Cod Liver Oil: Vitamin A and D Content, Upper Limits and Pregnancy Caution
What vitamin A and D a cod liver oil can contain, the upper limits set by EFSA, Health Canada and the NHS, why pregnancy is a caution, and what trials and cohorts found.
Content last updated . This page has not been medically reviewed.
Urgent and pregnancy points first
Vitamins A and D can be harmful in excessive amounts, and cod liver oil contains both. [1] If a child has swallowed a lot of cod liver oil or any vitamin product, call Poison Help at 1-800-222-1222 in the US (other countries: Poison help by country); call 911 if the person collapses or has trouble breathing.Pregnancy: the NHS (UK) says that unless your GP advises otherwise, avoid fish liver oil supplements when pregnant or trying for a baby, because they are high in vitamin A, which can be harmful to an unborn baby. [2] This is about vitamin A, not omega-3 itself. Pregnancy supplements are covered on Prenatal and postnatal vitamins.
What is in cod liver oil
Fish liver oils such as cod liver oil contain EPA and DHA and also vitamins A and D, in amounts that vary from product to product. [1] The NHS notes fish store vitamin A in their livers. [2] The amounts are on the label; the numbers below are examples, not a standard.- One analysed product (Norwegian trial, 2022). In 5 mL: about 10 µg vitamin D3 (400 IU), 1.2 g long-chain omega-3 (0.4 g EPA and 0.5 g DHA), 250 µg vitamin A and 3 mg vitamin E. [3]
- An older Norwegian formula. Before 1999, cod liver oil in Norway contained 1,000 µg vitamin A per 5 ml. [4] For scale only, that single measure is two-thirds of the NHS's 1,500 µg figure below.
Official upper limits (not targets)
An upper limit (UL) is the highest level of total daily intake from all sources not expected to cause harm in the general population, not an amount to aim for. [5] Units differ by body; we have not converted them. Vitamin A figures are for preformed vitamin A (retinol), not beta-carotene. [5]| Body and year | Group | Vitamin A | Vitamin D |
|---|---|---|---|
| EFSA overview, August 2025 | Adults, including pregnancy and lactation | 3,000 µg RE a day [5] | 100 µg a day [5] |
| EFSA, August 2025 | Children 1 to 3 / 4 to 6 / 7 to 10 years | 800 / 1,100 / 1,500 µg RE [5] | 50 µg each [5] |
| EFSA, August 2025 | Children 11 to 14 / 15 to 17 years | 2,000 / 2,600 µg RE [5] | 100 µg each [5] |
| EFSA, August 2025 | Infants 0 to 6 / 7 to 11 months | 600 / 600 µg RE [5] | 25 / 35 µg [5] |
| Health Canada DRI tables (page dated 2025-11-19) | Adults, pregnancy and lactation | 3,000 µg RAE, preformed vitamin A only [6] | 100 µg (4,000 IU) [6] |
| NHS (UK), vitamin A page (2020) | Adults | No more than an average 1.5 mg (1,500 µg) a day from food and supplements combined [7] | Not applicable |
| NHS (UK), vitamin D page (2020) | Adults and 11 to 17 / 1 to 10 years / infants | Not applicable | 100 µg (4,000 IU) / 50 / 25 µg a day [8] |
The NHS says an average above 1.5 mg a day over many years may affect bones and raise fracture risk, especially for older people and women after menopause, and that fish liver oil counts toward the total. [7] Too much vitamin D can cause calcium to build up in the body (hypercalcaemia). [8] Details are on Vitamin A and Vitamin D.
What research found
| Question | What the source found | Strength |
|---|---|---|
| Does cod liver oil prevent COVID-19 or other respiratory infections? | 34,601 Norwegian adults took 5 mL a day (10 µg vitamin D) or corn oil placebo for up to six months in winter: no reduced risk of infection or serious COVID-19; only low-grade side effects. [3] | No benefit found in this trial |
| Is it linked to asthma? | HUNT cohort, 17,528 Norwegian adults: daily intake for a month or more was linked to new asthma (odds ratio 1.62) with the high-vitamin-A formula. [4] Observational; cannot prove cause. | Observational signal |
| High vitamin A in pregnancy and child asthma | 61,676 children: mothers in the top fifth of total vitamin A intake (2,031 µg RAE or more a day, food and supplements) had a higher child asthma risk (ratio 1.21). [9] | Observational signal |
| Does an emulsified oil raise omega-3 more? | One single-dose crossover in 47 adults: EPA plus DHA blood response 1.66 times higher with one emulsified cod liver oil formulation than a non-emulsified one. [10] | Biomarker only |
Frequently asked questions
Is cod liver oil safe in pregnancy?
The NHS advises avoiding fish liver oil supplements in pregnancy and when trying for a baby unless your GP advises otherwise, because of vitamin A. [2] Ask your midwife, doctor or pharmacist.
How much vitamin A is in cod liver oil?
It varies by product. One analysed Norwegian product had 250 µg per 5 mL. [3] Always check the label. [1]
Is fish oil the same as cod liver oil?
No. Fish oil supplements contain EPA and DHA; fish liver oils also contain vitamins A and D. [1]
Can you take too much vitamin D from cod liver oil?
Yes, in principle, if total vitamin D from all sources is high. The NHS says taking too many vitamin D supplements over a long period can cause hypercalcaemia. [8] Ask a clinician about your total.
Does cod liver oil prevent colds or COVID-19?
A large Norwegian trial found no reduction in infections compared with placebo. [3]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Who should ask a clinician first
Anyone pregnant or planning pregnancy, older adults and women after menopause, children, people taking vitamin A or D products or medicines (see Medication interactions), and anyone with kidney, liver or calcium-related conditions, for which these sources give no specific cod liver oil guidance. Tell your surgical team about all supplements. Do not use cod liver oil to treat a suspected deficiency on your own. For omega-3 comparisons see Fish oil vs cod liver oil and Cod liver oil.
References
- NCCIH, Omega-3 Supplements: What You Need To Know. Read 2026-10-22.
- NHS, Fish and shellfish (page last reviewed 26 June 2026). Read 2026-10-22.
- Brunvoll SH et al. Prevention of covid-19 and other acute respiratory infections with cod liver oil supplementation, a low dose vitamin D supplement: quadruple blinded, randomised placebo controlled trial. BMJ 2022. Read 2026-10-22.
- Mai XM et al. Cod liver oil intake and incidence of asthma in Norwegian adults, the HUNT study. Thorax 2013. Read 2026-10-22.
- EFSA, Overview on Tolerable Upper Intake Levels as derived by the Scientific Committee on Food (SCF) and the EFSA NDA Panel, August 2025. Read 2026-10-22 (text extracted from the PDF).
- Health Canada, Dietary reference intakes tables: Reference values for vitamins (page details dated 2025-11-19). Read 2026-10-22.
- NHS, Vitamin A (page last reviewed 3 August 2020). Read 2026-10-22.
- NHS, Vitamin D (page last reviewed 3 August 2020). Read 2026-10-22.
- Parr CL et al. Vitamin A and D intake in pregnancy, infant supplementation, and asthma development: the Norwegian Mother and Child Cohort. Am J Clin Nutr 2018. Read 2026-10-22.
- Conus N et al. A randomized trial comparing omega-3 fatty acid plasma levels after ingestion of emulsified and non-emulsified cod liver oil formulations. Curr Med Res Opin 2019. Read 2026-10-22.