Hi Jpurneyman, The ratios come through titration. in one section theres talk of 1mg of methyl b12 being able to bind as much as 10mcg of B12. I have no idea what you are talking about. Please quote what you think you read. I need 10mg of methyl B12 (from a 5 star brand !) to get an effective dosage of 100mcg 1mg = 1000mcg 10mg of ENZT held for two hours can put 3000mcg into your blood serum causing a temporary serum level of 300,000 to 600,000 pg/ml Within 24 hours 99% will be excreted via the kidneys. About 25mcg could bind to with TC2 making HTC2, a few micrograms. However, 100mcg in circulation will also do the same thing except not have the CNS penetration.