Mrm Nutrition Vitamin D3 is a cholecalciferol form of Vitamin D3 extracted exclusively from lichens, an algae/fungi commensal organism, to meet calcium and bone health needs of both vegans and vegetarians. Most dietary Vitamin D3 products come from meat and fish, and most supplemental D3 is typically extracted from sheep s wool (Lanolin) or other animal sources. For this reason, Vitamin D3 supplements have historically not been suitable for either vegetarians or vegans.