Chromium is widely distributed throughout the food supply, but many foods contribute less than 1 to 2 μg per serving (Anderson et al., 1992). Determining the chromium content in foods requires rigorous contamination control because standard methods of sample preparation contribute substantial amounts of chromium to the foods being analyzed. In addition, chromium is quite variable among different lots of foods (Anderson et al., 1992) and may be influenced by geochemical factors (Welch and Cary, 1975). Consequently dietary chromium intakes cannot be determined from any currently existing databases.

The chromium content in foods may increase or decrease with processing. Early reports indicated chromium losses when grains and sugars were refined (Anderson, 1987). However, acidic foods accumulate chromium during preparation and processing, particularly when heated in stainless steel containers (Offenbacher and Pi-Sunyer, 1983). Cereals contribute variable, but potentially important, amounts of chromium to the total diet. The chromium content of a 50 g serving (dry weight) of 43 brands of cereal varied from 0.15 to 35 μg. High-bran cereals are generally, but not always, high in chromium. The bioavailability of chromium in these cereals was not evaluated (Anderson et al., 1988a). Most dairy products are low in chromium and provide less than 0.6 μg/serving. Meats, poultry, and fish generally contribute 1 to 2 μg per serving, but processed meats are higher in chromium and may acquire it from exogenous sources. Chromium concentrations of fruits and vegetables are highly variable (Anderson et al., 1992). Some brands of beer contain significant amounts of chromium, some of which presumably is exogenous (Anderson and Bryden, 1983). Cabrera-Vique and coworkers (1997) estimated that wine provides 4.1 μg chromium daily per resident in France, with red wines having the highest concentrations. Wines have not been analyzed for chromium in the United States.