Vitamin E for Male Infertility
Verdict: Disputed
Across 6 PubMed studies, the evidence for Vitamin E in Male Infertility grades Tier C — weak evidence. High-quality studies disagree — the evidence is genuinely mixed.
C 🟠 C Weak Evidence Disputed
Why this grade7-layer evidence engine
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Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.47
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Disputed
Confidence
70%
Broadly consistent
Evidence level
E1
Cochrane high-quality SR/MA
▸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 = 0.472
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 內部嚴重矛盾 (3 positive vs 2 negative，各 ≥2)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 1 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 Database of Systematic Reviews, 2022 update)
Finding: Across 90 RCTs of antioxidants as a class, live birth showed OR 1.43 (95% CI 1.07-1.91; 12 RCTs, 1283 men) but fell to a non-significant Peto OR 1.22 (95% CI 0.85-1.75; 8 RCTs, 827 men) after removing high-risk-of-bias trials, with the authors rating the evidence very low certainty and overall inconclusive.
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
Finding: In the broadest and most recent synthesis (50 included studies), no effect on pregnancy or live birth was found for dietary supplements overall, and vitamin E specifically showed no improvement in any sperm parameter, leading the authors to conclude there is no convincing evidence of benefit.
View on PubMed Effect of Antioxidants on Sperm Quality Parameters in Subfertile Men: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials
Finding: In a network meta-analysis of 18 RCTs (1790 subfertile men) comparing 8 antioxidants, vitamin E was not among the top-ranked agents, with CoQ10 most effective for sperm concentration and carnitine most effective for motility.
View on PubMed Effects of vitamin E and vitamin C on male infertility: a meta-analysis
Finding: Pooling 11 RCTs (832 patients), the vitamin E group had a higher spousal pregnancy rate than control (RR 1.86, 95% CI 1.02-3.41), and vitamin E/C improved progressive motility (SMD 0.38, 95% CI 0.22-0.55), concentration (SMD 0.21, 95% CI 0.09-0.34), morphology (SMD 0.32, 95% CI 0.09-0.55) and total sperm number (SMD 0.28, 95% CI 0.12-0.43) without notable adverse effects.
View on PubMed Effect of vitamin E on Semen Quality Parameters: A Meta-Analysis of a Randomized Controlled Trial
Finding: Across 8 RCTs (459 patients), vitamin E increased total sperm count (SMD 0.23, 95% CI 0.02-0.45, p=0.035) and improved forward motility in the >=6-month subgroup (SMD 0.80, 95% CI 0.46-1.14, p<0.001), but had no significant effect on sperm concentration (SMD 0.04, 95% CI -0.21 to 0.29, p=0.769) or total motility (SMD 0.20, 95% CI -0.01 to 0.42, p=0.061).
View on PubMed Influence of oral vitamin and mineral supplementation on male infertility: a meta-analysis and systematic review
Finding: This review of 18 double-blind placebo-controlled trials (7 pooled) found benefit for selenium, CoQ10, L-carnitine combinations, folic-acid+zinc and EPA+DHA, but reported no separate pooled effect estimate for vitamin E, so it provides only indirect, non-specific support for vitamin E.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Cautious
Some scientific evidence suggests that consumption of antioxidant vitamins 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
Cautious
The effect on blood clotting and associated increased risk of bleeding is considered as the critical effect to establish an UL for vitamin E. ... The ULs for vitamin E from all dietary sources, which were previously established by the Scientific Committee on Food, are retained for all population groups source↗
L4c UK NHS
Cautious
You should be able to get all the vitamin E you need from your diet. Taking 540mg (800 IU) or less a day of vitamin E supplements is unlikely to cause any harm. If you take vitamin E supplements, do not take too much as this could be harmful. source↗
L4d TW TFDA / 衛福部
Cautious
其維生素E之總含量不得高於400I.U.（268mg d-α-tocopherol） source↗
L4e WHO
Cautious
Vitamin E and C supplementation is not recommended for pregnant women to improve maternal and perinatal outcomes. source↗
L5a NIH Office of Dietary Supplements
Cautious
Clinical trials have not provided evidence that routine use of vitamin E supplements prevents cardiovascular disease or reduces its morbidity and mortality. source↗
L5c Cleveland Clinic
Neutral
things like vitamin C and vitamin E, L-carnitine, zinc 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↗