Will vitamin D save life? Should I really be taking four times the recommended daily dose?

Very important but not exactly life-saving very important for bone health, calcium You rightly said everyone should take by natural foods sources, also by light sunlight.

Vitamin D is important for the Bones & Joints but it can only be absorbed in small quantities the excess is flushed out. So normally recomended doses is very high to give immediate relief to the patient. for effective absorption it has to be supplkemented with Calcium in your diet or in medicated form.