Which vitamins are considered water-soluble vitamins?

Water-soluble vitamins are essential nutrients that dissolve in water and are readily absorbed into body tissues. The primary water-soluble vitamins include vitamin C and the entire B-complex group, which consists of several vitamins such as B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folate), and B12 (cobalamin). Because they are water-soluble, these vitamins are not stored in significant amounts in the body and need to be consumed regularly in the diet.

In contrast, the other options listed include vitamins A, D, E, and K, which are fat-soluble vitamins. These vitamins require dietary fat for absorption and can be stored in the body's fatty tissues and liver, which distinguishes them from the water-soluble group. This difference in solubility, storage, and dietary requirements is critical for understanding their roles in human health.