Q. I was excited to read about canker sores in your column. They are also called aphthous ulcers.
I have suffered for many years with extremely painful mouth ulcers. I read a magazine article that mentioned a study done at Ben-Gurion University in Israel. They found that patients given 1000 micrograms (mcg) of vitamin B12 for a six-month period experienced a substantial decrease in break-outs or even a complete cure.
I have been on this regimen for six months to date, and if I experience any sore, it lasts for only one day, then disappears completely. I recommend that people who have recurrent canker sores check with the physician first, and then consider 1000 mcg of vitamin B12. It has made a major difference in my life. No more suffering, no more pain.

A. We tracked down the study you read about. It was published in the Journal of the American Board of Family Medicine (Jan-Feb., 2009). The investigators used a sublingual (under the tongue) form of vitamin B12. They concluded, “Vitamin B(12) treatment, which is simple, inexpensive, and low-risk, seems to be effective for patients suffering from RAS [recurrent aphthous stomatitis, or canker sores], regardless of the serum vitamin B(12) level.”

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  1. EMartin

    Lysine, B12, and Choline/Inositol (or Lecithin) all work to reduce canker sores. I take all three and I haven’t had one in over a year.

  2. MLombardi

    I too seem to get mouth sores when I take b vitamins, what does that mean?

  3. HC

    Well that’s interesting. it’s disappointing to hear that dark chocolate can cause cankers; I need the dark chocolate for it’s benefits. It never caused me a problem until recently.
    My cankers have been coming and coming without apparent rhyme or reason, so I decided to do some research and found these discussions fascinating. Several different items could apply to my situation.
    I am always battling iron deficiency; apparently I don’t absorb iron well and it’s been a lifelong struggle along with obesity. I take multivitamins, probiotics, iron, calcium, MSM crystals, L-carnitine, extra D, some yogurt and a spray of liquid B-12 sublingually now and then. I have trouble absorbing iron, am osteopenic, have osteoarthritis, sometimes have trouble sleeping, so you see a combination of self-help recommended by various sources and approved by my doctors.
    I suspect that changing from Tom’s of Maine to Kiss My Face toothpaste caused my latest outbreak. I just ate a 4oz carton of vanilla yogurt and found it very soothing to my mouth. Here’s hoping changing back to my old toothpaste and continuing with the Activia cures my cankers.

  4. HC

    Now I know why Lysine is sold in health food stores; I’ve heard of this before and will give it a try.

  5. HM

    That’s ironic to me. When I would take vitamin B-12 and folic acid supplements, I would GET canker sores, that didn’t go away until I stopped taking both. Both are acids; I wonder if acidity was the problem?

  6. HC

    My problem seems to have worsened when I changed to a new brand of toothpaste. My brother in law was a dentist, and he said we would all be better off brushing with a solution of baking soda and water, because of the sweeteners in toothpaste. Thanks for the tip; I’ll go back to using Tom’s of Maine.

  7. Alvin J. S.

    Analgesics, anti-inflammatory agents, antiseptics, steroids and other medication are helpful in curing white blisters. If you are often plagued with canker sores or white blisters, you should consult a doctor and he/she will advise you accordingly. If you want to get rid of white blisters, you could also include vitamin B12 supplements in your diet, irrespective of a deficiency. White blisters can be prevented by taking a proper well-balanced diet rich in iron, zinc and vitamins. Intake of yogurt regularly would help to avoid the breakout of various types of oral ulcers.

  8. len811

    Niacinamide has always worked for me over many years, and also for my three (now grown) children. 200 mg 4 or so times a day for a few days. The sooner one starts, the faster the sore is gone. However, pain is usually gone after first or second dose. Good idea to take couple of extra B-Complex or “Stress” type B formula as well since, so I have read, much extra of one B might cause loss of others.
    A friend has had good results with lysine, but when a recent sore did not respond she found Niacinamide did the trick for her.

  9. HRF

    My very frequent mouth sores are almost non-existent now that I use a small methylcobalamin patch behind the ear twice weekly. If your stomach doesn’t produce sufficient HCl you may find that It also doesn’t make enough intrinsic factor to absorb dietary B12, thus, B12 deficiency (best found by urine test) may often cause canker sores.
    The tiniest amount of good quality dark chocolate I ate used to lead to one of these small ulcers. Now I can have a piece or 2 without all that suffering. Make sure that any patch uses the above B12 form, not cyanocobalamin which is cheaper and not the type best suited to human digestion (there is also a small amount of folic acid in the patch).

  10. A

    I have noticed that if I get a canker sore that if I brush directly on it, it hurts like the dickens while brushing but then feels better afterword and disappears significantly faster.

  11. Jason

    I had no idea that vitamin B-12 helped get rid of canker sores. I have been plagued with them for many years and have tried all kinds of remedies. I know there are some toothpastes that can help prevent them as well.

  12. KAE

    Many years ago, my uncle told my dad to put vick’s vapor rub on canker sores for pain relief and to lessen the amount of time that needed to for them to heal. Have been using it ever since with very good results. My uncle reviewed and approved applications for chemical patents and the US Patent office in DC.

  13. PT

    What forms of B-12 are there in dietary form that would satisfy taking 1000mcg daily?

  14. PW

    I used get canker sores all the time, sometimes 2 or 3 at a time. I noticed that brushing my teeth with toothpaste that contains baking soda and peroxide along with avoiding eating anything with sharp corners (chips, cracker) diminished the occurrence substantially. It’s been at least 2 years since getting one.

  15. AD

    What is a good way to easy the pain? It radiates to my chin, jaw and even ear.

  16. GB

    My daughter gets terrible canker sores in her mouth. So this is exciting information. Do you know if the B-12 vitamin purchased should be one that goes under the tongue, or can it be any type of B-12? Thanks.

  17. BRS

    I think I may have gotten the virus that causes cold sores from a dentist’s office. I began to notice I would get a cold sore after a prolonged dental procedure such as a crown. I did not have cold sores during most of my life when I went to the same dentist (about 40 years and he did several crowns), I do not have much anxiety about going to the dentist because I had a very nice one for so many years, and I do not have much stress in my life.
    At any rate, what do you suggest for dealing with a cold sore? I’ve used most OTC cold sore meds to no avail. In fact the most expensive OTC med prolonged the duration of the sore. Also I have not noticed much help from L Lysine. I take Vitamin B12 in a multi-vitamin. Should I take more of that? I am not a vegetarian; I get plenty of meat to eat. Is there an “old fashioned” treatment or this irksome virus? Thanks BRS

  18. kjm

    My body does not absorb oral Vit B-12, I take 1000 mcgm by injection monthly. I have had two stress-induced nasal cold sores recently, which I’ve not had for several years. Don’t know if that is related to canker sores.

  19. m

    Dr Oz just recently said to mix hydrogen peroxide half and half with water and apply to sore in mouth with a q-tip. After using all of the above I found this to be terrific, also so far, 3 weeks no return of issue.

  20. Toni T.

    When a tingling sensation starts in your mouth, immediately start taking (2) 500 mg L-Lysine tablets on the first day of a typical flare-up.
    Take one tablet a day after the first dose until the mouth sores are gone. These tablets can be found over the counter in many places. Over time the frequency of the flare-outs will diminish. Lysine is an indispensable amino acid needed for the health of the skin and lips. Lysine also promotes immune function.
    Many times, stress brings on these painful mouth ulcers. A virus is responsible for the outbreak.

  21. Brenda G

    The dental office I work informed us in a staff meeting that we should suggest patients with this problem stop using all toothpaste containing sodium lauryl sulfate. This is the ingredient that causes toothpaste to foam and that is a main cause in ulcers. When I stopped using toothpaste with it my ulcers of weekly occurrence stopped.

  22. Amy M

    I got canker sores off and on for most of my life. Haven’t had a recurrence since being on B12.
    I believe that it’s best to take 1000 mcg B12 lozenges and let them dissolve sublingually for the best absorption of the vitamin.

  23. Jennifer E.

    I am very excited to read the information about vitamin B12 and canker sores. I have suffered with them since I was about 5 (I’m now 40). I am wondering if there is any danger in taking too much vitamin B12. I noticed on my daily vitamins that the RDA for this vitamin is 6mcg per day and the study suggest 1000 mcg per day. Thanks so much!

  24. Eliza

    I used to get canker sores easily, from citrus and some other fruits. Years ago I found out my vitamin B12 levels were low (long-time vegetarian) and started taking B12 supplements. I’ve noticed that I rarely get canker sores anymore, but I had no idea why. This explains it – thank you.

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