What a 2016 placebo-controlled trial found about vitamin B6 for mastalgia
This archive entry covers a 2016 randomized double-blind trial conducted in Semnan, Iran, comparing vitamin B6 with placebo for mastalgia. It also summarizes how later evidence has affected interpretation of the findings.
What the study did and found
Published in Koomesh (2016), the trial by Setareh Soltany, Jafar Alavy Toussy, Hamidreza Hemmaty and Enayatollah Gholamaliyan enrolled 126 patients with breast pain at two hospitals in Semnan.
Participants received either vitamin B6 (100 mg twice daily) or placebo for two months. Daily pain charts recorded pain intensity and days with severe symptoms. Mean pain scores and severe-pain frequency declined significantly in both groups. Pain also decreased during the first five days in both groups, which the investigators associated with reassurance. No adverse effects were observed during the trial. The authors concluded that vitamin B6 was effective, while acknowledging the contribution of reassurance.
Why it is cited
The study is among the limited placebo-controlled trials included in later reviews of pyridoxine for mastalgia. A 2025 systematic review and meta-analysis included it in assessing whether vitamin B6 reduces breast pain beyond placebo.
The 2025 review pooled three placebo-controlled studies and reported no statistically significant benefit over placebo (SMD −3.57; 95% CI −9.15 to 2.01). Its evidence certainty was rated very low because of bias concerns, imprecision and substantial heterogeneity.
These findings temper the original positive conclusion. Improvement within the vitamin B6 group cannot alone establish efficacy when placebo recipients also improve. Available controlled evidence therefore does not reliably demonstrate that vitamin B6 provides greater mastalgia relief than placebo.
The topic today
Differences in dosage, treatment duration and pain measurement complicate comparisons across trials. Larger, better-designed studies are needed to clarify effectiveness.
The 2016 trial used 200 mg of vitamin B6 daily. By comparison, the U.S. adult tolerable upper intake level is 100 mg/day, and the European Food Safety Authority set an adult limit of 12 mg/day in 2023, reflecting concerns about peripheral neuropathy from excess intake. These general limits do not directly define supervised therapeutic dosing, but the trial's short-term absence of reported adverse effects does not establish the safety of unsupervised high-dose supplementation.