The Nutritional Biochemistry of Chromium(III) - Survival-training.info

Chapter 2Basis for dietary recommendations for chromiumBarbara J. StoeckerDepartment of Nutritional Sciences, Oklahoma State University, Stillwater, OK 74078INTRODUCTIONThe development of the Dietary Reference Intakes (DRIs) was a collaborative effortbetween American and Canadian scientists; parent organizations were the Food andNutrition Board of the Institute of Medicine and Health Canada. The DRI for chromiumwas established in 2001 under the auspices of the Food and Nutrition Board’s StandingDRI Committee and involved extensive input from the Panel on Micronutrients, theSubcommittee on Upper Reference Levels of Nutrients, and the Subcommittee on theInterpretation and Uses of the DRIs [1].Because of the paucity of available data on metabolic responses to usual dietaryintakes of chromium, recommendations were established as Adequate Intakes (AI) fordifferent age/gender groups rather than as Estimated Average Requirements (EAR) withresulting Recommended Dietary Allowances (RDA). Based on policy and guidelines forestablishing the DRIs, if data are insufficient for establishing a nutrient intake estimatedto meet the needs of half of the healthy individuals in a life stage and gender group(EAR), it is not possible to establish an RDA. There was only one study in whichparticipants were fed a controlled low-chromium diet [2], and this study did not allowthe determination of the point at which half of the participants were chromium deficient.Therefore, the chromium recommendation is expressed as an AI and is based on theavailable data on chromium in well-balanced diets.The chromium AIs represent a substantial decrease from the Estimated Safe andAdequate Daily Dietary Intake (ESADDI) for chromium first established in 1980 [3]and retained in the 10th edition of the Recommended Dietary Allowances publishedin 1989 [4]. In the late 1970s when the first ESADDI for chromium was established,almost all data on chromium in blood, urine, and foods were erroneous. Chromiumconcentrations in biological samples are too low to be determined by flame atomicspectrophotometer and graphite furnace atomic absorption spectrophotometers were notwidely available; furthermore, prior to 1980, samples were typically contaminated duringcollection. There was a general lack of awareness of the precautions needed for handlingsamples for ultratrace element analyses. Blood samples acquired chromium by beingThe Nutritional Biochemistry of Chromium(III)John B. Vincent (Editor)ISBN: 0-444-53071-1© 2007 Published by Elsevier B.V.