What are the two categories of vitamins?

The correct classification of vitamins into two categories is based on their solubility, which is either fat-soluble or water-soluble.

Fat-soluble vitamins, which include vitamins A, D, E, and K, are absorbed with dietary fat and can be stored in the body's fatty tissues and liver. This ability to store allows the body to utilize these vitamins over time, but it also means that excessive intake can lead to toxicity.

Water-soluble vitamins, such as the B-complex vitamins and vitamin C, dissolve in water. They are not stored in significant amounts in the body; any excess is usually excreted in urine. This means that these vitamins need to be consumed regularly in the diet to maintain adequate levels.

Understanding the difference between these two categories is crucial for proper nutrition, as it influences how vitamins are consumed, their storage in the body, and the risk of deficiencies or excesses. The other options do not accurately represent the primary classification system used for vitamins, reinforcing the importance of focusing on solubility for understanding their roles and management in nutrition.