evidence: Choosing the right form of vitamin D for you will depend primarily on your diet. Unlike vitamin D2 (ergocalciferol) which can only be found in plant-based sources, vitamin D3 (cholecalciferol) can be synthesized within the body or via consuming animal products and meats. When ultraviolet (UVB) radiation from sunlight contacts your skin cells, it creates vitamin D3. Then, the stored inactive version of the vitamin (AKA 25-hydroxyvitamin d) is converted by the kidneys into its active form of calcitriol. The total body effects of vitamin D are too good to pass up! [...] Diet alone typically cannot provide the amount of vitamin D that your body needs. By taking a multivitamin and/or vitamin D supplement, you can fill in the gaps. Most vitamin D3 supplements are not vegan, as they are sourced from lanolin, the coating of sheep's wool. With that said, vegan Vitamin D3 supplements are out there. Also known as lichen vitamin D3, these supplements derive vitamin D from algae and lichen fungus. Find out why vitamin D3 and K2 should be combined with omega-3 fatty acids.