In what do vitamins A, D, E, and K need to dissolve in the body?

Vitamins A, D, E, and K are classified as fat-soluble vitamins. This means that in order for the body to absorb and utilize these vitamins effectively, they need to dissolve in dietary fat. Once consumed, these vitamins are incorporated into micelles and subsequently absorbed along with fat through the intestinal walls. This absorption process is essential for the vitamins to be transported within the body, as they are stored in the liver and fatty tissues until needed.

In contrast, water-soluble vitamins (like the B vitamins and vitamin C) dissolve in water and can be easily excreted through urine if taken in excess. The requirement for fat-soluble vitamins to dissolve in fat underscores the importance of including healthy fats in the diet to ensure proper nutrient absorption. Thus, the correct answer emphasizes the significant role of fats in facilitating the uptake of these essential vitamins in the human body.