Which vitamins are characterized by their ability to dissolve in water?

Water-soluble vitamins are characterized by their ability to dissolve in water. This means that they can be absorbed directly into the bloodstream from the intestines without the need for the presence of fats. These vitamins include the B-complex vitamins and vitamin C. Because they dissolve in water, they are generally not stored in large amounts in the body; instead, excess amounts are excreted through urine. This highlights their need for regular consumption in the diet to maintain adequate levels for bodily functions.

In contrast, fat-soluble vitamins, such as vitamins A, D, E, and K, require dietary fat for absorption and can be stored in the body's fatty tissues and liver. The term "mineral vitamins" is misleading, as minerals are inorganic elements and are not classified as vitamins. Essential vitamins refer to those that the body cannot synthesize on its own and must be obtained through the diet, which includes both water-soluble and fat-soluble vitamins. Therefore, the defining characteristic of being soluble in water distinctly identifies water-soluble vitamins as the correct answer in this context.