Which vitamin cannot be stored in the human body?

Vitamins are essential nutrients required by the human body in small amounts for various physiological functions. They are classified into fat-soluble vitamins and water-soluble vitamins based on how they are absorbed, transported, and stored. Fat-soluble vitamins, such as Vitamin A, D, E, and K, can be stored in the liver and fatty tissues for later use. Water-soluble vitamins, including Vitamin C and the B-complex vitamins, cannot be stored in large amounts and need to be replenished regularly through diet.

Among all vitamins, Vitamin C (also known as ascorbic acid) is the most notable example of a vitamin that cannot be stored in the human body. It is water-soluble, which means any excess amounts are excreted through urine. Because the body cannot store Vitamin C, it must be consumed daily from sources such as citrus fruits, strawberries, kiwi, guava, and green leafy vegetables.

Vitamin C is essential for several important functions in the body. It acts as a powerful antioxidant, protecting cells from oxidative damage. It is also crucial for the synthesis of collagen, which supports skin, blood vessels, bones, and cartilage. Additionally, Vitamin C improves iron absorption from plant-based foods and supports the immune system, helping the body fight infections.

In contrast, fat-soluble vitamins like Vitamin D or Vitamin K are stored in the liver and fatty tissues, so the body can access them when needed. This storage capability allows humans to maintain adequate levels even if intake is inconsistent for short periods.

Understanding the difference between water-soluble and fat-soluble vitamins is fundamental in biology and nutrition. It explains why a daily intake of Vitamin C is necessary to maintain health and prevent deficiencies such as scurvy, a condition caused by prolonged lack of Vitamin C.