Answer the question on basis of passage given below:

Vitamins represent a group of organic compounds which are needed in small amount for the healthy growth and maintenance of our body. These are not synthesized by the body and are supplied in the diet. The deficiency of vitamins can be supplemented with medicines.

Water soluble vitamins are excreted out of our body through urination. Identify the vitamin which is stored in our body for a number of years?

Vitamin \(B_{12}\)

The correct answer is option 3. Vitamin \(B_{12}\). 

Let us look into why Vitamin \(B_{12}\) (Cobalamin) stands out among water-soluble vitamins for its storage in the body:

1. Storage in the Liver:

Unlike other water-soluble vitamins that are primarily excreted via urine when consumed in excess, Vitamin \(B_{12}\) has a unique mechanism of storage in the body. Vitamin \(B_{12}\) is primarily stored in the liver, with smaller amounts stored in other tissues such as muscle. The liver has the capacity to store several years' worth of vitamin \(B_{12}\) supply, making it distinct from other water-soluble vitamins that are not stored to such an extent.

2. Long-Term Storage:

The ability of the liver to store Vitamin B12 for an extended period is crucial for maintaining adequate levels in the body, especially during times of low dietary intake or increased demand. This long-term storage capacity provides a buffer against short-term fluctuations in dietary intake of Vitamin \(B_{12}\). It also ensures that the body has a reservoir of Vitamin \(B_{12}\) for use in various physiological processes over an extended period.

3. Importance for Physiological Functions:

Vitamin \(B_{12}\) plays essential roles in various physiological processes, including:

Formation of red blood cells:  Vitamin \(B_{12}\) is necessary for the production of healthy red blood cells. Deficiency can lead to megaloblastic anemia, characterized by large, immature red blood cells.

Neurological function:  Vitamin \(B_{12}\) is crucial for the maintenance of the nervous system. Deficiency can lead to neurological disorders such as peripheral neuropathy and cognitive impairment.

DNA synthesis:  Vitamin \(B_{12}\) is involved in the synthesis of DNA, the genetic material of cells. It plays a role in cell division and growth.
 
4. Dietary Sources and Absorption:

Vitamin \(B_{12}\) is primarily obtained from animal-derived foods such as meat, fish, eggs, and dairy products. Plant-based foods do not naturally contain significant amounts of Vitamin \(B_{12}\), making it essential for vegetarians and vegans to supplement or fortify their diets. Absorption of Vitamin \(B_{12}\) from food requires adequate stomach acid and the presence of intrinsic factor, a protein produced by the stomach lining. Intrinsic factor binds to Vitamin \(B_{12}\) in the stomach, facilitating its absorption in the small intestine. Conditions that affect stomach acid production or intrinsic factor secretion can impair the absorption of Vitamin \(B_{12}\), leading to deficiency even in individuals with an adequate dietary intake.

5. Manifestation of Deficiency:

Due to its long-term storage in the liver, Vitamin \(B_{12}\) deficiency may not manifest for several years, even in cases where dietary intake is insufficient. Once the body's stores of Vitamin \(B_{12}\) are depleted, deficiency symptoms can develop rapidly and may include fatigue, weakness, pale skin, shortness of breath, neurological symptoms (such as numbness and tingling in the hands and feet), and cognitive impairment.

In summary, Vitamin \(B_{12}\) distinguishes itself among water-soluble vitamins due to its unique storage in the liver, providing a long-term reservoir for maintaining adequate levels in the body. This storage capacity is essential for ensuring optimal physiological functions, including red blood cell formation, neurological function, and DNA synthesis. However, it also underscores the importance of maintaining a consistent intake of Vitamin \(B_{12}\)-rich foods or supplements to prevent deficiency in the long term.