Initial Vitamin D2 content in all groups was circa 0.5 µg/100g. Each sample was 30 g and after a single UVB pulse reached from ca. 20 to ca.150 µg/100g, proportionally to applied pulse energy, which respectively varied from 100 to 1000 J/pulse. Champignons had about 25% higher D2 response at the same pulse energies as oysters had. The precision D2 enrichment was demonstrated in these tests and allows to meet RDA standards for D2 (5 to 10µg/100 g, depending on a population group) on an industrial level, without side-effects such as mushroom browning or dehydration.