Sources of vitamin D for people in food and sunlight
What it found
Vitamin D comes from sunlight on skin, certain foods, fortified products and supplements.
Few foods naturally contain more than 4 μg per 100 g.
What they found
How vitamin D is made
The body makes vitamin D when ultraviolet B light hits the skin. People can also take it in through food or supplements.
Two main forms
Vitamin D mainly appears as D3 and D2. A third form called 25-hydroxy vitamin D also adds meaningfully to what people take in from food.
Rich natural sources
Few foods have more than 4 μg per 100 g. Fish liver oils have 250 μg per 100 g, reindeer lichen 87 μg, mushrooms 21.1 to 58.7 μg and many fish 5 to 25 μg per 100 g.
Other food sources
Cheese, beef liver and eggs provide 1.3 to 2.9 μg per 100 g. Dark chocolate has 4 μg per 100 g. Fortified milk, yoghurt, spreads, juice, cereals and plant drinks also add vitamin D.
Daily intake target
The European Food Safety Authority sets an adequate intake at 15 μg per day. The authors say this is hard to reach through diet alone, so supplements are usually recommended.
What the authors conclude
- They note that getting enough vitamin D from food alone is difficult because few items are rich sources.
- They point out that dietary supplements are usually recommended to meet the daily target of 15 μg.
How it was done
Low vitamin D levels are well documented around the world and linked to human health. This raised interest in where people can get it.
The authors reviewed published research on where vitamin D comes from for humans. They looked at sunlight, natural foods, fortified foods and supplements.
What it can’t tell you
- We summarised it from the abstract only.
- This work gathered existing information rather than testing vitamin D directly in people or animals.
- It cannot show whether one source works better than another inside the body.
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 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error