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Head-to-head evidence comparison — which supplement is right for you?
Vitamin B6 wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
18 of 23 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
9 of 11 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Selenium and Vitamin B6 have evidence — compare verdict strength side-by-side.
100-200mcg
With food
Selenomethionine (best absorbed)
25-100mg daily
Morning with food, Can take with other B vitamins
P-5-P (Pyridoxal-5-Phosphate)
4-8 weeks
4-8 weeks
2-4 weeks
1-2 cycles
Months of high doses
Selenium, antioxidants, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis of randomized controlled trials
The American journal of clinical nutrition (2020) · Meta analysis · n=9423
However, a decreased risk with antioxidant mixtures was seen for CVD mortality when selenium was part of the mix (RR: 0.77; 95% CI: 0.62, 0.97; P = 0.02), with no association when selenium was absent.
Selenium for preventing cancer
The Cochrane database of systematic reviews (2018) · Meta analysis · n=27232
For analyses of RCTs with low risk of bias, the summary risk ratio (RR) for any cancer incidence was 1.01 (95% confidence interval (CI) 0.93 to 1.10; 3 studies, 19,475 participants; high-certainty evidence).
Selenium and prostate cancer: systematic review and meta-analysis
The American journal of clinical nutrition (2012) · Meta analysis · n=13254
Three high-quality studies included in the meta-analysis of toenail selenium and cancer risk indicated a reduction in prostate cancer risk (estimated RR: 0.29; 95% CI: 0.14, 0.61) with a toenail selenium concentration between 0.85 and 0.94 μg/g.
Dosage exploration of combined B-vitamin supplementation in stroke prevention: a meta-analysis and systematic review
The American journal of clinical nutrition (2024) · Meta analysis · n=76664
In areas without and with partial folic acid fortification, combined B-vitamin supplementation significantly reduced the risk of stroke by 34% [RR: 0.66; 95% confidence interval (CI): 0.50, 0.86] and 11% (RR: 0.89; 95% CI: 0.79, 1.00), respectively.
Vitamin and mineral supplementation for maintaining cognitive function in cognitively healthy people in mid and late life
The Cochrane database of systematic reviews (2018) · Meta analysis · n=83000
We found that giving B vitamin supplements to cognitively healthy adults, mainly in their 60s and 70s, probably has little or no effect on global cognitive function at any time point up to 5 years (SMD values from -0.03 to 0.06) and may also have no effect at 5-10 years (SMD -0.01).
Drug Efficacy in the Treatment of Antipsychotic-Induced Akathisia: A Systematic Review and Network Meta-Analysis
JAMA network open (2024) · Meta analysis · n=492
No association between effect sizes and psychotic severity was found.
Based on Cochrane systematic review showing moderate-certainty evidence for TPO antibody reduction. Effects on thyroid hormone levels (TSH, T4, T3) were inconsistent across studies.
Based on systematic review of nutritional interventions for PMS psychological symptoms. Evidence quality limited by study heterogeneity and need for more consistent protocols.
AI-estimated from published studies. Interpret as directional guidance.
Vitamin B6 has a higher evidence score (9/10 vs 9/10) and wins in 2 of 3 categories.
For prenatal support, Vitamin B6 has a higher relevance score (88 vs 72).
No known interactions between Selenium and Vitamin B6 have been documented in our database. However, always consult a healthcare provider before combining supplements.