I have half an underactive thyroid following removal of the right side for cancer treatment. They also removed a parathyroid gland that was imbedded in the isthmus tissue during and blood tests done in July (5 months post op) have found that I'm Vit D3 deficient and need calcium too. I've finally been prescribed Calceos from my GP but I'm not sure if it is the correct Vit D3. I've read that there is a synthetic version made from sheeps' wool, which I thought was Vit D2, but when I googled colecalciferol (noted on the packaging) it says that this is the synthetic version made from sheeps' wool. Which is correct and is the one I've been prescribed vegan?