Seasonal Variation of Provitamin D<sub>2</sub> and Vitamin D<sub>2</sub> in Perennial Ryegrass (<i>Lolium perenne</i> L.)
Ergosterol (provitamin D(2)) is converted to vitamin D(2) in grass by exposure to UV light. Six varieties of perennial ryegrass (Lolium perenne L.) were harvested four times dur...