Keratinising metaplasia of salivary glands results due to deficiency of: (A) Vitamin A, (B) Thiamine, (C) Riboflavin, (D) Vitamin E
Answer is A. Vitamin A deficiency produces keratinizing metaplasia of the normally columnar ductal epithelium in the major and minor salivary glands.
Ref : Handbook of Experimental  Stomatology,edited by Samuel Dreizen, Barnet M. Levy.