Question

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

• A. Vitamin B₂
• B. Vitamin B₁
• C. Vitamin B₆
• D. Vitamin B₁₂

Hint:

Vitamin Bsubscript{12} is unique among water-soluble vitamins as it is stored in the body for a long time.

Answer 1

The Correct Option is D

Step 1: Understanding Water-Soluble Vitamins 
Water-soluble vitamins (B-complex and C) dissolve in water and are excreted in urine.
However, Vitamin B₁₂ is an exception. 
Step 2: Storage of Vitamin B₁₂ 
Unlike other B vitamins, B₁₂ is stored in the liver.
It plays a vital role in red blood cell formation and neurological functions.
Final Answer: Vitamin B₁₂ is water-soluble but not excreted easily. 
 

Answer 2

Vitamin B₁₂ is a water-soluble vitamin that is not excreted easily.

Unlike most water-soluble vitamins, which are readily excreted through urine if consumed in excess, Vitamin B₁₂ (cobalamin) has a unique mechanism in the body that allows it to be stored, primarily in the liver, for long periods. This storage capability prevents its rapid loss through excretion.

Vitamin B₁₂ plays a vital role in red blood cell formation, neurological function, and DNA synthesis. Due to its complex structure and the body's ability to recycle and store it, deficiency symptoms often take years to appear, and toxicity from excess intake is rare. This characteristic distinguishes Vitamin B₁₂ from other water-soluble vitamins like Vitamin C and the B-complex vitamins, which need to be replenished regularly.