A traditionally prepared whole-food oil supplying marine fats, ready-made vitamin A, some vitamin D and a little vitamin K. No human study has tested the fermented product. Ordinary cod liver oil lets people with inflammatory joint disease use less painkiller. Against that sits the build-up of ready-made vitamin A, linked to hip fracture — and this product declares no amount. (Full Review)
| Marker | Target | Why |
|---|---|---|
| 25-hydroxyvitamin D | 40–60 ng/mL (100–150 nmol/L) | Shows whether the undeclared vitamin D fraction contributes anything |
| Serum retinol | 40–60 µg/dL (1.4–2.1 µmol/L) | The vitamin A fraction is the main long-term hazard |
| Fasting retinyl esters | Below 10% of total vitamin A | The one test that detects vitamin A overload before symptoms |
| Omega-3 index | 8–12% of red-cell fatty acids | Confirms the marine fraction is actually delivered and absorbed |
| Albumin-corrected serum calcium | 9.0–9.8 mg/dL | High blood calcium is the commonest presenting sign of vitamin A excess |
| Alanine aminotransferase (ALT) | 10–26 U/L women, 10–30 U/L men | Vitamin A is directly toxic to the liver at cumulative doses |
| International normalised ratio (INR) | 2.0–3.0 for most warfarin indications | The omega-3 and vitamin K2 fractions pull the clotting time in opposite directions |
Cadence: Baseline before the first serving; vitamin D status, retinol and calcium at 12 weeks; then every 6–12 months if values sit in range, with liver enzymes annually. Anyone on an anticoagulant adds a clotting check at 4 weeks and after any dose change.