Deficiency of which of the following vitamins causes increased fragility of RBC's and muscular weakness?

Question

Accepted Answer

Deficiency of Vitamin E is the correct answer for the question regarding increased fragility of RBCs and muscular weakness. Here is a detailed explanation supporting this:

1. **Explanation for Option 2 (Vitamin E):**
   - Vitamin E is a fat-soluble antioxidant that plays a crucial role in protecting cell membranes from oxidative damage. It is particularly important for the integrity of red blood cells (RBCs) and muscle cells.
   - A deficiency in Vitamin E can lead to increased oxidative stress, which causes damage to the cell membranes of RBCs, making them more fragile and prone to hemolysis (breaking down). This results in conditions such as hemolytic anemia.
   - Additionally, Vitamin E deficiency can lead to muscular weakness and neurological problems because muscle cells are also susceptible to oxidative damage without adequate antioxidant protection.

2. **Explanation for why other options are incorrect:**

- **Option 1 (Vitamin K):**
     - Vitamin K is primarily involved in blood clotting processes. A deficiency in Vitamin K leads to bleeding disorders due to impaired clotting, not increased fragility of RBCs or muscular weakness.
   
   - **Option 3 (Vitamin $B_{12}$):**
     - Vitamin $B_{12}$ is essential for DNA synthesis and neurological function. Its deficiency leads to megaloblastic anemia and neurological symptoms, but not specifically to increased fragility of RBCs or muscular weakness as seen with Vitamin E deficiency.
   
   - **Option 4 (Vitamin $B_{6}$):**
     - Vitamin $B_{6}$ is involved in amino acid metabolism and neurotransmitter synthesis. Deficiency can lead to anemia and neurological symptoms, but it does not specifically cause increased fragility of RBCs or muscular weakness in the same way Vitamin E deficiency does.

In conclusion, Vitamin E is the correct answer because its deficiency directly leads to increased fragility of RBCs and muscular weakness due to its role as an antioxidant protecting cell membranes from oxidative damage.