The purpose of this prospective analytic study was determination of relationship between smoking and level of vitamin C in plasma and dietary intake.

Twenty one smokers and twenty two non-smokers from Shahid Beheshti University of Medical Sciences and Health Services staff were selected and pair – matched their by age , sex, occupation, education , vitamin C supplementation, history of chronic diseases, season of food consumption and mediation.

Ascorbic acid intake was estimated by using a 24-hour recall for two separate days and food frequency questionnaire for one week. The vitamin C level in plasma was measured by using 2-4 dinitropheny 1 hydrazine method. Mean level of vitamin C in plasma and intake in the two groups were not statistically significant. Mean level of vitamin C in male than and female was equivalent, but the daily intake was 24% higher in male than in female (P<0.05).

This study showed that diets rich in vitamin C could prevent reduction of vitamin C level in plasma of smokers.