I asked my oncologists and urologists the same question, and they all gave me the same scripted answer. No one knew if vitamins could help my cancer. No one knew if I could affect my IGF1 levels by diet ("I don't know but I doubt that.").
After this, I worked closely with several surgeons and realized how non-curious most doctors/surgeons are.
We create systems and then train individuals to operate within those systemically flawed organizations. The medical industry is incredibly complicated due to each link in the chain collecting their often exorbitant fees.