The Common Cold: What Actually Prevents and Shortens It (and the Long List That Doesn't)

Summary

A short list of things genuinely helps with the common cold and most of the cold/immune-boost market does not, and the dividing line is not "natural versus pharma" but **corrects a specific deficit or blocks transmission** (works) versus **generically boosts a healthy immune system** (doesn't): regular vitamin C modestly shortens duration but does NOT prevent colds and does little when started at onset, zinc lozenges taken early at adequate dose and in the right form genuinely shorten colds though the magnitude is contested, correcting vitamin D **deficiency** (not topping up replete people) c