In humans , signs and symptoms of riboflavin deficiency ( ariboflavinosis ) include cracked and red lips , inflammation of the lining of mouth and tongue , mouth ulcers , cracks at the corners of the mouth ( angular cheilitis ) , and a sore throat .
Riboflavin deficiency can cause sores in the mouth ( mouth ulcers ) , cracked red lips , cracks at the corners of the mouth ( angular cheilitis ) , and a sore throat .