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 less than or equal to 0.001) energy-adjusted (ie nutrient/1000 kcal) folate, fiber, beta-carotene, and vitamin B-6, and significantly more (P < 0.001) fat. Compared to adults with low intakes. adults with desirable vitamin C intakes consumed significantly more (P less than or equal to 0.001) high-vitamin C fruit juice and low-vitamin C vegetables, while consuming significantly less (P less than or equal to 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.