Pure Encapsulations vitamin D3 (vegan) is derived from organic algae. It is produced through a multistep process involving extraction, purification and concentration resulting in a vitamin D3 cholecalciferol with the same molecular structure and conformation as lanolin and fish oil-derived cholecalciferol. Research indicates that optimal vitamin D serum levels offer support for bone, breast, prostate, cardiovascular, colon and immune health.