This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Minerals, Subject name: Biochemistry
Excess of avidin causes deficiency of: 
Select and explain. 
A. Folate, B. Choline, C. Vitamin B12, D. Biotin
D: Biotin
Answer: D: Biotin 
Explanation: Excess consumption of raw eggs, which contains a protein 'avidin' - a biotin binding protein leads to biotin deficiency When cooked, avidin is paially denatured and its binding to biotin is reduced. So cooked egg whites are safe to consume.