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TABLE 3-9 continued
Vitamin	Alternative Names	1980 RDA, amount per daya	Major Food Sources	Food Supply, Intakes, and Nutritional Status
Vitamin C (continued)		Pregnant women, +20 mg Lactating women, +40 mg	NFCS indicated that 73% of the vitamin C intake came from fruits and vegetables.	men 19 to 50 years old, 104 mg.d In the1977-1978 NFCS, the mean intake (82 mg/day) for the entire survey population was above the RDA. Dietary levels were positively associated with economic status.e JNMEC noted that the 1976-1980 NHANES found that 3% of the survey population 3 to 74 years of age had low serum vitamin C levels. Subpopulations of adults who were at high risk of poor vitamin C status included consumers of diets low in vitamin C, cigarette smokers, and the very poor. A higher proportion of males than females had low serum vitamin C levels. Vitamin C is accorded public health monitoring priority because of low serum vitamin C levels and low intakes in some population groups.f
a From NRC (1980). Comparisons with the RDA are intended to indicate relative amounts; intakes below the RDA should not be construed as inadequate. b RE = retinol equivalents. One RE = 1 µg of retinol; 6 µg of b1-carotene; 12 µg of other provitamin A carotenoids; 3.33 IU of vitamin activity from retinol; 10 IU of vitamin A activity from b-carotene. c Historical food supply data from USDA (see Table 3-3). d USDA (1986b, 1987a). e USDA (1984). f DHHS/USDA (1986). g a-TE = a-tocopherol equivalent; 1 mg d-a-tocopherol = 1a-TE. h NE = niacin equivalents. 1 NE = 1 mg niacin or 60 mg of dietary tryptophan.