Take a diet rich in Vit
B12 which should include meat
and animal products, cheese, such as beef, liver, salmon, cod,
and eggs. Take B12 supplements and breakfast cereals fortified with vitamin B12. Finding the cause is important.
Other possibility is an acid reflux. Take Omeprazole empty stomach in morning and an antacid gel at bedtime. Refrain from smoking, alcohol, fuzzy drinks and spicy food. See if this helps.
Do discuss this with your doctor and get yourself examined. Take care!