Dietary vitamin C intake and concentrations in the body fluids and cells of male smokers and nonsmokers

Inhaled cigarette smoke releases a variety of oxidizing agents. Ascorbic acid is recognized as an important biological antioxidant. To better characterize the antioxidant protective role of ascorbic acid, a comparison of ascorbic acid concentrations in plasma, leukocytes, bronchoalveolar lavage fluid and alveolar macrophages from a homogeneous group of healthy male smokers (n = 10) and nonsmokers (n 14) was investigated. The resulting ascorbic acid contents were (means +/- SD) 91 +/- 25 (n = 10) and 87 +/- 25 (n = 14) micromole/L in plasma, 2.09 +/- 0.62 (n = 7) and 2.12 +/- 0.77 (n = 11) micromole/10(9) cells in mononuclear leukocytes, 3.2 +/- 2.2 (n = 10) and 1.7 +/- 1.5 (n = 13) micromole/L in bronchoalveolar lavage fluid and 3.4 +/- 2.3 (n = 8) and 1.6 +/- 1.3 (n = 6) micromole/10(9) cells in alveolar macrophages from smokers and nonsmokers, respectively. Mean daily dietary vitamin C intake was 116 +/- 68 and 107 +/- 59 mg/d for smokers and nonsmokers, respectively. The ascorbic acid contents of bronchoalveolar lavage [3.9 +/- 1.9 micromole/L (n = 8)] and alveolar macrophages [4.1 +/- 2.1 micromole/10(9) cells (n = 6)] of smokers consuming 15 to 20 cigarettes/d were significantly higher (P < 0.05) than those of nonsmokers. The increased content of ascorbic acid in bronchoalveolar lavage and in alveolar macrophages of smokers compared with nonsmokers may reflect a defensive mechanism against free radical species derived from cigarette smoke.