Sources of vitamin D for humans.
Level 5 - mechanism / opinion, no new human data
Narrative review summarizing dietary and cutaneous sources of vitamin D without systematic search methodology.
PubMed 34658250 · doi:10.1024/0300-9831/a000733
What was done
The authors conducted a literature review detailing the sources of vitamin D available to humans, encompassing endogenous cutaneous synthesis via ultraviolet B radiation, dietary supplements, fortified foods, and natural plant- and animal-derived foods.
What was found
Vitamin D occurs primarily as D3 (cholecalciferol), D2 (ergocalciferol), and 25-hydroxyvitamin D. Natural rich sources (>4 μg/100 g) are limited to select 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). Modest sources include cheese, beef liver, and eggs (1.3–2.9 μg/100 g), as well as dark chocolate (4 μg/100 g). Because standard diets rarely meet the European Food Safety Authority adequate intake target of 15 μg/day, fortification and supplementation are routinely recommended.
Why it matters
This review compiles specific food concentrations and intake pathways, illustrating the structural difficulty of meeting physiological vitamin D requirements through unfortified dietary intake alone.
Limits
The abstract describes a narrative review rather than a systematic review or meta-analysis, providing no systematic search criteria, quality appraisal of cited analytical studies, or quantitative intake data across specific human populations.
Cited by
- supports Lichen species synthesize vitamin D3 and can be utilized as a vegan source of vitamin D3.