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Vitamin C and acute illness in Navajo schoolchildren
Insights
Vitamin C supplementation did not reduce the incidence or duration of common colds in children. Higher vitamin C levels were paradoxically linked to longer illness duration, suggesting no therapeutic benefit for respiratory infections.
Area of Science:
- Pediatrics
- Nutritional Science
- Infectious Disease
Background:
- Previous research suggested potential benefits of vitamin C for managing the common cold.
- Self-observation and earlier studies indicated vitamin C's usefulness.
Purpose of the Study:
- To rigorously evaluate the efficacy of vitamin C in preventing and treating the common cold in children.
- To assess the impact of vitamin C on illness incidence, duration, and complications.
Main Methods:
- A double-blind, placebo-controlled trial was conducted involving 868 children.
- Participants were randomized to receive either vitamin C or a placebo.
- Key metrics included illness episodes, duration, and bacterial cultures.
Main Results:
- No significant differences were observed in the number of children falling ill, the number of illness episodes, or the mean duration of illness between the vitamin C and placebo groups.
- While vitamin C supplementation led to higher plasma ascorbic acid levels, it did not reduce the overall rate of complicated illness.
- Interestingly, children with higher plasma ascorbic acid concentrations experienced longer mean illness durations.
Conclusions:
- Vitamin C does not appear to be an effective prophylactic or therapeutic agent for managing the common cold (upper respiratory illness) in children.
- The findings challenge previous assumptions about vitamin C's role in cold management.
- Further research may be needed to understand the observed correlation between high vitamin C levels and prolonged illness.
Abstract:
To evaluate earlier observations, including our own, showing usefulness of vitamin C for managing the common cold, we performed a double-blind trial of vitamin C versus placebo in 868 children. There was no difference in number becoming ill (133 versus 129), number of episodes (166 versus 159) or mean illness duration (5.5 versus 5.8 days) between the groups. Children receiving vitamin C had fewer throat cultures yielding beta-hemolytic streptococcus (six versus 13, P less than 0.10), but no difference in overall complicated illness rate (24 versus 25). Plasma ascorbic acid levels were higher in the vitamin group 24 to 26 hours after supplementation (1.28 versus 1.04 mg per 100 ml, P less than 0.01). Children with high plasma ascorbic acid concentrations had longer mean illness (6.8 versus 4.0 days, P less than 0.05) than those with low levels. Vitamin C does not seem to be an effective prophylactic or therapeutic agent for upper respiratory illness.