Cod liver oil from Iceland supplies long-chain omega-3s (EPA/DHA) and fat-soluble vitamins A and D. It has historical use for rickets and current uses for omega-3 intake and vitamin D supplementation. Product nutrient levels and purification vary; verify labels and choose third-party tested brands. Pregnant people should avoid excess vitamin A and consult a provider before using.

What Icelandic cod liver oil is

Cod liver oil is the oil pressed from the livers of Atlantic cod. Icelandic brands come from the North Atlantic and are valued because they provide long-chain omega-3 fatty acids (EPA and DHA) plus preformed vitamins A (retinol) and D. Unlike standard fish-oil supplements, cod liver oil supplies both omega-3s and fat-soluble vitamins.

Short history

Cod liver oil was widely used in Europe beginning in the 18th century to treat rickets, a bone-softening disease caused by vitamin D deficiency. That historic use helped establish cod liver oil as a dietary supplement for vitamin D and general nutrition.

Nutrients and what the evidence shows

Cod liver oil supplies EPA and DHA, which support heart and metabolic health in specific contexts. Supplement omega-3s can lower triglyceride levels; prescription high-dose EPA formulations have shown cardiovascular benefit in select trials. Evidence for broad prevention of heart disease from over-the-counter fish or cod liver oil remains mixed.

DHA is important for fetal brain and eye development, and many health authorities recommend pregnant and nursing people consume adequate DHA from diet or supplements. However, because cod liver oil contains preformed vitamin A (retinol), pregnant people should be cautious: excess retinol can be harmful in pregnancy. Check the vitamin A dose on the label and compare with recommended limits.

Typical amounts of EPA, DHA, vitamin A and vitamin D in commercial Icelandic cod liver oils vary by product and concentration; check the product label for exact values.

Safety, contaminants and testing

Reputable manufacturers test for contaminants such as heavy metals, PCBs and dioxins and refine oil to meet food-safety standards. Still, quality and testing protocols vary by producer and country; inspect third-party testing or certifications when possible. 1

Two general safety points:


  • Vitamin A: The tolerable upper intake level for preformed vitamin A (retinol) for adults is established by health authorities; exceeding that level - especially during early pregnancy - can be risky. Always total vitamin A from all sources.


  • Vitamin D: Cod liver oil can contribute meaningful vitamin D, but amounts differ by brand. Avoid combining high-dose vitamin D supplements without medical advice.


Choosing and using cod liver oil


Read labels to compare EPA/DHA and vitamin A/D content. Choose brands with third-party purity testing and clear dosage guidance. If you are pregnant, nursing, taking blood thinners, or managing a chronic condition, consult your healthcare provider before starting cod liver oil.

Bottom line

Icelandic cod liver oil is a combined source of EPA/DHA and vitamins A and D. It can help meet dietary needs but requires label checks for nutrient amounts and caution in pregnancy or when taking other supplements or medications.
  1. Verify typical EPA/DHA and vitamin A/D content ranges per serving in commercial Icelandic cod liver oil products and update label guidance accordingly.
  2. Confirm common testing standards and certifications used by Icelandic cod liver oil producers and cite examples if available.
  3. Verify population-level claims about Icelandic longevity or lower heart-disease rates before reintroducing any comparative statements.

FAQs about Icelandic Cod Liver Oil

How is cod liver oil different from regular fish oil?
Cod liver oil comes from the fish's liver and contains preformed vitamins A and D in addition to EPA and DHA. Regular fish oil is usually derived from muscle tissue and supplies mainly EPA and DHA without the added vitamins.
Can pregnant people take cod liver oil?
Pregnant people can benefit from DHA, but cod liver oil often contains preformed vitamin A (retinol), which at high doses may be harmful in pregnancy. Check the vitamin A content on the label and consult your healthcare provider before taking it.
Does cod liver oil prevent heart disease?
Cod liver oil provides omega-3s that can lower triglycerides. Evidence that over-the-counter cod liver oil prevents heart disease in the general population is mixed; certain prescription omega-3 products have shown benefit in specific patient groups.
Are there safety concerns with contaminants?
Reputable manufacturers test and refine oils to reduce contaminants (heavy metals, PCBs, dioxins). Quality varies by brand, so look for third-party testing or certifications on the product.
How do I choose a quality product?
Compare EPA/DHA and vitamin A/D amounts on the label, choose brands with third-party purity testing, and consult a clinician if you are pregnant, breastfeeding, on medications, or have chronic conditions.