Hey, As I see in image it's not an ulcer it's white patch isn't it . It doesn't look any major issue try keeping your oral hygiene, drinks lot of citrus juice, clean your tongue. I don't think it's because off crown as it's patch n not ulcer.. Still consider seeing a dentist. Good luck

Apply g 32 gum paint over that area 2 to 3 times a day and rinse after 15 minutes and then see the result

This white patch which is seen in the picture does not seem to be due to any vitamin deficiency so your present medicines will not help. It needs to be thoroughly examined. Kindly visit an Oral Medicine specialist. Oral Medicine is a speciality which deals with diseases of mouth like white patches, ulcers, pre cancers and many more. You can get it checked at any dental college or a private clinic. Regards

Hello,one with vitamin b12 deficiency with have reddish tongue ,this could be leukoplakia,oral thrush or oral lichen planus, leukoplakia causes cells in the mouth to grow excessively. That, in turn, leads to the formation of white patches inside the mouth, including on the tongue. Leukoplakia can develop when the tongue has been irritated, and it is often found in people who use tobacco products.