A cross-sectional study of 97 women with infertility in Spain found that dietary intake of specific nutrients was associated with body composition and reproductive hormone levels.
Study Overview
The study included women aged 18–40 meeting infertility criteria (no conception after 12 months of unprotected intercourse, or 6 months if over 35), attending a fertility clinic between 2022 and 2024. Women with polycystic ovary syndrome, endometriosis, or endocrine diseases requiring treatment were excluded.
Dietary intake was assessed using a validated food frequency questionnaire. Anthropometric measurements (BMI, waist-to-hip ratio, body fat percentage, muscle mass percentage) were obtained via bioelectrical impedance analysis. Hormones (AMH, FSH, LH, TSH, estradiol, calcidiol, prolactin) were measured from fasting blood samples in the early follicular phase.
Statistical analyses used correlation tests and multiple linear regression, adjusting for caloric intake, physical activity, BMI, and smoking status. Significance was set at p<0.05 with Bonferroni correction for multiple comparisons.
Key Findings
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Mean age of participants was approximately 33 years. Average BMI was in the overweight range; body fat percentage exceeded recommended levels; muscle mass percentage was slightly below optimal.
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Riboflavin (vitamin B2) intake showed a positive correlation with muscle mass percentage, though the association was nominal after adjustment. Calcium intake was also positively associated with muscle mass.
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Vitamin E intake was inversely associated with hip circumference and with prolactin levels (higher prolactin can disrupt ovulation). Associations persisted after adjustment.
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Associations between other nutrients and AMH or TSH were not significant after adjustment.
Limitations
The cross-sectional design cannot establish causality. Long-term prospective studies are needed to validate findings.
The study was published in Scientific Reports.