Reviewed and updated: 21 October 2026
Should I take cod liver oil or omega-3? For most adults, a plain omega-3 fish oil is the simpler, easier-to-control choice, because cod liver oil brings a lot of vitamin A along with its omega-3, and vitamin A is the one nutrient here you can easily overdo. I have a lot of respect for the cod liver oil tradition, so let me walk you through what each one gives you and how to decide.
Should I take cod liver oil or omega-3? The quick answer
- Cod liver oil is a fish oil from cod livers. It contains some EPA and DHA, plus naturally occurring vitamins A and D.
- Omega-3 fish oil is made for its EPA and DHA, usually at a higher strength per serving and with no added vitamin A.
- Most people need one, not both. The thing to watch is total vitamin A across everything you take, not the omega-3.
- The one caution: if you are pregnant or trying to conceive, fish liver oils are generally best avoided, so ask your midwife or GP.
A little heritage: why cod liver oil still has a place
Cod liver oil is one of the oldest supplements in the British cupboard. Coastal communities around the North Atlantic, and Norway in particular, pressed oil from cod livers for generations, and it became a household staple here for decades, often given by the spoonful. People reached for it because it was a simple, concentrated source of the fat-soluble vitamins A and D, plus omega-3, from a food the sea provided.
That heritage is genuine, and so is its main trade-off. The same liver that holds those vitamins holds a lot of preformed vitamin A, which is why modern guidance is more careful about it than earlier generations were.
What omega-3 actually is: ALA, EPA and DHA
“Omega-3” is a family of fats. ALA comes from plants such as flaxseed and walnuts, and the body converts only a small amount of it into the two long-chain forms that matter most, EPA and DHA. Those two come directly from oily fish and algae. EPA and DHA contribute to the normal function of the heart at a daily intake of 250 mg, and DHA contributes to the maintenance of normal brain function and normal vision at 250 mg a day. I go through the difference between the two in EPA vs DHA and how much you need, and the full picture is in our omega-3 for heart and brain health guide.
What cod liver oil contains that standard fish oil does not
The headline difference is vitamins. A typical cod liver oil capsule lists vitamin A (as retinol, the preformed form) and vitamin D on the label, and the amounts vary a lot between brands, so read yours rather than assuming. The second difference is concentration. Because cod liver oil is a whole-oil product, the EPA and DHA often make up a smaller share of each capsule than in a concentrated fish oil, so you may need several capsules to reach the same EPA and DHA a single serving of a high-strength oil provides.
That is not a flaw, just a different product. If you want vitamin D, there is a cleaner way to cover it on its own, which I cover in vitamin D in winter in the UK. If you want EPA and DHA, a standard omega-3 oil gets you there without the vitamin A question. Our own Omega-3 Fish Oil gives 1,040 mg EPA and 692 mg DHA in a serving of two softgels, and contains no added vitamin A.
Our pick for this guide
Want a straightforward omega-3 and no vitamin A to count?
Omega-3 Fish Oil High Strength EPA & DHA: 1,040 mg EPA and 692 mg DHA in a two-softgel serving. A food supplement, not a replacement for medical advice. Contains fish (anchovies).
From £9.55 · 60 softgels (30 days)
Shop Omega-3 Fish Oil →The vitamin A sum: why it matters
Adults aged 19 to 64 need around 700 µg of vitamin A a day (men) or 600 µg (women), and most of us can get that from food. According to the NHS, some research suggests that having more than an average of 1.5 mg (1,500 µg) a day over many years may affect bones, making fractures more likely in later life, and it names fish liver oil, many multivitamins and liver or liver pâté as the usual ways people overshoot (NHS vitamin A guidance). A meta-analysis of prospective studies found that higher dietary retinol was associated with a higher risk of hip fracture (RR 1.23 for retinol, 95% CI 1.02 to 1.48), while some carotenoids from plants pointed the other way (Knapik and Hoedebecke, 2021, doi:10.55460/OGLF-K9ZU). A Nordic scoping review reached a similar conclusion on the observational data while noting there is limited new outcomes-based evidence (Olsen and Lerner, 2023, doi:10.29219/fnr.v67.10229). This is observational science, not a verdict, but it is the reason the NHS asks people to keep an eye on the total.
A worked example (hypothetical numbers)
Say your cod liver oil capsule lists 800 µg of vitamin A, your multivitamin lists 800 µg, and you have liver pâté on toast once a week. The two supplements alone come to 1,600 µg, already above the 1,500 µg average the NHS suggests staying under, before any food. Your labels will differ, so use your own numbers. It takes two minutes and removes the guesswork.
Pregnancy, breastfeeding and cod liver oil
This is the point I would put in bold if I could. The NHS advises avoiding liver and liver products in pregnancy because of their very high vitamin A (NHS foods to avoid in pregnancy), and fish liver oil is a concentrated source of the same preformed vitamin A. The usual guidance is therefore to choose an omega-3 with no added vitamin A and to confirm the choice with your midwife or GP. If you are pregnant, breastfeeding or planning a pregnancy, please check before taking any fish oil.
Do you need both? Usually not
Taking cod liver oil and a separate omega-3 is common, usually because someone started one and added the other. It is rarely necessary. The sensible way to check is to add up two things across both labels: the total EPA plus DHA, and the total vitamin A. Aim for EPA plus DHA comfortably above 250 mg a day for the heart role and DHA above 250 mg for the brain and vision roles, and keep vitamin A within the NHS average. If the two products together push your combined EPA and DHA well into the multi-gram range, speak to your GP or pharmacist. Most people who want omega-3 will find one standard fish oil does the job, and if you are choosing between brands, our guide to the best fish oil for heart health covers what to look for.
Reading two labels side by side
- EPA and DHA per serving (not the “fish oil” weight on the front).
- Vitamin A in µg, and whether it is retinol or beta-carotene.
- Vitamin D in µg if listed, so you do not double up with a separate D3.
- Serving size, since one product may need one capsule and another four.
- Form of the oil and allergens: ours contains fish (anchovies).
How to choose by goal
- You want EPA and DHA: a standard omega-3 fish oil is the efficient route, and the one I would pick.
- You want vitamin D: cover it directly with vitamin D3 rather than relying on a fish liver oil.
- You eat no fish at all: an algae omega-3 gives EPA and DHA without fish, which I compare in fish oil vs algae omega-3 and when to take it.
- You love the tradition: that is fine, just do the vitamin A sum first and skip it in pregnancy.
Food first: oily fish, and a note on cod itself
The NHS advice is at least two portions of fish a week, one of them oily, with a portion around 140 g cooked (NHS fish and shellfish). Oily fish such as salmon, mackerel and sardines are the richest food sources of EPA and DHA. Here is the detail that surprises people: cod itself is a white fish, so the flesh is lean. The oil, and the vitamins A and D, are concentrated in the liver, which is exactly why the oil is pressed from it.
Purity, freshness and storage
Any fish oil should be tested for contaminants and kept fresh, because omega-3 oils oxidise over time and a rancid oil is unpleasant. Our omega-3 is tested for purity and heavy metals at our GMP-certified facility. Keep any fish oil cool, dry and out of reach of children, take it with a meal that contains some fat, and be wary of any capsule with a strong stale-fish smell.
What other people say
No fishy burps!
“These are easy enough to swallow and fit nicely with breakfast. High-strength EPA and DHA was another reason I chose them.”
JJames Broadbent · 5-star review on our store (Judge.me)
Good strength without loads of capsules
“I wanted a high EPA and DHA product but didn't want to take a ridiculous number of capsules. These have worked well for me and are easy to include with breakfast. Very happy with them.”
GGeoffrey Linton · 5-star review on our store (Judge.me)
A few cautions worth knowing
Omega-3 is well tolerated by most people. Talk to your GP or pharmacist first if you take blood-thinning medication such as warfarin, are due for surgery, have a liver condition, are pregnant or breastfeeding, or are managing a medical condition. Fish oil is not suitable if you have a fish allergy. Follow the serving on the label, and remember that more is not automatically better, particularly with anything that contains vitamin A.
What to realistically expect
Either oil is a steady everyday addition, not something you feel overnight. The value is in taking a sensible amount regularly alongside a varied diet, which is why I keep coming back to the label numbers rather than the marketing. If you want one simple rule: pick the product that reaches 250 mg of EPA and DHA with the least fuss, check your vitamin A total, and keep it going.
Frequently asked questions
Is cod liver oil the same as omega-3?
No. Cod liver oil is a fish oil pressed from cod livers that contains some omega-3 (EPA and DHA) alongside naturally occurring vitamins A and D. A standard omega-3 fish oil is chosen and concentrated for its EPA and DHA and usually has no added vitamin A.
Can I take cod liver oil and omega-3 together?
You can, but most people do not need both. The practical issue is stacking vitamin A: cod liver oil is a concentrated source, and the NHS advises keeping total vitamin A from food and supplements at or below an average of 1.5 mg (1,500 µg) a day. Add up both labels before you combine them.
Which is better for the heart, cod liver oil or omega-3?
EPA and DHA contribute to the normal function of the heart at 250 mg a day. Both oils can contain EPA and DHA, so the better choice is the one that reaches that amount comfortably without taking you over your vitamin A ceiling, which is usually a standard omega-3 fish oil.
Is cod liver oil safe in pregnancy?
Fish liver oils are a concentrated source of preformed vitamin A, and the NHS advises avoiding liver and liver products in pregnancy for that reason. The usual guidance is to choose an omega-3 without added vitamin A and to check with your midwife or GP first.
Does eating cod give me the same omega-3 as cod liver oil?
Not really. Cod is a white fish, so the flesh is low in oil. The oil, and the vitamins A and D, sit in the liver. For omega-3 from food, oily fish such as salmon, mackerel and sardines are the better choice, with at least one portion (around 140 g cooked) a week.
Our pick for this guide
Ready for a simple daily omega-3?
Omega-3 Fish Oil High Strength EPA & DHA: 1,040 mg EPA and 692 mg DHA in a two-softgel serving. A food supplement, not a replacement for medical advice. Contains fish (anchovies).
From £9.55 · 60 softgels (30 days)
Shop Omega-3 Fish Oil →If you would like to read more, our supplement guides hub brings every guide together, and you can browse the range from the Pure Vitamins UK home page.
Dr. Miron, Founder of Pure Vitamins UK.
Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle. This guide is for general information and is not medical advice. If you are pregnant, breastfeeding, taking medication or managing a medical condition, speak to your GP or pharmacist before starting a new supplement. Contains fish (anchovies).
