Researchers used a special genetic study method to look at how 15 different vitamins and minerals might affect fertility in men and women. They found that women with higher levels of selenium, iron, and beta-carotene (a form of vitamin A) appeared to have lower risks of infertility. Interestingly, men with higher phosphorus levels seemed to have higher infertility risk. This study suggests that eating the right nutrients might help people who want to have children, but more research is needed to confirm these findings and understand exactly how these nutrients work.

The Quick Take

  • What they studied: Whether 15 different vitamins and minerals in the blood affect a person’s chances of having trouble getting pregnant
  • Who participated: The study used genetic information from large groups of European ancestry people. Researchers didn’t study people directly but instead analyzed genetic data from existing studies to find patterns
  • Key finding: Women with more selenium, iron, and beta-carotene had lower infertility risk. Men with higher phosphorus had higher infertility risk. The other 11 nutrients studied didn’t show clear connections to infertility
  • What it means for you: If you’re trying to get pregnant, making sure you have enough selenium, iron, and beta-carotene might help—especially for women. However, this is early research, and you should talk to a doctor before making big changes to your diet or taking supplements

The Research Details

This study used a special research method called Mendelian randomization, which is like using genetic clues to figure out if something actually causes a problem. Instead of following people over time, researchers looked at genetic information from very large studies (called GWAS studies) that included hundreds of thousands of people. They examined the genes that affect how much of each nutrient people have in their blood, then checked if those same genes were connected to infertility.

The researchers studied 15 different micronutrients: selenium, iron, beta-carotene, calcium, magnesium, phosphorus, folate, vitamins B6, B12, C, D, zinc, copper, iodine, and manganese. They looked at whether these nutrients affected infertility differently in men versus women. The main analysis method they used is called inverse-variance weighted MR, with two backup methods to double-check their results.

This type of study is valuable because it helps figure out whether a nutrient actually causes infertility problems, rather than just being connected to it. Regular studies can’t always tell the difference—for example, people with infertility might change their diet because they’re trying to get pregnant, which makes it hard to know what caused what. By using genetics, researchers can look at natural differences in nutrient levels that people are born with, which gives a clearer picture of cause and effect.

This study has some strengths: it looked at many nutrients at once, used a strong research method, and studied both men and women separately. However, the study only included people of European ancestry, so the results might not apply to other groups. The study used genetic data rather than measuring actual nutrient intake, which is different from how people actually eat. Also, the sample size for some nutrients wasn’t reported, which makes it harder to judge how reliable some findings are.

What the Results Show

In women, the study found three nutrients that appeared to protect against infertility. Selenium showed the strongest effect—women with higher selenium levels had about 6% lower infertility risk. Iron was also protective, with higher levels linked to about 11% lower infertility risk. Beta-carotene (which your body converts to vitamin A) showed the strongest protection, with higher levels connected to about 13% lower infertility risk.

In men, the results were different. Higher phosphorus levels were actually connected to higher infertility risk—men with more phosphorus had about 4 times higher infertility risk. This was surprising and suggests that too much phosphorus might be harmful for male fertility.

The other 11 nutrients studied (calcium, magnesium, folate, vitamins B6, B12, C, D, zinc, copper, iodine, and manganese) didn’t show clear connections to infertility in either men or women. This doesn’t mean they’re unimportant for fertility, just that this particular study didn’t find strong genetic evidence linking them to infertility risk.

The study found that the effects of nutrients were different for men and women, which is important. This suggests that men and women might need different nutritional approaches for fertility. The fact that phosphorus showed a negative effect in men is particularly interesting because phosphorus is usually considered healthy and important for bones. This finding suggests that balance matters—too much of even a good nutrient might cause problems.

Previous research has suggested that vitamins and minerals are important for fertility, but most studies looked at whether people ate these nutrients or took supplements, not whether the nutrients in their blood actually caused fertility problems. This study adds to that research by using genetics to suggest actual cause-and-effect relationships. The findings about selenium, iron, and beta-carotene support what some earlier research suggested, but the phosphorus finding in men is new and unexpected, so it needs more study to understand what’s happening.

This study has several important limitations. First, it only included people of European ancestry, so we don’t know if these findings apply to other ethnic groups. Second, the study used genetic data, which is different from measuring what people actually eat—genes affect how much nutrient your body absorbs and uses, but that’s not the same as nutrient intake. Third, the study couldn’t explain why these nutrients affect fertility or how they work in the body. Fourth, some of the findings were based on smaller genetic studies, which means they’re less reliable. Finally, the study couldn’t look at whether taking supplements would actually help, since it only studied natural nutrient levels.

The Bottom Line

If you’re trying to get pregnant, especially if you’re a woman, it may be helpful to eat foods rich in selenium (like nuts and fish), iron (like red meat and beans), and beta-carotene (like carrots, sweet potatoes, and leafy greens). However, confidence in these recommendations is moderate because this is early research. Men should be cautious about taking high-dose phosphorus supplements, though getting phosphorus from food is probably fine. Before making any big dietary changes or starting supplements, talk to your doctor, especially if you’ve been trying to get pregnant for a while.

This research is most relevant for couples who are trying to get pregnant and want to know if nutrition might help. It’s also useful for doctors and nutritionists who work with people dealing with infertility. However, if you have normal fertility and just want to eat healthy, this study doesn’t change general nutrition advice. People with kidney disease or other health conditions should definitely talk to their doctor before changing their nutrient intake, since some nutrients can be harmful in certain conditions.

If you start eating more of these nutrients, you probably won’t see immediate results. It typically takes several months for changes in nutrition to affect fertility, since it takes time for your body to build up nutrient levels and for those changes to affect reproductive health. Most fertility specialists recommend trying dietary changes for at least 3-6 months before expecting to see a difference.

Want to Apply This Research?

  • Track daily intake of selenium-rich foods (Brazil nuts, tuna, eggs), iron-rich foods (spinach, beef, lentils), and beta-carotene foods (carrots, sweet potatoes, kale) using a simple food diary or nutrition app. Record 2-3 servings per day of each category and note any changes in energy levels or health markers over 3-month periods.
  • Set a weekly meal plan that includes at least 3 selenium sources, 3 iron sources, and 3 beta-carotene sources. Use the app to create shopping lists and meal reminders. For men, monitor phosphorus intake by logging processed foods and supplements, aiming to avoid excessive amounts while maintaining adequate intake from whole foods.
  • Use the app to track nutrient-rich food consumption weekly and create a 3-month progress report. Monitor overall health markers like energy, sleep quality, and general wellness. If trying to conceive, track fertility-related metrics (cycle regularity for women, general health for men) alongside nutrition data to identify any correlations over time.

This research is preliminary and based on genetic analysis, not direct measurement of nutrient intake or fertility outcomes. These findings should not replace professional medical advice. If you are experiencing infertility, please consult with a fertility specialist or reproductive endocrinologist who can evaluate your individual situation. Do not start, stop, or significantly change supplements or diet without discussing it with your healthcare provider first, especially if you have existing health conditions or take medications. This study was conducted in people of European ancestry and may not apply to other populations. While the findings are interesting, more research is needed to confirm these associations and understand how they work in real-world fertility treatment.