Social & Preventive Medicine Prevalence of vitamin-A deficiency in a community is assessed as the following: A Night blindness-10% B Corneal ulcer-0.1% C Bitot spots-0.5% D Decreased serum retinol level-0.05% 💡 Explanation Prevalence of vitamin-A deficiency in a community is assessed as the following: ✓ Correct Answer: C. Bitot spots-0.5%