Because chromium in foods cannot be analyzed from existing databases, paired food or duplicate meal analyses are required, and data are available from only a few laboratories and locations. In one study, self-selected diets were composited for 7 days and analyzed for chromium content. The mean chromium intake of 10 adult men was 33 μg/day (range 22 to 48 μg/day), and the chromium intake for 22 women was 25 μg/day (range 13 to 36 μg/day) (Anderson and Kozlovsky, 1985). Mean chromium intake was approximately 15.6 μg/1,000 kcal. The chromium content of 22 daily diets, designed by nutritionists to be well balanced, ranged from 8.4 to 23.7 μg/1,000 kcal with a mean of 13.4 μg/1,000 kcal (Anderson et al., 1992). In another study, a group of adults self-selected a mean chromium intake of 14.4 μg/1,000 kcal (Anderson et al., 1991), and lactating mothers consumed foods containing 18.8 μg/1,000 kcal (Anderson et al., 1993a). Chromium intake studies in Canadian women suggest median chromium intakes two or more times higher than the values reported from the eastern United States (Gibson and Scythes, 1984; Gibson et al., 1985). Further research is needed to define the contributions of differences in dietary patterns, regional variation in food chromium concentrations, and possible sample contamination in these disparate values.
Derivation of dietary intake based on duplicate meal analyses assumes that subjects do not change their intakes because of the collection; however, this assumption may underestimate actual food intake (Kim et al., 1984). In a controlled study in which actual energy requirements of subjects were estimated, Anderson and coworkers (1993b) found that the ratio of energy requirement to energy intake measured from the duplicate meal analysis was 1.29 for women and 1.46 for men. Applying these correction factors to chromium intakes would increase the estimated chromium intake of women in this study from 23.1 to 28.7 μg/day and of men from 38.8 to 54.1 μg/day. This correction raises the question of whether some of the current estimates of dietary chromium intake are too low.
In 1986, 8 percent of adults consumed supplements that contained chromium (Moss et al., 1989; see Table 2-2). Based on the Third National Health and Nutrition Examination Survey data, the median supplemental intake of chromium was 23 μg/day for those