It's fascinating how much of late-summer through autumn is geared toward biological vitamin D production and storage. High carb and high fat food become readily available through tree mast and cereal harvests, game and livestock are the fattiest they will be all year. High carb, high fat diets make humans store fat. Vitamin D is stored in our fat. I'm totally not surprised that there are mushrooms that can store vitamin D when dried. Because why wouldn't God give us yet another gift.