UV-irradiated mushrooms, enriched in vitamin D2, may improve vitamin D status in individuals with low but not high vitamin D status: new data from an ODIN systematic review and meta-analysis

There is a considerable mismatch between current intakes of vitamin D by many European populations and recommended target intakes for the vitamin [1]. While traditional fortification of milk and other dairy products remains important in tackling inadequate intake, additional strategic approaches to fortification, including biofortification, of a wider range of foods, have the potential to increase vitamin D intakes in the population [2]. Mushrooms are very rich in ergosterol, the principal sterol in fungi, and ultraviolet (UV) radiation from sunlight naturally induces the conversion to ergocalciferol (vitamin D2) in a process resembling the cutaneous synthesis of vitamin D3 in humans. While wild mushrooms can naturally contain high concentrations of vitamin D2, the vitamin D2 content of cultivated mushrooms is very low because they are cultivated indoors without the benefit of UV light [3]. Artificial UV light technology offers potential to enhance the vitamin D2 content of commercial mushrooms and such UV-treated mushrooms are already on the market in Europe.