Cod Liver Oil Toxicity: Vitamin A & D Overdose Risks

Cod liver oil provides omega‑3s (EPA/DHA) plus vitamins A and D. Toxicity arises from excessive vitamin A and D intake, not the fatty acids.

Vitamin A Toxicity (Hypervitaminosis A)

• UL (adults): 3,000 µg RAE/day (10,000 IU).
• 1 Tbsp cod liver oil ≈ 1,350 µg RAE (4,500 IU) – near UL if combined with diet/supplements.
• Acute: nausea, vomiting, headache, vertigo, blurred vision.
• Chronic: hepatotoxicity, bone pain, hypercalcemia, teratogenicity (pregnancy), skin desquamation.

Vitamin D Toxicity (Hypervitaminosis D)

• UL: 4,000 IU/day (100 µg).
• 1 Tbsp ≈ 1,360 IU.
• Hypercalcemia → nausea, polyuria, nephrocalcinosis, renal failure, cardiac arrhythmias.

Mercury & Contaminants

Reputable brands molecularly distill to remove mercury, PCBs, dioxins. Levels typically <0.1 ppm – well below safety limits.

Safe Use Guidelines

• Check total vitamin A/D from all sources (multivitamin, fortified foods, other supplements).
• Prefer separate omega‑3 (fish/algal oil) + targeted vitamin D3 if needed.
• Pregnancy: avoid high‑vitamin A cod liver oil; use prenatal with β‑carotene (safe provitamin A).
• Dose: 1 tsp (5 mL) daily often sufficient for omega‑3s; don’t exceed label.