Possibly, but it probably doesn’t help very much, according to several scientific studies.A 2004 review from Australian National University found that a "routine mega-dose [of vitamin C to prevent disease] is not rationally justified for community use," though the authors noted that vitamin C supplements could help people who have overexerted themselves physically and for individuals who spend significant time in cold environments. The authors revisited their research in 2013, but their conclusions didn't change.Some studies have shown modest benefits for vitamin C supplementation. In 2013, a scientific review found that taking 200 milligrams of vitamin C every day during a cold could help reduce the duration of symptoms in adults by an average of 8 percent—but to get the best possible