Sources of vitamin D for humans
What it found
Vitamin D comes from sunlight on the skin, from some foods and from supplements.
Few foods are rich in it, so getting enough from diet alone is hard.
What they found
Sunlight and skin
The body can make vitamin D in the skin when it is exposed to ultraviolet B radiation.
Two main forms
Vitamin D is mainly found in two forms, D3 (cholecalciferol) and D2 (ergocalciferol). A third form, 25-hydroxy vitamin D, also adds significantly to the vitamin D taken in from food.
Rich food sources
Not many foods are a rich source, meaning more than 4 μg/100 g. These include many but not all fish (5-25 μg/100 g), mushrooms (21.1-58.7 μg/100 g), Reindeer lichen (87 μg/100 g) and fish liver oils (250 μg/100 g).
Other food sources
Cheese, beef liver and eggs provide 1.3-2.9 μg/100 g, and dark chocolate provides 4 μg/100 g. Fortified foods include milk, yoghurt, fat spreads, orange juice, breakfast grains and plant-based beverages.
Supplements and intake
The European Food Safety Authority sets an adequate intake of 15 μg/day. Because this is hard to reach through diet alone, vitamin D supplements are usually recommended.
What the authors conclude
“Since an adequate intake of vitamin D (15 μg/day set by the European Food Safety Authority) is hard to achieve through diet alone, dietary supplements of vitamin D are usually recommended.”
Also in their conclusions
- They note that an adequate intake of vitamin D is hard to achieve through diet alone.
- They report that dietary supplements of vitamin D are usually recommended.
How it was done
Vitamin D insufficiency and deficiency are well documented worldwide in relation to human health, which has raised interest in vitamin D research.
What it can’t tell you
- We summarised it from the abstract only.
- This paper pulls together existing knowledge about where vitamin D comes from. It does not test a supplement or food in people, so it cannot show what amount works best for any one person.
Who paid
- Authors work at
- University Medical Centre Ljubljana, Slovenia; University of Ljubljana, Slovenia
The paper
- Title
- Sources of vitamin D for humans
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Summarised from
- Abstract only
- Cite
- Benedik E (2022). Sources of vitamin D for humans. International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition. doi:10.1024/0300-9831/a000733PubMed 34658250DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error