It is common to have fat-soluble vitamin deficiencies with celiac so my GI doctor thinks it is probably the cause. My nutritionist recommends 10,000 IU of Vitamin A to patients with a deficiency. At the vitamin store, there was only one 10,000 IU Vitamin A bottles so I bought that one. The rest were 5,000 IU.
Remember that one can have gluten sensitivity without having celiac disease.
I do not know if you red my initial post about Vitamin A deficiency, but Vitamin A is more linked to the issues happening with our lips.