Cod Liver Oil vs. Krill Oil: Which Omega-3 Supplement Is Better?

January 5, 2026 •

3 min read

Historically used for centuries to combat rickets, cod liver oil has long been a staple supplement, but modern alternatives like krill oil present a compelling comparison. When considering what's better, cod liver oil or krill oil, the answer depends on your specific nutritional goals, budget, and preference for nutrient profiles.

Quick Summary

This article compares cod liver oil and krill oil based on their unique compositions, bioavailability, and additional nutrients like vitamins A, D, and the antioxidant astaxanthin. We explore which supplement aligns best with different health objectives, from heart and brain health to immune and bone support, while considering cost and consumer experience.

Key Points

Absorption: Krill oil’s omega-3s are bound to phospholipids, potentially offering better bioavailability and absorption than the triglyceride form in cod liver oil.
Vitamins: Cod liver oil is rich in vitamins A and D, providing significant benefits for bone health, immunity, and vision, but requires cautious dosing to prevent vitamin toxicity.
Antioxidants: Krill oil contains astaxanthin, a potent antioxidant that protects the oil from oxidation and provides additional anti-inflammatory and cellular protection.
Taste: Krill oil has a milder taste and is less prone to causing fishy burps compared to cod liver oil, making it a more palatable option for many users.
Cost: Cod liver oil is generally more affordable than krill oil, but the higher cost of krill oil may be offset by potentially needing a lower dose for comparable omega-3 benefits.
Allergies: Individuals with shellfish allergies should avoid krill oil and opt for cod liver oil or an algal alternative.
Purpose: Choose cod liver oil if you need extra vitamins A and D, or krill oil if your focus is on superior omega-3 absorption and antioxidant support.

Nutritional Profiles at a Glance

Cod Liver Oil

Extracted from the liver of codfish, this oil is a traditional powerhouse, known for its combination of omega-3s and high levels of fat-soluble vitamins.

Omega-3s: Contains EPA and DHA, but often in lower concentrations per serving compared to many modern fish oils.
Vitamins: Exceptionally rich in vitamins A and D, with a single teaspoon often exceeding daily recommended intakes.
Other Nutrients: Minimal amounts of other trace nutrients.

Krill Oil

Sourced from tiny, shrimp-like Antarctic crustaceans, krill oil has a distinct composition that affects its absorption and benefits.

Omega-3s: Contains EPA and DHA bound to phospholipids, which is thought to improve bioavailability and absorption.
Antioxidants: Naturally contains astaxanthin, a powerful antioxidant that gives the oil its red color.
Other Nutrients: Contains choline, which supports brain function.

Bioavailability and Absorption: A Key Differentiator

Omega-3s in krill oil are bound to phospholipids, which are integral to cell membranes, potentially leading to more efficient absorption compared to the triglyceride form of omega-3s in cod liver oil. While some studies suggest higher blood levels of omega-3s with krill oil, the overall findings can vary. Cod liver oil's triglyceride form is still highly bioavailable but follows a standard absorption route.

Vitamins A and D: Cod Liver Oil's Advantage

Cod liver oil is a significant source of vitamins A and D, supporting immunity, bone health, and vision. High vitamin A content requires careful dosing to avoid toxicity, especially if other vitamin supplements are taken. Krill oil offers a purer omega-3 and antioxidant source with lower vitamin levels.

Astaxanthin and Choline: Krill Oil's Unique Edge

Krill oil contains astaxanthin, a potent antioxidant that gives it a red color and offers anti-inflammatory benefits. Astaxanthin contributes to the oil's stability and may support heart, eye, and skin health. Krill oil also provides choline, important for liver and brain function.

Comparison Table: Cod Liver Oil vs. Krill Oil


Feature	Cod Liver Oil	Krill Oil
Omega-3 Form	Triglyceride	Phospholipid
Absorption Rate	Standard	May be more bioavailable
Additional Nutrients	High in Vitamins A & D	Astaxanthin & Choline
Antioxidant Content	Moderate (Vitamins A & D)	High (Astaxanthin)
Best For	Bone health, immune support, vision	Heart, brain, anti-inflammatory support
Price	Generally more affordable	Often more expensive
Taste/Aftertaste	Stronger, can cause fish burps	Milder, less fishy aftertaste
Sustainability	Varies by brand and practice	Often from sustainable sources (e.g., MSC certified)
Allergy Risk	Low (fish-based)	High (shellfish allergy)

Cost and Consumer Experience

Krill oil is generally more expensive than cod liver oil due to its specialized processing. However, many prefer krill oil for its milder taste and reduced fishy aftertaste. Both are available in various forms, including capsules, which can help mask the taste.

Who Should Choose Which?

Choose based on your health goals and any limitations.

Choose Cod Liver Oil if... you need vitamins A and D for bone and immune health and prefer a more affordable option, being mindful of vitamin A dosage.
Choose Krill Oil if... you prioritize enhanced omega-3 absorption, antioxidant benefits from astaxanthin, and a milder taste. It may be better for cardiovascular support.

Conclusion: Making the Best Choice for Your Needs

The choice between cod liver oil and krill oil is personal, based on individual health needs and goals. Cod liver oil provides vitamins A and D for bone and immune health, while krill oil offers superior omega-3 absorption and astaxanthin benefits for inflammatory and cardiovascular issues. Consider cost, allergies, and vitamin needs, and consult a healthcare provider before starting any new supplement.

Authoritative Outbound Link

For more information on the health benefits of omega-3 fatty acids, consult the National Institutes of Health's Office of Dietary Supplements: Omega-3 Fatty Acids Fact Sheet for Health Professionals

Frequently Asked Questions

While it is possible to combine these supplements, it is best to consult a healthcare provider first. Taking both can significantly increase your omega-3 intake and raise concerns about excess vitamin A and D from the cod liver oil. A doctor can help determine a balanced approach.

Both contain anti-inflammatory omega-3s that may ease joint pain. Some smaller studies suggest krill oil's higher absorption rate and antioxidant content may provide faster relief, but more research is needed. Cod liver oil's high vitamin D content is also essential for bone health, which contributes to overall joint support.

Both oils support heart health by providing omega-3s that can lower triglycerides and reduce inflammation. Krill oil's potential for superior absorption and astaxanthin content may give it an edge for improving cholesterol profiles, but both offer significant cardiovascular benefits.

Krill oil is generally associated with fewer and milder fishy burps or aftertaste than traditional cod liver oil. Its phospholipid-bound omega-3s emulsify better with stomach fluids, reducing the unpleasant taste and odor.

Due to the high levels of vitamin A in cod liver oil, pregnant women should consult their doctor before use. Excess vitamin A can be harmful to the developing fetus, making krill oil a potentially safer omega-3 option during pregnancy, though it's still best to seek medical advice.

Both oils rely on responsible harvesting, but krill populations are generally considered more resilient due to their rapid reproduction rate. Consumers can look for products with sustainability certifications, such as the Marine Stewardship Council (MSC), for krill oil.

Krill oil contains minimal amounts of vitamins A and D, not enough to provide the same benefits as cod liver oil. If boosting your intake of these specific vitamins is a goal, cod liver oil is the more effective choice.

Krill oil is typically more expensive than cod liver oil. The higher cost is attributed to the specialized harvesting and processing methods required for krill.

Astaxanthin is a powerful antioxidant found naturally in krill oil, responsible for its red color. It has anti-inflammatory properties and helps protect cells from damage caused by oxidative stress.