Final answer:
Fruits do not serve as a significant dietary source of sterols, whereas animal products, vegetables, and nuts do contain sterols such as cholesterol and phytosterols.
Step-by-step explanation:
All of the following are dietary sources of sterols EXCEPT: fruits. Sterols, which include cholesterol and phytosterols, are present in various foods. Cholesterol is abundant in animal products such as meat, whole milk, lard, butter, and cheese. Vegetables contain phytosterol, which helps in reducing serum total cholesterol. Nuts can provide essential fatty acids and are considered superior dietary sources because they contain more polyunsaturated fatty acids and less cholesterol. However, fruits, while beneficial for their vitamins and minerals like potassium and their ability to prevent conditions such as scurvy, do not serve as a significant source of sterols.