This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition, Subject name: Pediatrics
The symptoms of dietary deficiency of niacin (which results in pellagra) will be less severe if the diet has a high content of: 
Select and explain. 
A. Tryptophan, B. Tyrosine, C. Thymine, D. Thiamine
A: Tryptophan
Answer: A: Tryptophan 
Explanation: a. Tryptophan(Ref: Nelson's 20/e p 325, Ghai 8/e p 118)Tryptophan can be converted to nicotinamide adenine dinucleotide (NAD) 60mg tryptophan gives rise to 1mg niacin.