Nutrient Deficiencies in Infertility – What Does Research Say?

What the 2026 NHANES study investigated

The analysis was published in January 2026 in the journal PLOS ONE (Murphy et al.). It is based on data from the National Health and Nutrition Examination Survey, one of the largest and most methodologically robust health surveys in the USA. The study included women of reproductive age, some of whom reported having tried unsuccessfully to become pregnant for at least twelve months. This group was classified as infertile in the analysis, but based on self-reported information, not a medical diagnosis.

How was nutrient intake measured?

Intake was recorded using two 24-hour dietary recalls, one in-person interview and a later telephone interview. Because no one eats the same every day, the researchers used a statistical method (the NCI method) to calculate an estimated usual intake. This smooths out random fluctuations and reflects long-term supply more realistically. This is exactly what makes the study more reliable than a simple daily average.

What deficiency means here

An important point that is often misunderstood: the study does not measure a deficiency in the body itself. It calculates the proportion of women below the Estimated Average Requirement (EAR). Below this, the probability of inadequate intake is statistically increased. It is therefore about the probability of insufficient dietary intake, not a medical diagnosis. However, those who consistently consume too little risk long-term undernourishment.

What the study shows and what it doesn't

This is a cross-sectional analysis; nutrient intake and fertility status were assessed at the same time. It cannot be concluded from this whether a nutrient deficiency contributed to infertility or whether other factors such as stress, illnesses, or changes in eating habits due to unfulfilled desire to have children influenced both. Also, infertility was self-reported, not clinically diagnosed. This is common and valid for a population study but means that other causes cannot be ruled out.

However, what the analysis clearly shows is that there are measurable, systematic differences in micronutrient supply between the two groups. This is not a coincidence and is highly relevant for advising women who wish to conceive.

Which nutrients are particularly important for fertility

Beyond the NHANES data, the same nutrients repeatedly appear in fertility research. Folate (folic acid) is best documented: A good folate status before conception reduces the risk of neural tube defects, which is why professional societies recommend taking it even before pregnancy. You can read more about this in our article on Folic acid and folate for fertility.

In addition, antioxidants such as selenium, zinc, and vitamin E are associated with protecting egg cells from oxidative stress, omega-3 fatty acids with a favorable hormonal environment, and vitamin D with cycle regulation. For PCOS or reduced egg reserve, myo-inositol is also being investigated. You can find an overview of nutrients for fertility in our Guide to nutrients for fertility, specifically on egg maturation in our article Improve egg quality.

Why the pattern counts, not the single capsule

The most honest conclusion from the research: More important than a single supplement is the overall dietary pattern. A Mediterranean diet with vegetables, legumes, nuts, olive oil, and fatty fish is associated with better reproductive health in both women and men. Dietary supplements can fill gaps but do not replace a good basic diet.

Key Facts at a Glance

• Real Gaps, No Causation: The NHANES analysis shows lower nutrient intake in women with infertility but does not prove a causal link.
• Vitamin E Stands Out: Over 87 percent of affected women were below the reference value for vitamin E.
• Intake, Not Blood Level: Typical dietary intake was measured, supplements separately.
• No Magic Bullet: Nutritional supplements do not cure infertility but can support a favorable environment.
• Pattern Trumps Single Pill: A Mediterranean, nutrient-rich diet is the most important lever for both partners.

When You Should Seek Medical Advice

If you are under 35 and have been trying to conceive unsuccessfully for about a year, or over 35 for around six months, medical clarification is advisable. An early consultation is also worthwhile for irregular or absent cycles, known PCOS, endometriosis, or thyroid problems. Dietary supplements do not replace this clarification.

Conclusion

The NHANES analysis does not prove that a lack of nutrients causes infertility. However, it shows that many women of reproductive age are not optimally nourished, and this is particularly common in those with unfulfilled desire to have children. Targeted, well-coordinated provision is therefore not a luxury, but a sensible foundation. If you want to know where you actually stand, let's look at it together.