Cod Liver Oil and Fatty Fish: What Food Holds the Most Vitamin D?

October 24, 2025 •

3 min read

According to the National Institutes of Health, a single tablespoon of cod liver oil contains a staggering 1,360 IU of vitamin D, making it the most concentrated dietary source available. While cod liver oil leads the way, many other foods, both natural and fortified, can help you meet your daily needs for this essential nutrient.

Quick Summary

Cod liver oil offers the highest concentration of vitamin D, followed by fatty fish such as trout and salmon. Fortified foods like milk, orange juice, and cereals, along with UV-exposed mushrooms, also provide significant amounts to support bone health and other bodily functions.

Key Points

Cod Liver Oil is the most potent source: One tablespoon of cod liver oil contains a very high concentration of vitamin D, offering 1,360 IU.
Fatty fish are excellent natural sources: Wild-caught salmon, trout, herring, and sardines are rich in vitamin D, with content varying by species.
Mushrooms can be a good vegetarian option: Mushrooms exposed to UV light are a significant source of vitamin D, though most store-bought varieties are grown in the dark.
Fortified foods help bridge the gap: Many common foods like milk, orange juice, and cereals are fortified with vitamin D to aid public intake.
Differentiate between D2 and D3: Vitamin D3 (from animals) is generally considered more effective at raising blood levels than vitamin D2 (from plants), although both are absorbed well.
Maximize absorption with fat: Since vitamin D is fat-soluble, consuming it with some dietary fat can improve its absorption by the body.
Consider supplementation: Especially during seasons with low sun exposure, supplements might be necessary to meet daily vitamin D requirements.

Top Contenders for the Most Vitamin D

While sunlight is a primary source of vitamin D, dietary intake is crucial, especially during months with limited sun exposure. Knowing what food holds the most vitamin D can help you make informed choices to support bone health, immune function, and overall wellness. While cod liver oil is the clear winner in terms of sheer concentration, a variety of other natural and fortified foods offer excellent options.

The Reigning Champion: Cod Liver Oil

Cod liver oil is a potent source of vitamin D, with a single tablespoon providing 1,360 IU (34.0 mcg). This significantly exceeds the daily value for most adults and makes it a highly efficient way to increase your intake.

Stellar Natural Sources: Fatty Fish

Fatty fish are among the best natural sources of vitamin D. The amount can vary depending on whether the fish is wild-caught or farmed, with wild-caught often having higher levels.

Rainbow Trout: A 3-ounce serving of cooked farmed rainbow trout contains 645 IU of vitamin D.
Salmon: Sockeye salmon is another excellent source, providing 570 IU in a 3-ounce cooked portion. Wild-caught salmon can offer even more.
Herring and Sardines: These smaller fatty fish also contribute significantly to vitamin D intake.

The Vegetarian and Vegan Exception: UV-Exposed Mushrooms

Mushrooms that have been exposed to ultraviolet (UV) light can produce vitamin D, making them a valuable option for vegetarians and vegans.

UV-Treated Mushrooms: Some commercially grown mushrooms are treated with UV light to boost their vitamin D content. A half-cup of sliced, UV-exposed white mushrooms provides 366 IU.
Wild Mushrooms: Certain wild varieties also contain vitamin D due to natural sun exposure.

Fortified Foods: A Daily Boost

Since few foods naturally contain high levels of vitamin D, many common items are fortified to help people meet their needs.

Fortified Milk: A cup of fortified milk, including dairy and plant-based options, typically offers around 120 IU.
Fortified Orange Juice: Some orange juice brands provide about 100 IU per cup.
Fortified Cereals: Many breakfast cereals are fortified, adding about 80 IU per serving.
Other Fortified Products: Certain yogurts and tofu products also have added vitamin D.

Comparison of Vitamin D Sources

This table presents a comparison of some key food sources of vitamin D, referencing data from the National Institutes of Health.


Food Source	Serving Size	Vitamin D (IU)	Vitamin D (mcg)	Natural or Fortified
Cod Liver Oil	1 tablespoon	1,360	34.0	Natural/Supplement
Rainbow Trout	3 oz cooked	645	16.2	Natural
Sockeye Salmon	3 oz cooked	570	14.2	Natural
UV-Exposed Mushrooms	1/2 cup raw	366	9.2	Natural (UV-treated)
Fortified 2% Milk	1 cup	120	2.9	Fortified
Fortified Orange Juice	1 cup	100	~2.5	Fortified
Fortified Cereal	1 serving	80	2.0	Fortified
Canned Sardines	2 sardines	46	1.2	Natural
Egg (yolk)	1 large scrambled	44	1.1	Natural
Beef Liver	3 oz braised	42	1.0	Natural

Optimizing Your Vitamin D Intake

Maintaining sufficient vitamin D levels often involves a combination of diet, sunlight, and sometimes supplements. Given the limited natural sources, fortified foods are important for many people.

Considerations:

Dietary Choices: Omnivores can include fatty fish and eggs, while vegetarians and vegans can focus on UV-exposed mushrooms and fortified plant-based options.
Environmental Factors: Sun exposure varies by location and season, impacting vitamin D production.
Skin Tone: Darker skin reduces the ability to produce vitamin D from sunlight.
Fat Intake: Consuming vitamin D with dietary fat can aid absorption.

Conclusion

Dietary intake is vital for adequate vitamin D, complementing sunlight exposure. Cod liver oil is the most concentrated food source, but fatty fish, UV-exposed mushrooms, and fortified items like milk and cereals also contribute significantly to meeting daily requirements. A varied approach is key to managing your intake of this essential nutrient.

This information is for educational purposes only and is not a substitute for professional medical advice. Always consult a healthcare provider before starting a new supplement regimen.

Additional Resources

National Institutes of Health, Office of Dietary Supplements: Vitamin D Fact Sheet for Health Professionals

Frequently Asked Questions

Cod liver oil has the highest natural concentration of vitamin D per serving. A single tablespoon contains 1,360 IU, far exceeding other food sources.

Yes, but only if they have been exposed to ultraviolet (UV) light. Wild mushrooms or commercially treated mushrooms can provide significant amounts of vitamin D2, which helps raise blood levels.

The best non-animal food sources of vitamin D are UV-exposed mushrooms and fortified foods like plant-based milks, tofu, and cereals.

Fortified foods can contribute significantly to your daily vitamin D intake, but they alone may not be enough to meet the full daily requirements, especially for those with low sun exposure. Combining them with other sources or supplements might be necessary.

Yes, studies have shown that wild-caught salmon generally contains higher levels of vitamin D than farmed salmon.

Vitamin D2 (ergocalciferol) comes from plants and fungi, while vitamin D3 (cholecalciferol) comes from animals. Most evidence suggests that D3 is more effective at raising and maintaining blood levels of the vitamin.

It is highly unlikely to get too much vitamin D from food alone. Vitamin D toxicity typically occurs from over-supplementation, not from dietary intake or sun exposure.