Vitamin C prophylaxis in marine recruits

Area of Science:

• Clinical Nutrition
• Respiratory Medicine
• Preventive Medicine

Background:

• The common cold is a widespread respiratory illness with significant public health impact.
• Prophylactic use of vitamin C (ascorbic acid) is often considered for preventing respiratory infections.

Purpose of the Study:

• To investigate the efficacy of vitamin C prophylaxis in reducing the incidence and morbidity of the common cold and other respiratory illnesses.
• To evaluate the impact of high-dose vitamin C supplementation on cold severity and related outcomes.

Main Methods:

• A prospective, randomized, double-blind, placebo-controlled study.
• Involved 674 marine recruits over an eight-week period.
• Assessed whole-blood ascorbic acid levels, cold incidence, duration, severity, and sick-call visits.

Main Results:

• Significantly higher whole-blood ascorbic acid levels were observed in the vitamin C group.
• No significant difference was found in the incidence or duration of common colds between vitamin C and placebo groups.
• The vitamin C group reported subjectively less severe colds, but this did not correlate with symptom complexes or reduced sick-call visits.

Conclusions:

• Prophylactic high-dose vitamin C supplementation does not appear to prevent the common cold or reduce its duration.
• Subjective reporting of cold severity may be influenced by vitamin C, but objective measures like sick-call visits are not affected.
• Current evidence does not support the routine prophylactic use of vitamin C for preventing common colds.