Vit D for sure. Vit. C is supposed to help deter spread. I take a timed release 1000 each day. Also have you other levels cheched, you may need magnesium and get get some thru skin with Epsom salt soaks which I also do daily. I am a sun gal and when I got RSD my Vit. D was 6!!!!! I too must take it every day to maintain a normal. Carol