86% of zinc-treated subjects became cold-free after 7 days compared with only
46% of placebo-treated subjects. Eby GA et al: Reduction in duration of
common colds by zinc gluconate lozenges in a double-blind study. Antimicrobic
agents and chemotherapy 25(1):20-24, 1984
100 volunteers who had developed a cold within the last 24 hours were
randomized to receive either zinc gluconate lozenges or placebo for as long as
their symptoms lasted. Those in the zinc group had significantly shorter colds
(average 4.4 days) than the control group (7.6 days). They also had
significantly fewer days with coughing, hoarseness, nasal congestion, nasal
drainage and sore throat. Mossad SB et al: Zinc gluconate lozenges for treating
the common cold. A randomized, double-bind, placebo-controlled study. Ann Intern
Med 125(2):81-8, 1996.
Treatment of colds with zinc reduced the mean daily clinical score and the
mean daily nasal secretion. Al-Nakib W et al: prophylaxis and treatment of
rhinovirus colds with zinc gluconate lozenges. J Antimicrob Chemother 20(6):893-901, 1987
140 pre-school age children with a history of frequent respiratory illnesses
were supplemented with vitamin A (450 ug per day) or a placebo. The children
given the vitamin A suffered 19% fewer episodes than the placebo group. Pinnock
CB et al: Vitamin A status in children who are prone to respiratory tract
infections. Aust Paediatr J 22(2):95-9, 1986.
There are a large number of placebo-controlled double-blind studies which
consistently and persuasively support the conclusion that vitamin C
supplementation alleviates the symptoms of the common cold. Hamila H et al:
Vitamin C and the common cold: A retrospective analysis of Chalmers' review. J
Amer Coll Nutr 14(2):116-123, 1995.
