With the new scientific breakthrough in capturing Vitamin D2 from mushrooms. Our D2 is sourced from Agaricus bisporus mushrooms. This mushroom species is the well-known button/ baby bella/portabella, all the same species harvested at different growth stages. Mushrooms have a natural level of Vitamin D. When exposed to sunlight, they synthesize Vitamin D. This increased Vitamin D does not involve any additives, supplements, or chemicals. Our Hi D is completely natural and not synthetic.