Cadmium bioavailability
1983
Fox, M.R. Spivey
Extract: Cadmium (Cd) slowly accumulates in the liver and kidney and has a long biological half-life (estimated to 2-3 decades in the kidney). If the kidney Cd concentration reacxhes a critically high level, proximal tubular damage results, which can be followed by severe bone mineral loss. There are only a few measurements of Cd bioavailability in foods; however, the data are indicative of lower utilization from foods than from inorganic salts. In animal tissues, Cd is bound primarily to a heat-resistant small protein with a high cysteine content (metallothioein), whereas little is known about the form in which Cd occurs in the edible parts of plants. Low intakes of many nutrients exacerbate the effects of Cd, and supplemental intakes are protective. Newborn and young animals absorb much higher quantities of Cd than adults. There is some evidence in animals that females may be more adversely affected than males. Itai-itai disease, a painful disease with kidney damage and bone demineralization, occurred in elderly Japanese women who had borne several children, and who were exposed to Cd via food and drinking water. Inasmuch as Cd in the US food supply affords an estimated safety factor of only 4- to 15-fold, it is important to establish factors that affect the bioavailability of Cd from foods. (author/wz)
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