Vitamin C Supplementation Slightly Improves Physical Activity Levels and Reduces Cold Incidence in Men With Marginal Vitamin C Status: A Randomized Controlled Trial

Nutrients. 2014 Jul 9;6(7):2572-83. doi: 10.3390/nu6072572.

Abstract

The early indications of vitamin C deficiency are unremarkable (fatigue, malaise, depression) and may manifest as a reduced desire to be physically active; moreover, hypovitaminosis C may be associated with increased cold duration and severity. This study examined the impact of vitamin C on physical activity and respiratory tract infections during the peak of the cold season. Healthy non-smoking adult men (18-35 years; BMI < 34 kg/m2; plasma vitamin C < 45 µmol/L) received either 1000 mg of vitamin C daily (n = 15) or placebo (n = 13) in a randomized, double-blind, eight-week trial. All participants completed the Wisconsin Upper Respiratory Symptom Survey-21 daily and the Godin Leisure-Time Exercise Questionnaire weekly. In the final two weeks of the trial, the physical activity score rose modestly for the vitamin C group vs. placebo after adjusting for baseline values: +39.6% (95% CI [-4.5,83.7]; p = 0.10). The number of participants reporting cold episodes was 7 and 11 for the vitamin C and placebo groups respectively during the eight-week trial (RR = 0.55; 95% CI [0.33,0.94]; p = 0.04) and cold duration was reduced 59% in the vitamin C versus placebo groups (-3.2 days; 95% CI [-7.0,0.6]; p = 0.06). These data suggest measurable health advantages associated with vitamin C supplementation in a population with adequate-to-low vitamin C status.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Ascorbic Acid / administration & dosage*
  • Ascorbic Acid / blood
  • Ascorbic Acid Deficiency / blood
  • Ascorbic Acid Deficiency / drug therapy
  • Body Mass Index
  • Common Cold / blood
  • Common Cold / prevention & control*
  • Dietary Supplements*
  • Double-Blind Method
  • Health Surveys
  • Healthy Volunteers
  • Humans
  • Incidence
  • Male
  • Motor Activity / drug effects*
  • Nutritional Status
  • Surveys and Questionnaires
  • Wisconsin
  • Young Adult

Substances

  • Ascorbic Acid