Night blindness is caused by deficiency of which vitamin?

Night blindness is caused by deficiency of which vitamin?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin K

Answer: (A)

Night vision relies on a pigment in the retina called rhodopsin, which requires vitamin A to form. Vitamin A acts as the building block (retinal) for rhodopsin, so when vitamin A is deficient, the eye can’t replenish this pigment efficiently. That makes it hard for the rods in the retina to adjust from bright to dim light, leading to night blindness. Other vitamins don’t play that specific role in the visual pigment, so their deficiencies don’t produce this symptom. Vitamin A comes from animal sources as retinol and from plants as beta-carotene, and deficiency can also lead to other eye problems if it worsens.

Night vision relies on a pigment in the retina called rhodopsin, which requires vitamin A to form. Vitamin A acts as the building block (retinal) for rhodopsin, so when vitamin A is deficient, the eye can’t replenish this pigment efficiently. That makes it hard for the rods in the retina to adjust from bright to dim light, leading to night blindness. Other vitamins don’t play that specific role in the visual pigment, so their deficiencies don’t produce this symptom. Vitamin A comes from animal sources as retinol and from plants as beta-carotene, and deficiency can also lead to other eye problems if it worsens.