Issues and Opinions in Nutrition Utility and Importance of Gene Knockout Animals For Nutritional and Metabolic Research1,2

The importance of many dietary constituents in mainte-nance of health is obvious. While deficiencies in dietary intake of specific nutrients may be detrimental to growth, reproduction and immunity, excessive amounts of specific nutrients in the diet can also lead to disease states. For example, increased intake of dietary fat and cholesterol is associated with hyperlipidemia and an increased risk of coronary heart disease (Keys 1970). Excessive intake of vitamin D has also been shown to result in soft-tissue calcification and renal calculi. However, it must be noted that while the correlation exists between increase nutrient uptake and specific diseases, the response of a given indi-vidual is quite variable. These individual variations in di-etary responsiveness are likely due to the different genetic composition of each individual. Numerous genetic factor