Chronic tongue lesions and cracks can stem from several causes, including chronic dry mouth, often a side effect of medications like isosorbide dinitrate, oral thrush, or inflammatory conditions. Since vitamin B-complex and vitamin A have not provided relief, it is crucial to consult an oral pathologist or dentist for a definitive diagnosis, which may involve a simple swab or biopsy. In the meantime, focus on staying well-hydrated, practising gentle oral hygiene, and avoiding spicy or acidic foods. Depending on the findings, targeted treatments such as antifungal mouthwashes or topical corticosteroid gels may be prescribed to promote healing.