What cod liver oil is and why women take it

Cod liver oil is a supplement made from the liver of Atlantic cod fish. It contains omega-3 fatty acids (EPA and DHA), vitamin A, and vitamin D — three compounds that your body cannot make on its own. Women take cod liver oil for different reasons at different life stages: some for bone health as they age, some for skin or joint comfort, some because they are pregnant or breastfeeding and want extra nutrients for their baby.

The oil comes in liquid form, capsules, or gummies. A typical dose is 1,000 to 3,000 mg per day, though amounts vary by brand and by what a woman is taking it for. Because cod liver oil contains fat-soluble vitamins (A and D), taking more than recommended amounts can build up in your body over time, so the dose matters.

Key Takeaways

  • Cod liver oil contains omega-3 fatty acids, vitamin A, and vitamin D, which your body needs but cannot produce.
  • Research shows omega-3s may help reduce joint discomfort and support heart health, though the evidence is stronger for some uses than others.
  • Vitamin D from cod liver oil can support bone strength, which becomes more important for women after menopause.
  • Pregnant and breastfeeding women should talk to their doctor before taking cod liver oil, because vitamin A at high doses can affect fetal development.
  • Cod liver oil can thin blood slightly, so tell your doctor if you take blood thinners or have a bleeding disorder.

Omega-3 fatty acids and joint and heart health

The omega-3 fatty acids in cod liver oil — EPA and DHA — are the main reason many women take it. Your body uses these fats to build cell membranes and to manage inflammation. Research has found that people who eat more omega-3s tend to have lower markers of inflammation in their blood.

For joint health specifically, some studies show that women with joint discomfort who took fish oil supplements reported less pain and stiffness over several months. The effect is modest — not a replacement for medical treatment — but noticeable enough that some rheumatologists mention it as an option. For heart health, omega-3s may help keep blood vessels flexible and support healthy cholesterol levels, though the research is mixed on whether supplements prevent heart disease in people who already eat fish regularly.

The amount of omega-3s matters. A typical cod liver oil capsule contains 300 to 500 mg of combined EPA and DHA. Studies showing benefit often used 1,000 to 3,000 mg per day, so you would need multiple capsules or a larger dose of liquid to reach those amounts.

Vitamin D and bone strength

Cod liver oil is one of the few food sources of vitamin D, and many supplements add extra D on top of what naturally occurs in the oil. Vitamin D helps your body absorb calcium and build bone density. For women, this matters most after menopause, when estrogen levels drop and bones naturally become less dense.

Your body makes vitamin D when skin is exposed to sunlight, but many people — especially those in northern climates or who spend most time indoors — do not get enough from sun exposure alone. Cod liver oil can help close that gap. A typical serving provides 400 to 1,000 IU of vitamin D, depending on the brand. The recommended daily amount for women over 50 is 600 to 800 IU from all sources combined, though some research suggests higher amounts may be beneficial.

If you take a separate vitamin D supplement, check the label on your cod liver oil to avoid taking too much D overall. Excess vitamin D can build up in your body and cause problems.

Vitamin A and skin health

Cod liver oil contains preformed vitamin A (retinol), which your body can use directly. Vitamin A supports skin cell turnover and may help reduce the appearance of fine lines and uneven tone. Some women take cod liver oil partly for this reason, though the amount of vitamin A in a typical dose is modest.

Vitamin A is fat-soluble, meaning it accumulates in your body's fatty tissues over time. Taking too much — especially over months or years — can cause vitamin A toxicity, which can weaken bones and cause other problems. This is why the dose matters and why pregnant women need to be especially careful: high vitamin A in early pregnancy has been linked to birth defects.

If you are already using a retinol or retinoid skin product (like prescription tretinoin or over-the-counter retinol), adding cod liver oil increases your total vitamin A intake. Talk to your doctor or dermatologist before combining them.

Pregnancy, breastfeeding, and special considerations

Pregnant and breastfeeding women often wonder whether cod liver oil is safe. The omega-3s are beneficial — some research suggests they support fetal brain development — but the vitamin A is the concern. High doses of preformed vitamin A in the first trimester have been associated with birth defects. For this reason, many doctors recommend that pregnant women avoid standard cod liver oil and instead take a prenatal supplement formulated for pregnancy, which contains a safer form of vitamin A or a lower amount.

If you are breastfeeding, small amounts of vitamin A from cod liver oil pass into breast milk, but typical doses are considered safe. Still, check with your doctor or midwife before starting any new supplement while breastfeeding.

Cod liver oil can also thin blood slightly. If you take blood thinners (like warfarin or aspirin), have a bleeding disorder, or are scheduled for surgery, tell your doctor that you take cod liver oil. You may need to stop it before a procedure or adjust other medications.

How to choose and use cod liver oil

Cod liver oil comes in several forms: liquid (often flavored to mask the fishy taste), capsules, and gummies. Liquid allows you to adjust the dose more easily, while capsules are convenient and odorless. Gummies are popular but often contain less omega-3 per serving than capsules or liquid, so check the label.

Look for products that have been tested by a third party — organizations like NSF International or USP verify that the product contains what the label says and is free of contaminants like mercury. Cod liver oil can go rancid if stored in heat or light, so keep it in a cool, dark place or in the refrigerator if it is liquid.

Start with the dose recommended on the label. If you are taking it for a specific reason — joint comfort, bone health, or heart health — give it at least two to three months before deciding whether it is working for you. Some effects take time to notice.

Possible side effects and interactions

Cod liver oil is generally well tolerated, but some women experience mild side effects. The most common is a fishy aftertaste or burps that smell like fish, especially with liquid or capsules. Taking it with food can reduce this. Some people report mild nausea, loose stools, or stomach upset, particularly at higher doses.

Because cod liver oil can thin blood slightly, combining it with blood thinners, NSAIDs taken regularly, or other supplements that affect clotting (like ginkgo or garlic supplements) may increase bleeding risk. If you take any of these, mention your cod liver oil to your doctor.

Cod liver oil may also interact with certain medications, including some blood pressure drugs and diabetes medications. If you take prescription medications, ask your pharmacist or doctor whether cod liver oil is safe to combine with them.

Frequently Asked Questions

Is cod liver oil better than regular fish oil for women?

Cod liver oil and fish oil both contain omega-3s, but cod liver oil also includes vitamins A and D. If you want those vitamins, cod liver oil makes sense. If you only want omega-3s and want to avoid extra vitamin A, regular fish oil may be a better choice. The omega-3 content is similar in both.

Can I take cod liver oil if I eat fish regularly?

Yes, but check your total vitamin A and D intake. If you eat fatty fish (like salmon or mackerel) several times a week, you are already getting omega-3s and some vitamin D. Adding cod liver oil increases your intake of all three compounds, which is fine at normal doses but worth being aware of.

How long does it take to notice a difference?

For joint comfort or heart health, most research studies ran for two to three months before measuring results. Skin changes may take longer — several months of consistent use. Bone health benefits also build over time and are harder to notice without a bone density scan.

Is liquid or capsule form better?

Both work equally well. Liquid allows easier dose adjustment and may be absorbed slightly faster, but capsules are more convenient and have no aftertaste. Choose based on what you will actually take consistently.

What should I do if I want to take cod liver oil but I am pregnant?

Talk to your doctor or midwife before starting. They may recommend a prenatal supplement instead, which is formulated to be safe in pregnancy. Some doctors do allow low-dose cod liver oil, but the decision depends on your individual situation.