A novel study issued in ‘Reproductive Biology & Endocrinology’ revealed that antioxidant vitamins such as vitamin D, vitamin C, and vitamin E can be effective in countering oxidative stress and provide pain relief in women with endometriosis.  Researchers sought to illuminate the impact of antioxidant vitamin supplementation on pain linked with endometriosis.

The study employed an extensive search of the leading databases (PubMed, Web of Science, Cochrane Library, Scopus, and China National Knowledge Infrastructure [CNKI]), up to March 16, 2023, to look for relevant literature. Their focus was on studies (English and Chinese), employing search terms like endometriosis" OR "endometrioma" OR "endometrium" AND "antioxidant" OR "Vitamin C" OR "Vitamin E" OR "Vitamin D" OR "25-OHD" OR "25(OH)D" OR "25-hydroxyvitamin D".

Eligible studies included randomized controlled trials (RCTs) that used the visual analogue scale (VAS) to evaluate pain scores. The Cochrane Risk of Bias Tool was used for quality assessment, following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The meta-analysis incorporated data from 13 RCTs involving 589 patients. Out of these RCTs, 11 studies investigated the impact of antioxidant vitamin supplementation on endometriosis-related pain.

The results unequivocally showed that antioxidant vitamins can effectively alleviate such pain.

Particularly, subgroup analysis revealed that vitamin E supplementation, either alone or in combination with vitamin C, considerably improved clinical pelvic pain in those with chronic pelvic pain. Conversely, vitamin D supplementation showed a reduction in pelvic pain among endometriosis patients, although it was not statistically significant. Additionally, the study reported changes in oxidative stress markers following the use of vitamin therapy, with a decrease in plasma malondialdehyde (MDA) concentration, which was inversely linked to the duration and dosage of vitamins E and C.

The inflammatory markers in peritoneal fluid (RANTES, monocyte chemoattractant protein-1 and interleukin-6) also significantly decreased, demonstrating a decrease in inflammation. The studies encompassed in this analysis endorse the prospective contribution of antioxidant vitamins to address endometriosis.

Incorporating antioxidant vitamins into the treatment regimen significantly mitigated dysmenorrhea, ameliorated dyspareunia and pelvic discomfort, and enhanced the overall quality of life among affected individuals. Consequently, the adoption of antioxidant vitamin therapy emerges as a viable option, either as a standalone treatment or in conjunction with other modalities, for alleviating pain associated with endometriosis.