Vitamin D in Diet - Good Natural Sources

Vitamin D is an essential nutrient that the body primarily produces through sunlight exposure on the skin. However, only a few foods naturally contain significant amounts of vitamin D. The best natural sources include fatty fish such as trout, salmon, and mackerel. The vitamin D content in animal product is also influenced by the animal's diet. Smaller amounts of vitamin D can be found in foods like beef liver, egg yolk and cheese, mainly in the form of vitamin D3 and its metabolite 25(OH)D3. Mushrooms contain varying amounts of vitamin D2, with the UV-treated mushrooms showing higher concentrations. In the United States, the Food and Drug Administration (FDA) has even approved UV-treated mushroom powder as a source of vitamin D2 in foods. 

Overall, diet contributes only about 20% to meet daily vitamin D requirements. Plant-based foods play a minor role in this, as they typically contain very little vitamin D2. In many countries, such as the United States, fortified foods play a significant role in the population's vitamin D supply. Almost the entire milk production in the U.S. is artificially fortified with about 3 µg of vitamin D per cup (120 IU). Similarly, plant-based milk alternatives like soy, almond, or oat milk often contain similiar amounts of added vitamin D. In Canada, milk and margarine must be fortified with vitamin D, while in Germany, only certain products like margarine or mixed fats may be fortified with Vitamin D. Additionally, UV-treated milk are approved as novel foods in the EU. Products designed for low-calorie diets for weight loss must also contain a specific amount of vitamin D. 

Interestingly, animal foods contain not only vitamin D3 but also 25(OH)D, a form of vitamin D that is particularly effective in the body. Studies show that 25(OH)D is about five times more effective than vitamin D3 in increasing blood vitamin D levels. Therefore, the vitamin D content in meat, poultry, and eggs can be significantly higher than what would be expected based solely on the pure vitamin D3 content.

The exact amount of vitamin D contained in foods is shown by the German Nutrition Society (Deutsche Gesellschaft für Ernährung e.V.): 

This table shows the vitamin D content of selected foods in micrograms per 100 grams. It highlights that only a few foods naturally contain significant amounts of vitamin D. Especially fatty fish like herring, salmon, and mackerel are excellent sources of vitamin D. Herring contains the highest values, with up to 25 micrograms per 100 grams, followed by salmon with 16 micrograms. Egg yolk is also a good source, with 5.6 micrograms per 100 grams.

Animal products such as beef and calf liver also contain small amounts of vitamin D, but in much lower concentrations compared to fish. Margarine, which is partially fortified, can also reach high values of up to 7.5 micrograms, while other animal fats like butter contain less vitamin D. Mushrooms like chanterelles and regular mushrooms contribute to plant-based vitamin D intake, with chanterelles showing slightly higher values at 2.1 micrograms compared to 1.9 micrograms for regular mushrooms. Whole milk has a very low vitamin D content of 0.09 micrograms, which explains the need for fortified foods. Overall, the table indicates that fatty fish are the most important natural sources of vitamin D, while plant-based foods and dairy products contain significantly lower amounts of this nutrient. As natural vitamin D intake through food is often insufficient, the fortification of food is becoming increasingly important. 

Sources: 

Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit. (2022). Ausführliche Informationen zu Vitamin D. Source

Deutsche Gesellschaft für Ernährung e.V. (2024). Vitamin D (engl.). DGE. Source

National Institute of Health. (2024). Office of Dietary Supplements—Vitamin D. Vitamin D Fact Sheet for Health Professionals. Source