Acquired kidney and liver diseases are relatively common diseases that can raise the potential for nutrient intoxication. For example, high-protein diets increase glomerular blood flow and the blood pressure gradient across the glomerular capillary wall in the kidney, which can result in injury to membranes. Likewise, the liver can increase nutrient intoxication because it is involved in the intermediary metabolism of many nutrients, serves as the storage organ for many nutrients, and is important in the biotransformation and excretion of nutrients. In this paper, vitamin A serves as an example to illustrate how kidney disease and liver disease can increase a single nutrient's toxicity.