From: How I Treat Cobalamin (Vitamin B12) Deficiency, Ralph Carmel, Blood, September 2008
Note that as the amount of vitamin B12 injested goes up, the amount absorbed goes down. Wayyyy down. Only about 2% of a 500 microgram dose gets absorbed.
Individual variation is wide, both in normal persons and patients with malabsorption.
Many thanks for this. The rate of absorbtion depends on the fauna in the gut. The bacteria are largely responsible I understand for the bringing of food into the body via the intestines. If these are not functioning properly due to neuro-toxicity from most medications and such things as glyphosate residues then we have a problem.