what is the best marker for B12 then? My last serum b12 was over 1500 pg/ml. I have since cut out methyl-B12 supplementation and just focus on meat/seafood for it.
I can't find the article or podcast that detailed better B12 testing and some of the logic behind it.. Sorry- I looked a few times
I do know that serum B12 only shows part of the picture. Whether it's high or low, it doesn't tell the why?
For example, bacteria in the small intestines can synthesize a type of B12 ( that shows up in serum markers ) that is unusable.
I also remember that B12 has an active form. The test to determine this is holo-TC....it represents the biologically active part of B12 that can actually be delivered to the cells and perform all of the functions of B12.
Just like anything else.. it's complicated and dependent on many other factors.
If you are relatively healthy and feel pretty good, you are probably right to just stop the supplementation and see what happens. Do the basics like eating whole foods diet, elimination diet like whole 30, test your blood sugar (fasting, post prandial) , and get good sleep. If you got other funky stuff going on ( like gut issues ) find a good functional medicine Doc that understands the nuances of B12 and methylation and get to the root of the problem.