B-12 does have some role in the rate of production of RBCs, but it is primarily responsible for the maturation of the cells. Without
sufficient B-12 the blood cells are fragile and have poor oxygen carrying capacity. Injectible B-12 is primarily stored in the liver, and once the saturation level has been reached the rest is just excreted. I've tried the 10,000 I.U. injections bi-weekly, and really did not get much results from it - but then again, I was on
a whole bunch of other products such as oxymetholone.