Which of the following is a water soluble vitamin, that is not excreted easily ?

Vitamin B₁₂

Explanation:

Water-soluble vitamins include the B group vitamins and vitamin C. These vitamins dissolve in water and are typically excreted through urine when consumed in excess. However, an exception to this rule is vitamin B₁₂, which is not easily excreted.

Vitamin B₁₂ is unique because it is stored in the liver for extended periods, unlike other water-soluble vitamins. This storage capacity reduces its excretion rate, making it an exception among water-soluble vitamins. The absorption of vitamin B₁₂ is facilitated by a protein called intrinsic factor, which helps the vitamin bind to receptors in the small intestine.

Conceptual Note:

Water-soluble vitamins are essential for various metabolic processes. For example:

• Vitamin B₁ (Thiamine): Plays a role in energy metabolism and nerve function.
• Vitamin B₂ (Riboflavin): Supports energy production and skin health.
• Vitamin B₆ (Pyridoxine): Involved in amino acid metabolism and red blood cell production.
• Vitamin B₁₂ (Cobalamin): Crucial for red blood cell formation, DNA synthesis, and nerve health.