Hi!
It is difficult to comment without examining. The tongue could be red and cracked due to various reasons. It could be due to iron deficiency anemia, pernicious anemia and other B-vitamin deficiencies, aphthous ulcers, oral lichen planus, erythema multiform, pemphigus vulgaris, syphilis, yeast infection; exposure to irritants such as hot foods, or spices, tobacco, alcohol; allergy to toothpaste, mouthwash, breath fresheners, dyes in candy, dentures, food items, coloring agents, or blood pressure medications like ACE inhibitors. It could also be a mechanical irritation by a jagged tooth edge or a denture.
Please discuss this with your doctor. Maybe you should also have a dental checkup. Go over the list, something may strike you. If you have IBS or other gut problems or a poor diet then any deficiency could be the problem. You can take a multivitamin pill but it would be good to know the exact cause before starting any treatment. Hope this helps. Take care!
Have you looked up 'geographical tounge,? I have one of thes and foods, allergies, medications, can set me off for weeks even some tooth paste. Also could be a sigh of candida or thrush., just a couple of things to look uo, ibam not a doctoyr so can notbdiagnose butbliving m whole life with a geographical tounge hasc been rough so I have done some research on how tosooth. One this is to make csure your mouth is clean, taste bad and will hurt like hell but gargle with peroxide, brush/scrape your toungeobdaily and for a few days coat with minera or cocoanut oi... best shot is to look up and see if it fits your description and if it can helo... thanks Sandy