This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and health, Subject name: Social & Preventive Medicine
Casal's Necklace is seen in deficiency of 
Select and explain. 
A. Vitamin A, B. Vitamin B3, C. Vitamin B6, D. Vitamin D
B: Vitamin B3
Answer: B: Vitamin B3 
Explanation: Pellagra Pellagra occurs due to Vitamin B3 (Niacin) deficiency Pellagra is characterized by by 4D's : 1.Diarrhoea 2.Dermatitis 3.Dementia 4.Death. Skin rash in Pellagra may appear as pigmented and scaly in areas exposed to sunlight. Especially neck when it is known as 'Casal's Necklace' Ref: Park 25th edition Pgno : 657 Harrison's 15th edition Pgno : 463