Scientists say they can find no convincing evidence to show that taking vitamin D supplements will fend off a cold. The 161 people who took daily vitamin D for 18 months caught as many colds as the 161 who took fake pills.
The study was reported in the Journal of the American Medical Association.
But a leading UK cold expert said vitamin D was useful. Prof Ronald Eccles, of the Common Cold Center at Cardiff University, said it can give the immune system a much-needed boost during winter when vitamin D reserves may be low.
He said echinacea supplements may also help ward off coughs and colds, but added, “Supplements do not work for everybody because people’s immune systems are different. It’s not a case of one size fits all.”