Christopher A. Taylor

Vitamin C Deficiency and Depletion in the United States: The Third National Health and Nutrition Examination Survey, 1988 to 1994

OBJECTIVES We sought to determine prevalence rates of vitamin C deficiency and depletion in the United States. METHODS We used data from the Third National Health and Nutrition Examination Survey to assess intake of dietary, supplemental, and serum vitamin C. RESULTS Mean intakes and serum levels of vitamin C were normal; however, vitamin C deficiency and depletion were common (occurring among 5%-17% and 13%-23% of respondents, respectively). Smokers, those who did not use supplements, and non-Hispanic Black males had elevated risks of vitamin C deficiency, while Mexican Americans had lower risks. CONCLUSIONS Health professionals should recommend consumption of vegetables and fruits rich in vitamin C and should recommend supplementation for individuals at risk of vitamin C deficiency.

Intakes of vitamin C, vegetables and fruits: Which schoolchildren are at risk?

OBJECTIVE The purpose of this study was to determine vitamin C intakes among American schoolchildren. We investigated the leading sources of vitamin C in childrens diets, the leading vegetables and fruits consumed by children and differences in dietary intake associated with vitamin C consumption. METHODS Data from 1,350 7- to 12-year-old and 908 13- to 18-year-old schoolchildren were obtained from the 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII). The children were stratified by age and gender and then split into three vitamin C consumption groups based upon two 24-hour recalls: low (0 to 30.0 mg), marginal (30.1 to 59.9 mg), and desirable (>60.0 mg). Data were analyzed by tabulation and by ANOVA followed by post hoc Scheffes test. Outcome measures included food groups and energy-adjusted intakes of micro- and macronutrients. RESULTS Among the 7- to 12-year-olds, 12% of boys and 13% of girls had mean vitamin C intakes that were less than 30 mg/day, and, among 13- to 18-year-olds, 14% of boys and 20% of girls had low vitamin C intakes. In addition to consuming significantly more vitamin C, children with desirable vitamin C intakes also consumed significantly more (p <0.001) energy-adjusted folate and vitamin B6; children with low vitamin C intakes tended to have significantly greater (p <0.001) energy-adjusted intakes of fat and saturated fat. Children with desirable vitamin C intakes consumed significantly more (p <0.006) high-vitamin C fruit juice, low-vitamin C vegetables and whole milk. Children with low vitamin C intakes on average consumed two daily servings of vegetables and fruits, of which less than 1/5 of a serving was citrus, while children with desirable vitamin C intakes consumed an average of one daily serving of citrus. CONCLUSIONS A considerable number of children drastically under-consumed vitamin C and total vegetables and fruits. Overall, children with desirable vitamin C intakes had healthier diets, including more milk and vegetables, than did their peers with low vitamin C intakes. Health care professionals should continue to promote at least five daily servings of vegetables and fruits and should advise parents that at least one of these should be rich in vitamin C.

Low intakes of vegetables and fruits, especially citrus fruits, lead to inadequate vitamin C intakes among adults.

Objective: To determine vitamin C intakes among adults and to identify differences in dietary intake associated with vitamin C consumption.Design: This cross-sectional study compared vitamin C intake, nutrient intake, and food group choices of adults with low (<30 mg/d), marginal (30–60 mg/d), and desirable (>60 mg/d) vitamin C intakes.Subjects: Data from 2472 men and 2334 women aged 25–75 y were obtained from the 1994–1996 Continuing Survey of Food Intakes by Individuals (CSFII).Results: Overall, 18% of the sample had low vitamin C intakes, 24% had marginal intakes, and 58% had desirable intakes. In addition to consuming less vitamin C, adults with low vitamin C intakes consumed significantly less (P≤0.001) energy-adjusted (ie nutrient/1000 kcal) folate, fiber, β-carotene, and vitamin B6, and significantly more (P<0.001) fat. Compared to adults with low intakes, adults with desirable vitamin C intakes consumed significantly more (P≤0.001) high-vitamin C fruit juice and low-vitamin C vegetables, while consuming significantly less (P≤0.009) soft drinks, coffee/tea and alcoholic beverages. On average, adults with desirable vitamin C intakes consumed more than five daily servings of vegetables and fruits, of which more than one was citrus. Adults with low and marginal vitamin C intakes consumed less than one-fifth of a serving of citrus.Conclusions: A considerable number of adults under-consume vitamin C and total vegetables and fruits. Nutritionists should continue to promote five to nine daily servings of vegetables and fruits, at least one of which should be rich in vitamin C.European Journal of Clinical nutrition (2000) 54, 573–578

Low Vitamin C Intakes Among American Adults: Who Is At Risk?

Abstract Poor consumption of vitamin C-rich foods has led to a rise in subclinical vitamin C deficiency in the United States. We used the 1994-96 Continuing Survey of Food Intakes by Individuals to assess vitamin C intake in a sample of 25- to 90-year-olds (n=5290). After stratifying by age and sex, we divided the sample into three groups based upon mean vitamin C intake: low (0-30mg), marginal (30.1-60mg), and desirable (>60.1 mg). ANOVA with post hoc Scheffes analyses was used for comparisons. Across all age groups, leading sources of vitamin C were vitamin C-rich fruit juices, low-vitamin C vegetables, vitamin C-rich fruits, and vitamin C-fortified fruit drinks. On average, 17% of adults had low vitamin C intakes. Among males, the highest percentage with low vitamin C intake was the elderly (21% of 75- to 90-year-olds), whereas among females it was younger women (23% of 25- to 44-year-olds). Across age categories and sexes, we found consistent dietary differences. Adults with desirable vitamin C intake consumed significantly more vitamin C-rich fruit juice, low-vitamin C vegetables, beef and ground beef dishes, low-fiber breads/rolls, condiments, and french fries. Those with low vitamin C intake consumed significantly more soft drinks, table sweeteners, coffee/tea, and alcohol. Regarding nutrients, adults with desirable vitamin C intake consumed significantly more energy-adjusted fiber, iron, magnesium, folate, and vitamin B 6 , A, and C; those with low vitamin C intakes consumed significantly more energy-adjusted cholesterol, saturated fat, and total fat. Our data indicate that a considerable proportion of American adults are drastically under-consuming vitamin C and have an increased risk for atherosclerosis due to low antioxidant intakes and high intakes of saturated fat. Adults who did consume desirable vitamin C relied upon juice and a variety of low vitamin C-containing foods. Further education with the Food Guide Pyramid—emphasizing vegetables and fruits rich in vitamin C—is warranted.