Manganese for Bone Fracture

Verdict: No reliable evidence manganese prevents fractures

There is no reliable human evidence that manganese supplements prevent or heal bone fractures; the verdict reflects an evidence gap (Unverified), not proof of benefit, and high-dose manganese carries a genuine neurotoxicity risk.

U ⚫ U Unverified Insufficient Evidence

🔬Why this grade7-layer evidence engine

This claim is graded Unverified / Insufficient Evidence because the human evidence base for the fracture endpoint is essentially empty. PubMed contains no randomized trial of manganese alone with fractures as an outcome. The most-cited study, Strause 1994 (PMID 8027856, n=59), tested a calcium-plus-trace-mineral blend (zinc, manganese, copper), measured spinal bone mineral density rather than fractures, was industry-funded and underpowered, and cannot isolate any manganese-specific effect.

Supporting reviews reinforce the gap rather than fill it. A narrative review of manganese in human nutrition (PMID 8074260) notes that documented manganese deficiency in people is extremely rare and that no human trial has tested isolated manganese on fractures, while a 2023 review of trace elements in osteoporosis (PMID 37371586) explicitly cautions against extrapolating combination-formula benefits to single-mineral supplements. NHANES cross-sectional data (PMID 36269752, n=1,496) show only a non-linear, U-shaped serum-manganese-to-BMD association that cannot prove cause or justify supplementation.

Regulators and clinics treat manganese only as an essential nutrient, not a fracture therapy. The FDA lists it as a nutrient supplement with no approved health claim, and EFSA's generic 'maintenance of normal bones' wording sits alongside its 2023 decision to cut the adult tolerable upper intake to 3 mg/day over neurotoxicity concerns. The NHS and WHO are cautious, warning that high long-term doses can cause nerve damage (manganism). Clinical bodies (NIH ODS, Mayo, Harvard, orthopedic societies) do not endorse manganese for fractures, leaving no proven benefit set against a real safety ceiling.

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Scoring transparency

All scores computed by a 7-layer evidence engine — fully auditable

Raw score 0.45

← counter-evidence / ineffectiveeffective / strong evidence →

Final grade

U · Insufficient Evidence

Confidence

69%

Broadly consistent

Evidence level

Single high-quality meta-analysis

How strongly each layer supports this effect

lower = less supportive

L11 AI re-checkIndependent read

0.20

L2 PubMedPrimary literature

0.45

L3 MechanismPlausibility

0.45

L1 ExamineGlobal benchmark

0.50

L5 Clinical bodiesAuthoritative stance

0.62

Against Mixed Supports

▸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 = 0.448
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 — | C→U 因 scope.conflation_risk=true 且 L11 獨評較低 (B7-2 tier cap)
detect_disputes — 偵測到 0 個 hard + 1 個 soft dispute
decide_status — 依 tier + dispute 結果決定 status

📄PubMed studies (4)L2 · primary research & systematic reviews

Spinal bone loss in postmenopausal women supplemented with calcium and trace minerals

PMID: 8027856 1994 隨機對照試驗 n = 59

Finding: Only the Ca + trace minerals combination arm significantly attenuated spinal bone loss vs placebo; the Ca-alone arm did not reach significance, and the trace-mineral-alone arm (Zn+Mn+Cu) showed numeric but non-significant attenuation. The trial cannot isolate the manganese contribution from zinc and copper, and fractures were not an endpoint. Frequently cited as the basis for adding manganese to bone formulas despite no isolated-manganese effect being demonstrated.

🟠 Limited quality ⚠️ Industry-funded

View on PubMed

Trace elements in human nutrition: manganese

PMID: 8074260 1994 Other

Finding: Documented manganese deficiency in humans is extremely rare; experimental short-term depletion in metabolic-ward studies produced biochemical changes but no documented fractures. Animal data show manganese is required for proteoglycan and chondroitin sulfate synthesis in bone matrix, but no human RCT has tested isolated manganese supplementation on fracture outcomes.

Effect size: n/a (narrative; no human fracture data with isolated manganese)

View on PubMed

The Role of Trace Elements and Minerals in Osteoporosis: A Review of Epidemiological and Laboratory Findings

PMID: 37371586 2023 統合分析

Finding: Authors conclude evidence for manganese as an isolated intervention for bone outcomes is sparse and limited to combination trials (notably Strause 1994) and observational serum/intake correlations. No included study used manganese alone, and no fracture-endpoint RCT for manganese was identified. Authors caution against extrapolating combination-arm benefits to single-mineral supplementation.

Effect size: n/a (no pooled estimate for manganese alone possible)

View on PubMed

Relationship between blood manganese and bone mineral density and bone mineral content in adults: A population-based cross-sectional study

PMID: 36269752 2022 Other n = 1,496

Finding: Cross-sectional inverse U-shaped association reported between serum manganese and BMD in some subgroups, with both very low and very high serum manganese associated with lower BMD. The design cannot establish causality or supplementation effect, and fractures were not assessed.

🟠 Limited quality Government Effect size: Non-linear association with BMD (observational); not translatable to fracture risk reduction by supplementation

View on PubMed

🏛️Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …

L4a US FDA

Supportive

NUTRIENT SUPPLEMENT source↗

L4b EU EFSA

Supportive

contributes to normal energy-yielding metabolism; contributes to the maintenance of normal bones; contributes to the normal formation of connective tissue; contributes to the protection of cells from oxidative stress source↗

L4c UK NHS

Cautious

You should be able to get all the manganese you need from your daily diet. Taking high doses of manganese for long periods of time might cause muscle pain, nerve damage and other symptoms, such as fatigue and depression. For most people, taking 4mg or less of manganese supplements a day is unlikely to cause any harm. For older people, who may be more sensitive to manganese, taking 0.5mg or less… 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，其錳之總含量不得高於11 mg。限於補充食品中不足之營養素時使用。 source↗

L4e WHO

Cautious

A provisional guideline value of 0.08 mg/L for manganese in drinking-water is established based on neurological effects in rats; emerging evidence supports the oral route as a potentially important route of exposure for manganese toxicity. source↗

L5a NIH Office of Dietary Supplements

Cautious

Manganese is an essential trace element that is naturally present in many foods and available as a dietary supplement. Manganese is a cofactor for many enzymes, including manganese superoxide dismutase, arginase, and pyruvate carboxylase. Through the action of these enzymes, manganese is involved in amino acid, cholesterol, glucose, and carbohydrate metabolism; reactive oxygen species scavengin… source↗

L5c Cleveland Clinic

Supportive

one of the minerals important for growing and maintaining healthy bones source↗

✓PMID 100% verifiedevery citation checked via NCBI Entrez

🔬4 PubMed studiesindependently re-checked by multiple sub-agents

engine_version: v1.0 claim_id: CLM-COND-bone-fracture-INT-manganese-001 繁體中文版 →