Never mind the vitamin C, new research carried out at the University of Alberta in Canada, and the University of Auckland, New Zealand, suggests that the best way to avoid the common cold is to wash your hands.
(If you insist on paying for supplements, a daily dose of 10 or 15 milligrams of zinc sulphate has been shown to lower rates of colds. Probiotics, which boost the amount of friendly bacteria in the gut, may help prevent colds too, and our old friend honey had a slight effect in relieving cough symptoms, but vitamin C and antibiotics showed “no benefit”.
I notice they said nothing about the medicinal effects of a hot toddy.)