Vitamin A
Vitamin A, as retinol, is required for the formation and maintenance of the delicate surface membranes lining the mouth, as well as the throat, eyes, sinuses and digestive tract. Mucous membranes provide lubrication and are also an effective barrier against pathogenic microorganisms, contaminants and debris. Vitamin A deficiency leads to dryness of mucous membranes, especially of the mouth and eyes, which is also known as xeropthalmia. According to the National Institutes of Health, the recommended daily amounts of retinol range from 300 micrograms for children, to 900 micrograms for men, to 1,300 micrograms for lactating women. Good sources of retinol include pig, beef and fish livers, eggs, some cheeses and fortified dairy products.
Vitamin B-12 and Folic Acid
The body requires iron, vitamin B-12 and folic acid to produce healthy red blood cells within bone marrow. A deficiency of vitamin B-12 or folic acid, also known as vitamin B-9, results in immature red blood cells and a condition called pernicious anemia. The first symptoms of pernicious anemia are severe tiredness, headache and heart palpitations, although dryness of the mouth can result also, as cited in “Human Biochemistry and Disease.” If a dry mouth is the result of a B-12 or B-9 deficiency, then soreness and redness of the tongue should also be present. B-vitamins are often found together in foods of animal origin, such as meat, fish, poultry, eggs and milk.
Vitamin B-2
Vitamin B-2, or riboflavin, is primarily needed for the breakdown of fats, ketone bodies, carbohydrates and proteins. However, a riboflavin deficiency causes ariboflavinosis, which manifests as cracked lips, inflammation of the tongue and dryness or burning of the mouth, as cited in “Biochemical, Physiological and Molecular Aspects of Human Nutrition.” Burning mouth syndrome is characterized by a burning sensation and dryness in the mouth and on the tongue, and can be caused by deficiencies in vitamins B-2, B-9 and B-12.
