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Cod liver oil

A traditional two-in-one — omega-3 plus vitamins A and D, with a vitamin-A ceiling to respect.

Reviewed by Bodil Isaksson, Licensed Biomedical Scientist (Sweden)Last reviewed July 2026Supplement guide

SupplementsFatty acidsOmega-3Vitamins

Cod liver oil is an old-fashioned tonic that’s still useful: it supplies EPA/DHA along with fat-soluble vitamins A and D — the reason it once prevented rickets.

Key takeaways

  • Provides omega-3 (EPA/DHA) plus vitamin A and vitamin D.
  • A handy source of vitamin D in low-sun winters.
  • Watch total vitamin A — don’t stack with other high-A supplements, and use caution in pregnancy (excess vitamin A is harmful).
  • Lower in EPA+DHA than concentrated fish oil.

What it is

Oil from cod livers, naturally rich in the fat-soluble vitamins A and D as well as omega-3s.

The evidence

Historically it eliminated rickets via vitamin D, and it remains a reasonable combined source of omega-3 and vitamin D. Its EPA+DHA content is modest, so it’s not the most efficient pure omega-3.

Dose & safety

Follow the label and tally your vitamin A from all sources to stay within safe limits. In pregnancy, avoid high-dose vitamin A — choose a low-A or plain omega-3 instead.

Who benefits

People wanting omega-3 + winter vitamin D in one, who aren’t already taking high-dose vitamin A.

Bottom line: a sensible omega-3-plus-vitamin-D option for winter — just keep an eye on total vitamin A, especially in pregnancy.

References

Adult research summary for education, not a prescription.

  1. Cod liver oil: omega-3 with vitamins A and D — overview. www.barebiology.com

This article summarises nutrition science for education. It is not a substitute for individual medical advice; consult a professional before starting a supplement, in pregnancy, or alongside medication.