Which vitamin is NOT a water-soluble vitamin?

Vitamin A is categorized as a fat-soluble vitamin, which means it is absorbed in the intestines along with dietary fat and can be stored in the body's fatty tissues and liver. This storage capability allows the body to maintain reserves of Vitamin A, which is crucial for functions like vision, immune response, and skin health. In contrast, water-soluble vitamins, such as biotin, thiamin, and folate, do not have the same storage capabilities and typically must be consumed more regularly, as they are excreted through urine when in excess. Understanding this classification of vitamins is essential for recognizing their unique roles and requirements in nutrition and health management.