Legacy AI grade · Sources dated 2026-06-09. Not expert reviewed. Coverage is limited to the listed sources. About the new summary workflow
Selenium for Male Infertility
Verdict: Published with Warning
Across 6 PubMed studies, the evidence for Selenium in Male Infertility grades Tier C — weak evidence. Effective, but with safety or population caveats.
C 🟠 C Weak Evidence Published with Warning
Why this grade7-layer evidence engine
Selenium for male infertility lacks a selenium-specific Cochrane anchor. PMID 35506389 pools mixed antioxidants for subfertility, not selenium alone.
Combination trials dominate: PMID 19091331 tests selenium+NAC (expression-of-concern noted); PMID 21403799 is selenium+vitamin E cohort data. Three selenium-inclusive MAs exceed the E1 label.
Tier C reflects surrogate semen parameters without pregnancy/live-birth outcomes. Do not market selenium as proven fertility treatment outside deficiency contexts.
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.63
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Published with Warning
Confidence
85%
Highly consistent evidence
Evidence level
E3
Cochrane 35506389 is multi-antioxidant not selenium-specific
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.629
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 negative 主導 (2 negative > 0 positive)，下層 RCT 不能推翻
- apply_hec_override — HEC-1 高階證據 negative — 強制由 B 改為 D
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (6)L2 · primary research & systematic reviews
Antioxidants for male subfertility (Cochrane Review, CD007411.pub5)
Finding: Across 90 RCTs of 20 oral antioxidants (selenium one of them, not separately pooled), antioxidants MAY increase live birth (OR 1.43, 95% CI 1.07-1.91, P=0.02, 12 RCTs/1283 men) but this lost significance after removing high-risk-of-bias studies (OR 1.22, 95% CI 0.85-1.75, P=0.27); GRADE very-low certainty for live birth.
View on PubMed The Effect of Dietary Supplements on Male Infertility in Terms of Pregnancy, Live Birth, and Sperm Parameters: A Systematic Review and Meta-Analysis (Nutrients)
Finding: Found NO effect of any dietary supplement on pregnancy or live birth; selenium improved only total motility (MD +15.25%, 95% CI 11.71-18.80, I2=0%) with no effect on sperm concentration (MD +6.32 x10^6/mL, 95% CI -14.88 to 27.51); certainty of evidence generally low/very-low.
View on PubMed Effect of Antioxidants on Sperm Quality Parameters in Subfertile Men: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials (Adv Nutr)
Finding: Selenium was NOT significantly superior to placebo on any parameter; CoQ10 ranked best for concentration (MD +5.95, 95% CI 0.05-10.79; SUCRA 79.4%) and carnitine best for motility (MD +12.43, 95% CI 4.07-20.26; SUCRA 88.7%), with selenium outranked on every endpoint.
View on PubMed The Effect of Nutrients and Dietary Supplements on Sperm Quality Parameters: A Systematic Review and Meta-Analysis of Randomized Clinical Trials (Adv Nutr)
Finding: Selenium produced small but significant improvements in sperm concentration (MD +3.91 x10^6/mL, 95% CI 3.08-4.73), total motility (MD +3.30%, 95% CI 2.95-3.65) and morphology (MD +1.87%, 95% CI 1.50-2.24), but authors caution results from small studies with high heterogeneity and no pregnancy/live-birth data.
View on PubMed Efficacy of selenium and/or N-acetyl-cysteine for improving semen parameters in infertile men: a double-blind, placebo controlled, randomized study (J Urol) [EXPRESSION OF CONCERN, PMID 36626340]
Finding: All semen parameters improved significantly with selenium and NAC (additive when combined), with strong correlation between combined seminal Se+NAC concentration and sperm concentration (r=0.67, P=0.01), motility (r=0.64, P=0.01) and morphology (r=0.66, P=0.01); HOWEVER the article carries a 2023 Journal of Urology Expression of Concern, so reliability is uncertain.
View on PubMed Selenium-vitamin E supplementation in infertile men: effects on semen parameters and pregnancy rate (Int J Gen Med)
Finding: 52.6% (362/690) showed improved motility/morphology and 10.8% (75/690) achieved spontaneous pregnancy, with mean semen-parameter change +4.3% (SD 4.29; paired t-test P<=0.001), but the design is uncontrolled (no concurrent placebo arm), so causal/comparative inference is weak.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Cautious
Selenium may reduce the risk of certain cancers. Some scientific evidence suggests that consumption of selenium may reduce the risk of certain forms of cancer. However, FDA has determined that this evidence is limited and not conclusive. source↗
L4b EU EFSA
Supportive
Selenium contributes to normal thyroid function; contributes to the normal function of the immune system; contributes to the protection of cells from oxidative stress; contributes to normal spermatogenesis; contributes to the maintenance of normal hair; contributes to the maintenance of normal nails. source↗
L4c UK NHS
Cautious
75μg a day for men (19 to 64 years); 60μg a day for women (19 to 64 years). You should be able to get all the selenium you need by eating a varied and balanced diet that includes meat, fish or nuts. Taking 350μg or less a day of selenium supplements is unlikely to cause any harm. Too much selenium causes selenosis, a condition that, in its mildest form, can lead to loss of hair and nails. source↗
L4d TW TFDA / 衛福部
Supportive
形態屬膠囊狀、錠狀且標示有每日食用限量之食品，在每日食用量中，其硒之總含量不得高於200 μg。限於補充食品中不足之營養素時使用。 source↗
L4e WHO
Supportive
Prophylaxis consisting of oral administration of selenium 3 months before the periods of highest anticipated risk is highly effective. Once the disease is established, selenium is of little or no therapeutic value. source↗
L5a NIH Office of Dietary Supplements
Cautious
Selenium is a trace element that is naturally present in many foods, added to others, and available as a dietary supplement. Selenium, which is nutritionally essential for humans, is a constituent of more than two dozen selenoproteins that play critical roles in reproduction, thyroid hormone metabolism, DNA synthesis, and protection from oxidative damage and infection. source↗
L5c Cleveland Clinic
Cautious
Male oxidative stress infertility (MOSI) [when reactive oxygen species outnumber antioxidants] is really the only condition that can be treated effectively with male fertility supplements. ... For them, taking supplemental antioxidants for three months or longer can improve sperm parameters. ... If a patient doesn't have MOSI, however, taking antioxidants may do more harm than good. ... Ironica… source↗
L5e Specialty Society (condition-mapped)
Cautious
Clinicians should counsel patients that the benefits of supplements (e.g., antioxidants, vitamins) are of questionable clinical utility in treating male infertility. Existing data are inadequate to provide recommendation for specific agents to use for this purpose. (Moderate Recommendation; Evidence Level: Grade B) source↗