That depends on who you ask. Since the definitions of minerals are wide and varied, many people believe calcium is not a mineral. However, it is generally accepted that calcium is to be treated as a mineral. Calcium is most definitely not a vitamin and t tends to lean towards the minerals as it has many properties of minerals. I’m no chemist but it seems that calcium is not available in nature as an element and therefore might not be a mineral as well. To answer your question, I suppose you can say that calcium is more of a mineral than a vitamin. Hope I dint confuse you even further. :P