<prompt> Which vitamin deficiency causes glossitis and cheilosis?ThiaminRiboflavinFolic acidVitamin A  <response>: Riboflavin deficiency causes glossitis and cheilosis. Riboflavin Deficiency: a.Causes: Natural deficiency of riboflavin in man is uncommon because riboflavin is synthesized by the intestinal flora. Riboflavin deficiency usually accompanies other deficiency diseases such as beriberi, pellagra and kwashiorkor. b.Manifestations: Symptoms are confined to skin and mucous membranes. i. Glossitis Greek, glossa tongue. ii. Magenta coloured tongueiii. Cheilosis Greek, cheilos lip.iv. Angular stomatitis inflammation at the corners of mouth. v. Circumcorneal vascularization. vi. Proliferation of the bulbar conjunctival capillaries is the earliest sign of riboflavin deficiency. Reference: Vasudevan Textbook of Biochemistry pg no. 393 