Objective: To determined the prevalence of vitamin C deficiency (plasma vitamin C concentrations less than 11.4 mumol/L) and vitamin C depletion (plasma vitamin C concentrations from 11.4 to less than 28.4 mumol/L) in an outpatient population.
Subjects and methods: A consecutive sample of patients presenting at a health maintenance organization laboratory for outpatient procedures was utilized. Plasma vitamin C concentrations were determined in 350 females and 144 males, aged 6 to 92 years (mean +/- SD: 46.7 +/- 18.7 years).
Results: The mean plasma vitamin C concentration for all subjects was 32.4 +/- 13.6 mumol/L. Mean plasma vitamin C did not vary by sex, race, or fasted state. Diabetics had a significantly lower mean plasma vitamin C concentration (25.6 +/- 10.8 mumol/L) compared to patients presenting for general check-up/gynecological exams (33.5 +/- 14.8 mumol/L) or pregnancy exams (32.4 +/- 9.7 mumol/L). Six percent of subjects had plasma vitamin C concentrations indicative of vitamin C deficiency (n = 31), and 30.4% of the sample were vitamin C depleted (n = 150). The prevalence of vitamin C deficiency or vitamin C depletion did not differ by race or visit category.
Conclusions: Surprisingly high rates of vitamin C deficiency and vitamin C depletion were evident among generally healthy, middle class patients visiting a health care facility for routine health exams, gynecological exams, and pregnancy exams.