Serum Vitamin C Levels in Users of Electronic Cigarettes, Cigarette Smokers and Nonsmokers

INTRODUCTION: The health effects from vaping electronic cigarette (e-cigarette) aerosols relative to smoking cigarettes is an area of active study. Both products contain reactive free radicals which can potentially cause oxidative stress. Cigarette smokers have depleted blood levels of the antioxidant ascorbic acid (Vitamin C). The objective of the current study is to determine if oxidants from vaping E-cigarettes reduce blood vitamin C levels. METHODS: We conducted a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES) 2017-2018. Smoking status was defined using questions on lifetime cigarette use, current smoking, recent e-cigarette use, and recent cigarette use. Exclusive e-cigarette users were those not currently smoking cigarettes but reporting e-cigarette use in the past 5 days. Current smokers affirmed all three cigarette-related questions. Vitamin C levels were classified as adequate (≥50 μmol/L) or inadequate (<50 μmol/L). All analyses were conducted in R (version 4.3.3) using the survey and nhanesA packages. We incorporated the recommended NHANES examination weights (WTMEC2YR), along with strata (SDMVSTRA) and primary sampling units (SDMVPSU), to account for NHANES's complex, multistage probability sampling design. Statistical tests included the Rao-Scott chi-square test for categorical variables. RESULTS: Blood vitamin C (μmol/L) levels were higher in nonsmokers (55.03) than in current cigarette smokers (39.02) and exclusive e-cigarette users (37.01). A higher proportion of current smokers (65%) and e-cigarette users (66%) than nonsmokers (43%) had vitamin C levels that are considered inadequate (<μ50 mol/L). CONCLUSIONS: In NHANES 2017-2018, blood vitamin C levels were similar in e-cigarette users and cigarette smokers, and lower than in nonsmokers. IMPLICATIONS: Electronic cigarettes are nicotine delivering devices that do not contain most of the numerous chemicals found in tobacco smoke. However, there may be negative health effects from free radical exposure in e-cigarette aerosols. The current study suggests that compared to nonsmokers, vaping may increase oxidative stress.