Supplementation with vitamin D or ω-3 fatty acids in adolescent girls and young women with endometriosis (SAGE): a double-blind, randomized, placebo-controlled trial.
What this study found
Overall, vitamin D and omega-3 supplementation did not show clear benefit over placebo for endometriosis-related pain or quality-of-life outcomes. Vitamin D produced within-arm improvement in worst monthly pain from 7.0 to 5.5 and reduced catastrophic thinking from 25.3 to 20.8, but the clinically meaningful pain response was not greater than placebo (OR 1.9, 0.5 to 6.5). Fish oil showed a smaller pain change from 5.9 to 5.2, with no significant advantage over placebo (OR 0.9, 0.2 to 3.7). Across all arms, pain and quality-of-life measures improved similarly, suggesting a strong placebo or…
- Study & population
- Double-blind, randomized, placebo-controlled trial conducted at Boston Children's Hospital in the United States.
- Intervention
- Participants received one of two oral supplements for 6 months: vitamin D3 2000 IU daily (cholecalciferol) or fish oil 1000 mg daily providing 720 mg omega-3 fatty acids, including 488 mg EPA and 178 mg DHA.
- Key limitation
- The trial was conducted at a single center and the active-arm data suggest limited power, with wide confidence intervals around treatment effects.
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Open PDFOriginal abstract
BACKGROUND Adolescents with endometriosis are a particularly underserved population who struggle with chronic pain. Despite widespread use, there are no published trials examining the individual effects of vitamin D and omega-3 (n-3) fatty acid supplementation on endometriosis-associated pain in adolescents. OBJECTIVES We aimed to determine whether supplementation with vitamin D or ω-3 fatty acids remediates pain, changes frequency of pain medication usage, or affects quality of life in young women with endometriosis. METHODS Women (aged 12-25 y) with surgically confirmed endometriosis and pelvic pain enrolled in a double-blind, randomized, placebo-controlled trial. The primary outcome was pain measured by the visual analog scale (VAS). Secondary outcomes were quality of life, pain catastrophizing, and pain medication usage. Participants were randomly assigned to receive 2000 IU vitamin D3, 1000 mg fish oil, or placebo daily for 6 mo. RESULTS A total of 147 women were screened and 69 were randomly assigned as follows: 27 to vitamin D3; 20 to fish oil; and 22 to placebo. Participants in the vitamin D arm experienced significant improvement in VAS pain [mean (95% CI) worst pain in the past month, from baseline to 6 mo: 7.0 (6.2, 7.8) to 5.5 (4.2, 6.8), P = 0.02]; however, an improvement of nearly identical magnitude was observed in the placebo arm [6.0 (5.1, 6.9) to 4.4 (3.0, 5.8), P = 0.07]. A more modest improvement was observed in the fish oil arm [5.9 (4.8, 7.0) to 5.2 (3.7, 6.8), P = 0.39]. Neither of the intervention arms were statistically different from placebo. CONCLUSIONS In young women with endometriosis, supplementation with vitamin D led to significant changes in pelvic pain; however, these were similar in magnitude to placebo. Supplementation with fish oil resulted in about half of the VAS pain reduction of the other 2 arms. Studies are needed to better define the physiology underlying the observed reduction in pain score in the placebo arm that persisted across 6 mo.This trial was registered at clinicaltrials.gov as NCT02387931.