Causal Associations of Circulating Micronutrients With the Risk of Infertility: A Mendelian Randomization Study

Area of Science:

• Nutritional Epidemiology
• Reproductive Health
• Genetic Epidemiology

Background:

• Infertility affects millions globally, with growing evidence linking micronutrients to reproductive health.
• Understanding these links is crucial for developing effective fertility interventions.

Purpose of the Study:

• To investigate the causal relationships between 15 key micronutrients and infertility in both males and females.
• To provide insights into nutritional epidemiology for improving fertility outcomes.

Main Methods:

• A Mendelian randomization (MR) study utilizing genome-wide association study (GWAS) data from European-ancestry cohorts.
• Primary analysis employed inverse-variance weighted MR, with MR-Egger and weighted median approaches for robustness.
• Examined genetic associations for 15 micronutrient biomarkers and infertility phenotypes.

Main Results:

• Genetically predicted higher levels of selenium, iron, and beta-carotene showed inverse associations with female infertility risk, suggesting protective effects.
• Elevated phosphorus levels were strongly associated with an increased risk of male infertility.
• No significant causal associations were found for the other 11 evaluated micronutrients.

Conclusions:

• Selenium, iron, and beta-carotene may play protective roles in female infertility.
• Phosphorus is identified as a potential risk factor for male infertility.
• Findings support the development of sex-specific nutritional strategies to enhance fertility.