Factors that Affect Trace Mineral Bioavailability 



It is impossible to understand mineral bioavailability 

 without considering absorption. The events involved as a 

 substance goes from its root uptake and later incorporation 

 into the foodstuff to the actual fulfillment of a particular 

 physiological function within the body of an animal are 

 divided into three domains by Rosenberg and Solomons (1984) : 

 first, the luminal events which are responsible for the 

 preparation and delivery of the substance for enterocyte 

 uptake; second, the mucosal events which determine the 

 transfer of the nutrient through the enterocyte to the 

 basolateral membrane; and finally, the postabsorption events 

 which include the transport, delivery, usage, and ultimately 

 excretion of the nutrient. 



The amount of a particular element available to the 

 animal depends on both intrinsic and extrinsic factors 

 (O'Dell, 1983) which have also been referred to as endogenous 

 and exogenous (Rosenberg and Solomons, 1984). The intrinsic 

 factors are physiological in nature and are much harder to 

 control. They include species and genotype (Kincaid et al . , 

 1976a, b) , stage of production (Berg et al . , 1963), age 

 (Schisler and Kienholtz, 1967), physiological stress (Orr et 

 al., 1990), nutritional status (Stuart et al . , 1986), and 

 intestinal well being (Bafundo et al . , 1984). The extrinsic 



