Positive Health Online

Abstract

NESS and colleagues, Institute of Public Health, University Forvie Site, Robinson Way, Cambridge UK studied the relationship between respiratory function and vitamin C levels in blood plasma.

Background

Methodology

835 men and 1025 women aged 4575 registered with GP practices in Norfolk completed a health and lifestyle questionnaire and attended a health check. The outcome measures were: forced expiratory volume in one second (FEV1); forced vital capacity (FVC); and non-fasting plasma vitamin C.

Results

Plasma vitamin C was positively correlated with both FEV1 and FVC in men, following adjustment for age and height; the association in women was weaker and not statistically significant. In men, differences in FEV1 and FVC for a 50micromol/l difference in vitamin C were 0.22 litres and 0.23 litres respectively. 12.1% of men with vitamin C levels less than or equal to 30 micromol/L had an FEV1 of less than 2 litres, whereas only 4.6% of men with vitamin C levels greater than or equal to 60 micromol/L had an FEV1 less than 2 litres.

Conclusion

These results are consistent with data from other studies of vitamin C and respiratory function and suggest that vitamin C is protective for lung function through the whole normal range of dietary intake and lung function.

References

Ness AR et al. Vitamin C status and respiratory function. Eur J Clin Nutr 50(9): 5739. Sep 1996.