Vitamin C does, in fact, decrease both the duration and severity of colds. And studies conducted after Pauling's and Chalmers' meta-analyses have born this out. Medical attitudes against vitamins were strident in the 1970s, despite a considerable volume of evidence indicating their effectiveness. In the 1990s, the anti-vitamin rhetoric is still alive, but it is being toned down to a large degree by the volume of young professionals entering science and medicine who know beyond a shadow of a doubt that their older peers are just plain wrong. The ostracism of Pauling is a testament to the corrupting influence of politics in medicine and science.
Scientists have their peer-review standards for publishing and government grants.
But political corruption of science and medicine is also due to the fact that scientists and doctors are people, and people are social and political animals. As a methodology, science can make claims to impartiality, detachment and lack of bias. But as an institution, it can never be so. Scientists, and doctors, are people like everybody else. And just as religious institutions have been corrupted to the interests of wars and genocide, scientists are corrupted by politics, pride and avarice to suppress good science.