Vitamin E for NAFLD / MASLD
For non-diabetic adults with biopsy-confirmed NASH, vitamin E at 800 IU/day modestly improves liver inflammation and fat on biopsy and lowers liver enzymes, but it does not reverse fibrosis and is not supported for general fatty liver, people with diabetes, children, or those with cirrhosis.
Why this grade7-layer evidence engine
The grade rests on two consistent meta-analyses plus one anchor trial. PIVENS (PMID 20427778), a 247-patient randomized trial, found 800 IU/day improved liver histology in 43% of patients versus 19% on placebo (p=0.001), benefiting steatosis, lobular inflammation, ballooning, and ALT/AST. Meta-analyses pooling ~794 patients (PMID 37686767) and adult NAFLD trials (PMID 32810309) confirm meaningful ALT reductions of roughly 7 to 13 IU/L. The effect is real but modest, which is why it lands at preliminary rather than strong evidence.
Crucially, the benefit is narrow. No trial (PIVENS; TONIC, PMID 21521847; Bril, PMID 31332029) improved fibrosis, the feature most tied to long-term liver outcomes. In type 2 diabetes, vitamin E monotherapy failed its endpoint (31% vs 19%, p=0.26; PMID 31332029). The pediatric TONIC trial missed its primary ALT endpoint (26% vs 17%, p=0.26), with NASH resolution only a secondary finding. AASLD 2023 guidance (PMID 36727674) therefore recommends it only for non-diabetic, biopsy-proven NASH without cirrhosis.
Safety drives the warning. FDA, EFSA, NHS, WHO, and Mayo Clinic all caution that high-dose vitamin E raises bleeding and hemorrhagic-stroke risk, and the SELECT trial linked it to a higher prostate cancer signal (HR 1.17). The 800 IU therapeutic dose exceeds EFSA's 300 mg/day upper limit, so AASLD requires a physician-led risk discussion before starting and excludes people with diabetes or cirrhosis and those without biopsy-confirmed NASH.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸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 = 0.69
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (2 篇 > 0 negative)
- 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