Vitamins and fertility
Pro Research Analysisby 
Searched over 200M research papers
Vitamin D and Female Fertility: PCOS, Endometriosis, and IVF Outcomes
Vitamin D plays a significant role in female reproductive health. Its receptors and metabolizing enzymes are present in reproductive tissues such as the ovary, uterus, and placenta, suggesting a direct influence on fertility processes 1246+2 MORE. Research shows that vitamin D may help regulate sex hormone production and is involved in conditions like polycystic ovary syndrome (PCOS) and endometriosis. Low vitamin D levels are linked to metabolic and hormonal disturbances in PCOS, and supplementation may improve menstrual regularity and metabolic health in these women 1267+1 MORE. Vitamin D deficiency is also associated with endometriosis, possibly due to its immunomodulatory and anti-inflammatory effects 2678. Some studies suggest that higher vitamin D levels may be associated with better outcomes in in vitro fertilization (IVF), but the evidence is not strong enough to confirm a direct cause-effect relationship 168.
Vitamin D and Male Fertility: Sperm Quality and Hormone Production
Vitamin D receptors are found in male reproductive organs, including the testis and sperm cells, indicating a potential role in male fertility 1458+2 MORE. Animal studies show that vitamin D deficiency can lead to reduced sperm count, poor motility, and abnormal reproductive organ structure . In humans, most studies agree that vitamin D is positively associated with sperm motility, which is a key factor in male fertility 5910. However, the effect of vitamin D on testosterone and other hormone levels is less clear, with some studies showing a possible link and others finding no significant impact from supplementation 5910. Overall, vitamin D appears to have a more consistent effect on sperm quality than on hormone production.
Nutrient Supplements and Fertility: Broader Evidence
Beyond vitamin D, other nutrient supplements such as antioxidants, L-carnitine, coenzyme Q10, melatonin, myo-inositol, and N-acetylcysteine have been studied for their potential to improve fertility outcomes, especially in women with PCOS or those undergoing medically assisted reproduction (MAR) . Some evidence suggests these supplements may increase live birth and clinical pregnancy rates, but the certainty of this evidence is very low. Importantly, vitamin D supplementation did not show a significant effect on biochemical pregnancy rates or miscarriage rates in women trying to conceive naturally or with MAR . There is also no indication that these supplements cause significant harm .
Mechanisms and Clinical Implications
Vitamin D is involved in several reproductive processes, including steroid hormone production, ovarian function, follicular development, endometrial receptivity, spermatogenesis, and sperm function 1245+5 MORE. Its deficiency is linked to insulin resistance, hormonal imbalances, and inflammation, all of which can negatively affect fertility . Despite promising associations, there is a lack of high-quality randomized controlled trials to confirm the benefits of vitamin D supplementation for fertility in both men and women 2356+2 MORE.
Conclusion
Vitamin D is closely linked to several aspects of male and female fertility, particularly in relation to sperm motility, PCOS, and endometriosis. While maintaining adequate vitamin D levels is important for reproductive health, current evidence does not strongly support routine vitamin D supplementation solely to improve fertility outcomes. More rigorous clinical studies are needed to clarify its therapeutic role in fertility management.
Sources and full results
Most relevant research papers on this topic