Vitamin K for Arthritis

Verdict: Insufficient Evidence

Across 4 PubMed studies, the evidence for Vitamin K in Arthritis grades Tier U — unverified / insufficient. Research is still too limited to draw a firm conclusion.

U ⚫ U Unverified Insufficient Evidence

🔬Why this grade7-layer evidence engine

⚖️

Scoring transparency

All scores computed by a 7-layer evidence engine — fully auditable
Raw score 0.41
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
U · Insufficient Evidence
Confidence
74%
Broadly consistent
Evidence level
E6
Multiple smaller RCTs (n<500)

How strongly each layer supports this effect

lower = less supportive
L11 AI re-checkIndependent read
0.20
L2 PubMedPrimary literature
0.40
L1 ExamineGlobal benchmark
0.50
L3 MechanismPlausibility
0.50
L5 Clinical bodiesAuthoritative stance
0.55
Against Mixed Supports
View the full decision path (audit trail)
  1. compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.407
  2. tier_from_score — 依分數區間映射至 tier letter
  3. apply_hec_rules — 無高階證據可裁決
  4. tier_strict_requirement_check — Tier 條件達標,未降階
  5. detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
  6. decide_status — 依 tier + dispute 結果決定 status

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

Low vitamin K status is associated with osteoarthritis in the hand and knee (Framingham Offspring)
PMID: 18759320 2008 Cross-sectional n = 672
Finding: Low plasma phylloquinone associated with higher prevalence of hand osteophytes (OR 1.56, 95% CI 1.08-2.24) and knee osteophytes (OR 2.39, 95% CI 1.05-5.40); cross-sectional, no causal inference.
Government Effect size: OR 1.56 (hand osteophytes); OR 2.39 (knee osteophytes)
View on PubMed
Vitamin K in hand osteoarthritis: results from a randomised clinical trial
PMID: 18625626 2008 RCT (double-blind) n = 378
Finding: No significant overall effect on hand OA radiographic progression vs placebo; pre-specified subgroup of vitamin-K-insufficient participants who became replete showed less JSN progression (post-hoc, exploratory).
🟢 High quality Government Effect size: Overall null; subgroup post-hoc only
View on PubMed
The association between vitamin K status and knee osteoarthritis features in older adults: the Health, Aging and Body Composition Study.
PMID: 25528106 2015 Cohort n = 1,180
Finding: Plasma phylloquinone <0.5 nmol/L associated with greater prevalence of cartilage lesions (OR 1.60, 95% CI 1.07-2.39) and meniscus damage (OR 2.61, 95% CI 1.32-5.16); observational only.
Government Effect size: OR 1.60 cartilage; OR 2.61 meniscus
View on PubMed
Vitamin K2 administration is associated with decreased disease activity in patients with rheumatoid arthritis
PMID: 23124653 2013 RCT (open-label) n = 56
Finding: Modest reductions in DAS28 and MMP-3 vs DMARD alone in this small open-label pilot; no blinding, no placebo, hypothesis-generating only.
🟠 Limited quality
View on PubMed

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

L4a US FDA
Supportive
Vitamin K1 Injection is indicated for prophylaxis and treatment of vitamin K-deficiency bleeding in neonates source↗
L4b EU EFSA
Supportive
a cause and effect relationship has been established between the dietary intake of vitamin K and normal blood coagulation ... and the maintenance of normal bone source↗
L4c UK NHS
Cautious
You should be able to get all the vitamin K you need by eating a varied and balanced diet. Any vitamin K your body does not need immediately is stored in the liver for future use, so you do not need it in your diet every day. source↗
L4d TW TFDA / 衛福部
Supportive
成年男性 120 微克/日,女性 90 微克/日(足夠攝取量 AI) source↗
L4e WHO
Supportive
vitamin K1 should be given to all newborns as a single, intramuscular dose of 0.5–1 mg source↗
L5a NIH Office of Dietary Supplements
Supportive
Vitamin K, the generic name for a family of compounds with a common chemical structure of 2-methyl-1,4-naphthoquinone, is a fat-soluble vitamin source↗
L5e Specialty Society (condition-mapped)
Neutral
Other research suggests eating vitamin K-rich veggies like broccoli, spinach, lettuce, kale and cabbage dramatically reduces inflammatory markers in the blood. 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-arthritis-INT-vitamin-k-001 繁體中文版 →