Calcium Alpha-Ketoglutarate for Bone Health
Calcium alpha-ketoglutarate (Ca-AKG) is not established for bone health. One small trial lowered a bone-resorption marker, but it did not significantly improve bone density, and no fracture data exist.
Why this grade7-layer evidence engine
The grade rests on thin human data. The only clinical trial (Filip 2007, PMID 17896582) randomized 76 postmenopausal women with osteopenia to AKG-calcium (6 g AKG plus 1.68 g calcium daily) versus calcium alone. The bone-resorption marker CTX fell about 37% at 24 weeks (p=0.006), but the between-group lumbar-spine bone-density difference (+0.9%) was not statistically significant, and no fracture outcomes were measured.
Supporting evidence is preclinical. In mice, AKG increased bone mass and slowed age-related loss via histone-methylation changes (Wang 2020, PMID 33154378), and a cell study showed AKG curbs osteoclast formation through NF-kB/PHD1 signaling (Tian 2023, PMID 36771407). These give a plausible mechanism but do not prove benefit in people.
Regulators and clinics do not endorse it. The US FDA treats Ca-AKG only as a DSHEA supplement ingredient that must follow GMP and avoid unverified therapeutic claims; the EU EFSA has not authorized it as a novel food; the UK NHS and WHO do not address it. With one small, unreplicated trial, a non-significant density endpoint, and a study dose (6 g/day) far above typical retail doses, the evidence stays Weak (Tier C). Calcium plus vitamin D and weight-bearing exercise remain the guideline-backed options.
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 = 0.523
- 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