Symptoms, conditions and causes

Why do I have mouth sores?

Mouth sores (little ulcers) can be of two types: canker sores and cold sores.

If you have a canker sore (inside the lip or mouth) it is caused by a nutrient deficiency.

On the other hand, a cold sore (on the outside of the lip or around the mouth) comes from a viral infection.

Cause of canker sores: B12 and folate (B9) deficiency

A canker sore (white or yellow little ulcer inside the mouth) occurs in the body due to vitamin and nutritional deficiency, specifically of B12 and folate (B9). It can come from not enough intake of these nutrients from your food. Additionally, there are certain foods that deplete you of these vitamins: these are refined grains and carbs.


  • Take nutritional yeast (natural B12 and folate source)

  • Avoid consuming refined grains:

    • breads
    • pastas
    • crackers • cereal
    • biscuits
    • waffles
    • pancakes • etc.

  • If you have digestive problems you may have difficulties absorbing B12 and folate:

    • consume apple cider vinegar (1 to 2 teaspoons stirred into about a cup of water) before your meals

    • consume betaine hydrochloride before your meals

    • consume purified bile salts

    • do the Healthy Keto® diet

    • do intermittent fasting

Cause of cold sores: viral infection

A cold sore is a little ulcer, bump or sac that occurs in the body because of a viral infection called herpes simplex. A cold sore is usually activated by stress; it can kick in right away as a result of a stress event. If you have cold sores they are contagious for about 10 days.


  • Take lysine

  • Take natural vitamin C complex (not ascorbic acid)

  • Consume foods rich in vItamin C

  • Take vitamin D3

  • Take natural antibiotics

Last updated: Jun 21, 2023 14:10 PM