Fredd,
Could you provide a perspective on how or if B12 gets through the blood brain barrier. I believe you have said that many people with MS, Alzheimers, etc have low cobalamin levels in their brains. Aren't B12 molecules too large to get through the blood brain barrier?
Hi Idie,
So far I have no idea how b12 actually is supposed to get into the CSF. It is assumed that there is an active system. Not too many years ago everybody assumed that b12 had too large a molecule to get through the skin. Now there are patches, nasal gels, sublingual tablets etc that all clearly can demonstrate at least a degree of diffusion through the skin. In the mouth there is a clear concentration-time factor to that diffusion.
In the literature all the research is based on only an assumption of ONLY distribution by the active distribution system. Nobody talks about the b12 diffusion to the tissues that benefits all of us taking more than a few micrograms a day.
The Japanese 50mg dose research is all based on an assumption of high gradiant diffusion push into the CSF. They demonstrated that direct 2.5mg injection into the CSF has a similar effect to 50mg/day except that it lasts for 3 months to 4 years with a single such injection instead of daily doses lasting one day.
So taking advantage of that as demonstrated by the Japanese studies, I and others have found that 4x7.5mg and 3x10mg and 2.15mg are all about as effective for at least some people. Further I have done a trials up to 180mg/day (3x 60mg), and at leat with the quality of mb12 I have (3 star) it makes no real difference over 3x10mg.
I have to assume that the threshold for diffusion through the BBB requires a serum level of cobalamin at the approximate estimated level of 200,000pg/ml, or 200ng/ml, which if maintained 24/7 approximate the effects of a direct mb12 injection into the CSF, which is a much more invasive procedure.
I hope that I have answered your question to your satisfaction. It's just that there is no good answer at the moment.