I couldn't find the answer to this question.
I sent an enquiry to The Weston Price Foundation.
This is their answer:
"per Sally Fallon
Whatever is the kind of B12 they test for, that should be near 1000.
That means that the optimal level of B12 in blood should be near 1000 and HoloTC also around 1000?
Current TDL lab ranges:
Active B12 pmol/L 25.1 - 165.0
Red cell folate nmol/L 285.4 - 1474.7
These are the new ranges from March 2015
Are there any studies showing side effects from taking too much of B12.?
I have Hashimoto, hypothyroidism and recently said hello to Pernicious Anemia.
I know that they are all related. Has anybody achieved an optimal health in a similar situation using a functional medicine practitioner and self knowledge?
Thanks for your feedback.