Vitamin C and colds

Vitamin C supplements slightly improve physical activity levels and reduce the incidence of colds in men with low vitamin C levels: a randomized controlled trial. The first signs of vitamin C deficiency are mild (fatigue, malaise, depression) and may manifest as a decreased desire for physical activity. In addition, hypovitaminosis C may be associated with colds with increased severity and duration. In this study, researchers estimated the effect of vitamin C on physical activity and respiratory infections during the peak of winter. In the study participated young, healthy, male adults (18-35 years, BMI < 34 kg/m2 and plasma vitamin C < 45 μmol/L) and received either 1000 mg of vitamin C daily or placebo for eight weeks. The results showed that the individuals who received 1000 mg of vitamin C, reported fewer episodes of the common cold and that the duration of colds was reduced by 50%. In addition, the researchers observed a 40% increase in physical activity among participants who received the vitamin C supplement in the last two weeks of the study, compared with the placebo group. The researchers concluded that there are measurable health benefits associated with the intake of vitamin C supplements in a population with normal to low vitamin C levels.

Vitamin C supplementation slightly improves physical activity levels and reduces cold incidence in men with marginal vitamin C status: a randomized controlled trial. Johnston CS, Barkyoumb GM, Schumacher SS. Nutrients. 2014 Jul 9; 6 (7): 2572-83.