Manganese for Micronutrient Deficiency
Manganese supplements are not a meaningful treatment for "micronutrient deficiency" in the general population, because dietary manganese deficiency has never been convincingly documented in otherwise healthy people. The only genuine human deficiency states are extreme experimental restriction and a rare inborn genetic disorder, so the evidence rates as weak (Tier C).
Why this grade7-layer evidence engine
The grade is weak because there is essentially no condition to treat. A controlled depletion study in young men (PMID 3819860, n=7) had to restrict intake to about 0.11 mg/day for five weeks to produce only negative balance and a transient rash, with no neurological, blood, or growth syndrome. Narrative and mechanistic reviews (PMID 27264059, PMID 25982296) conclude dietary manganese deficiency has never been convincingly documented in free-living healthy people, since typical diets supply more than enough via tea, whole grains, nuts, and leafy vegetables.
The only well-characterized human deficiency is the rare genetic SLC39A8 transport disorder (PMID 26637979, n=4), where high-dose oral manganese partially corrects glycosylation and symptoms. That proves true deficiency is reversible but applies to a vanishingly rare inborn population, not ordinary supplement users. A parenteral-nutrition review (PMID 28452962) likewise found clinical deficiency rare even when manganese is omitted, while manganese excess (manganism) is the dominant concern.
Regulators reinforce the cautious read. The FDA lists manganese only as a GRAS nutrient supplement with no approved health claim, and while EFSA permits generic claims (energy metabolism, bones, connective tissue, antioxidant protection) it lowered the safe upper limit to 3 mg/day. The NHS and WHO stress getting manganese from food and warn that high long-term doses risk nerve damage, so routine supplementation is not supported.
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 = 0.464
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 無高階證據可裁決
- 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