregnant people, even for treatments using medications or micronutrients with well-established safety profiles. The authors argued that pregnant people should be protected through research rather than from research, and called urgently upon funders and researchers to address fundamental gaps in knowledge with high-quality studies.
The Framework Behind Every Prenatal Supplement
To understand why this matters for the supplement in your medicine cabinet, it helps to know how nutrient guidelines get made.
The Dietary Reference Intakes, or DRIs, are the foundational framework used across the United States and Canada to set recommended nutrient levels.
Governments rely on them to shape food policy, and the private sector uses them to formulate dietary supplements, including prenatal vitamins.
According to a PubMed-indexed history of the DRI framework, the system was conceptualized in 1994, with the first reports issued between 1997 and 2004 by expert panels under the Food and Nutrition Board of the Institute of Medicine.
The DRIs have shaped national nutrition policies that touch on dietary guidance, food labeling, food assistance programs, and military nutrition standards.
Yet the same historical account carries a sobering warning: no updates to specific DRI values are currently planned. Its authors wrote in Advances in Nutrition that “despite the long and challenging road that led to the current DRIs, it must not finish in a dead end,” stressing that monetary resources and political will are crucial to maintaining and continuously updating the guidelines.
Without both, the research gap affecting pregnant women could persist for another generation.
Race And Ethnicity Data Compound The Problem
The 2021 peer-reviewed study added another layer of concern beyond sex representation. Across the 704 studies examined, race and ethnicity data went unreported in more than 90% of cases.
The DRIs are intended for use across the general population of the United States and Canada and are widely adopted globally for public health programming.
If the underlying research drew almost exclusively from populations that were both male and racially unspecified, the guidelines carry compounded blind spots for women of color and people in lower and middle-income countries.
The biological case for studying pregnant people specifically is not abstract. Pregnancy triggers profound physiological changes that alter how the body absorbs, distributes, metabolizes, and excretes nutrients.
A supplement dose calibrated for a non-pregnant adult, let alone a male adult, may behave very differently in a pregnant body.
Researchers have also pointed to emerging evidence that maternal nutritional status during pregnancy has lifelong consequences for fetal health and the child’s future well-being, raising the stakes for getting the science right.
For expectant parents navigating supplement choices today, understanding what goes into the best over-the-counter prenatal vitamins is more important than ever.
Questions worth asking include: Who was studied when this formula was developed? Does the brand cite research conducted in pregnant populations? Is the dosing based on DRI values derived from pregnant participants, or extrapolated from other groups?
A Consumer Brand Steps Into A Scientific Void
The emergence of Needed reflects a broader shift in how pregnant women and their caregivers are approaching supplement decisions. Awareness is growing that a “prenatal” label does not automatically mean the formula was validated in pregnant populations.
The brand has built its identity around the argument that standard prenatal vitamins were effectively formulated using data that did not account for the distinct nutritional needs of pregnancy, and it is not alone in making that case.
Academic researchers, bioethicists, and public health advocates have been raising the same alarm for years.
The story of prenatal vitamins and the research gap behind them is ultimately a story about whose bodies science has historically treated as the default.
Pregnant women were excluded from foundational nutrition research not because the science demanded it, but because of assumptions about risk and logistical convenience that researchers and ethicists are now actively challenging.
The fact that a consumer brand is filling a gap that federal guidelines have not yet addressed says something important about the pace of institutional change and how much work remains before the science of pregnancy nutrition fully catches up with the people living it.
