Vitamin D3 in the Grass Trisetum flavescens

Summary Trisetum favescens , a grass which causes tissue calcification in cattle, was tested for vitamin D-like activity in bioassays using rats and Japanese quail. In both tests, an activity between 3 and 4 I. U. per gram of dry matter was found. An extraction and purification procedure followed by mass spectrometric analysis revealed that a considerable amount of cholecalciferol, the «animal vitamin D», does occur in T. flavescens . Distribution studies showed high concentrations in young, leafy parts and low levels in stems, flowers, seed and roots. Five different breeds of T. flavescens were similar in vitamin Dactivity. T. flavescens grown under complete exclusion of UV-radiation had no vitamin D-activity at all, but an extract of T. flavescens grown without UV-light showed full vitamin D-activity after short exposure to UV-irradiation. These results indicate that the «animal vitamin D» cholecalciferol not only occurs in a higher plant, but is also formed as in the skin of vertebrate animals by UV-radiation from its precursors.