(04-11-09) Serum vitamin C and the prevalence of vitamin C deficiency in the United States:

2003?2004 National Health and Nutrition Examination Survey (NHANES)1,2



Rosemary L Schleicher, Margaret D Carroll, Earl S Ford and David A Lacher

1 From the Division of Laboratory Sciences, National Center for Environmental Health (RLS), the Division of Health Examination Statistics, National Center for Health Statistics (MDC and DAL), and the Division of Adult and Community Health, National Center for Chronic Disease Prevention and Health Promotion (ESF), Centers for Disease Control and Prevention, Atlanta, GA.
2 Address correspondence to RL Schleicher, Centers for Disease Control and Prevention, 4770 Buford Highway, MS F55, Atlanta, GA 30341. E-mail: [email protected] .
Background: Vitamin C (ascorbic acid) may be the most important water-soluble antioxidant in human plasma. In the third National Health and Nutrition Examination Survey (NHANES III, 1988?1994), 13% of the US population was vitamin C deficient (serum concentrations <11.4 ?mol/L).
Objective: The aim was to determine the most current distribution of serum vitamin C concentrations in the United States and the prevalence of deficiency in selected subgroups.
Design: Serum concentrations of total vitamin C were measured in 7277 noninstitutionalized civilians aged 6 y during the cross-sectional, nationally representative NHANES 2003?2004. The prevalence of deficiency was compared with results from NHANES III.
Results: The overall age-adjusted mean from the square-root transformed (SM) concentration was 51.4 ?mol/L (95% CI: 48.4, 54.6). The highest concentrations were found in children and older persons. Within each race-ethnic group, women had higher concentrations than did men (P < 0.05). Mean concentrations of adult smokers were one-third lower than those of nonsmokers (SM: 35.2 compared with 50.7 ?mol/L and 38.6 compared with 58.0 ?mol/L in men and women, respectively). The overall prevalence (?SE) of age-adjusted vitamin C deficiency was 7.1 ? 0.9%. Mean vitamin C concentrations increased (P < 0.05) and the prevalence of vitamin C deficiency decreased (P < 0.01) with increasing socioeconomic status. Recent vitamin C supplement use or adequate dietary intake decreased the risk of vitamin C deficiency (P < 0.05).
Conclusions: In NHANES 2003?2004, vitamin C status improved, and the prevalence of vitamin C deficiency was significantly lower than that during NHANES III, but smokers and low-income persons were among those at increased risk of deficiency.

Source: American Journal of Clinical Nutrition, doi:10.3945/ajcn.2008.27016
Vol. 90, No. 5, 1252-1263, November 2009

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