Facial neuralgia and vitamin B12 deficiency
Vitamin B12 (cyanocobalamine) deficiency is known to cause a wide variety of neurological symptoms. It also seems to produce facial neuralgia, according to a report presented at the International Headache Congress in Philadelphia a week ago. Two physicians from Milwaukee described 17 patients who had facial pain that was not typical of trigeminal neuralgia because they had no trigger area and had numbness on the affected side. They all had vitamin B12 deficiency and they pain improved with injections of vitamin B12. In a previous post I mentioned another study that found an association between migraine headaches and high homocysteine levels, which can also be caused by vitamin B12 deficiency. Oral absorption of vitamin B12 supplements is often inadequate and a nasal spray (which is expensive) or an injection are the best ways to correct this deficiency.
What is the recomeneded treatment doses of the amount and frequency of the injected and nasal vit B 12 perscribed for migraine ? Is there any information on the success of this ?
I would like to know if there is any medline research mentioned on B12 and neuralgia. I would appreciate any scientific evidence shared. Thanks
The only way to find out if you are deficient is to do a blood test. However, a regular vitamin B12 level is not very accurate. The normal level is considered to be above 200. Some laboratories will not flag levels below 400 (which means that doctors are not likely to pay attention) , but will include a disclaimer saying that if the level is less than 400 neurological symptoms due to B12 deficiency may occur. Severe vitamin B12 deficiency has been reported in a patient with a level of over 700. In the vast majority of cases if the level is well above 400 you do not need to worry about this deficiency. However, if doubts remain two additional blood tests can establish with certainty if a deficiency is present. These tests are homocysteine and methylmalonic acid levels.
How do you know if you have a B12 deficiency?
Most people can absorb sufficient amounts of vitamin B12 from their diet and if the deficiency is mild an oral supplement can be sufficient. However, a serious deficiency is not likely to be corrected by an oral supplement or it will take a dangerously long time to correct it. Even if the deficiency is mild, but is causing symptoms, it is better to use reliable methods, such as an injection or a nasal spray.
While the active uptake pathway for B12 is unreliable, I read somewhere that about 1% of the oral dose is absorbed by passive diffusion. At that rate, a 1000 mcg oral dose will have an uptake of 10 mcg, which exceeds the RDA.