Anyone have a low CBC 2 weeks before PS?

I had my bloodwork done on Monday for my PS on August 10.  Dr. office just called back and said my 'CBC was low' and that I needed to take a mutli vitamin and vitamin C.  I haven't been good with taking my vitamins every single day, but I do take them.  I do not take an extra Vitamin C though.  Does anyone know what this means?  My surgery is still on, thank God!