Night blindness is caused by deficiency of which vitamin?

Night blindness is caused by deficiency of which vitamin?

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

Answer: (A)

Night vision in dim light relies on a pigment in the rods of the retina called rhodopsin, and making this pigment requires a form of vitamin A (retinal). When vitamin A is deficient, rhodopsin can’t be regenerated efficiently, so the eyes struggle to adapt to low light and night vision deteriorates. Other vitamins don’t have this direct role in the retinal processes needed for seeing in the dark, so their deficiencies don’t typically cause night blindness. Vitamin A is a fat-soluble nutrient stored in the liver, and it can be obtained from animal sources or converted from carotenoids in colorful fruits and vegetables.

Night vision in dim light relies on a pigment in the rods of the retina called rhodopsin, and making this pigment requires a form of vitamin A (retinal). When vitamin A is deficient, rhodopsin can’t be regenerated efficiently, so the eyes struggle to adapt to low light and night vision deteriorates. Other vitamins don’t have this direct role in the retinal processes needed for seeing in the dark, so their deficiencies don’t typically cause night blindness. Vitamin A is a fat-soluble nutrient stored in the liver, and it can be obtained from animal sources or converted from carotenoids in colorful fruits and vegetables.