Why are vitamin B12 and folic acid important for production of erythocytes?

Question

Why are vitamin B12 and folic acid important for production of erythocytes?

Answer 1

The short answer is that folate (B9) and B12 are both necessary for the production of DNA building blocks, notably thymine (but other bases as well).  B3 and B6 are also involved in this pathway, but you absolutely need B9 (for the formation of something called methyl tetrahydrofolate, or CH3-THF) and B12 (which is the only acceptor for the CH3 portion of that molecule).  Eventually this pathway forms something called dTMP (2'-deoxythymidine-5'-phosphate) and that is what eventually winds up in DNA.  (This is horribly oversimplified; if you want to look at the whole pathway, it's here (from my very own biochem professor!):  http://www.hscbklyn.edu/SUNY/Biochem/ALC...

But that may be more than you wanted to know.  ;-)

The reason this is so extremely important in erythropoesis is just that you are constantly turning over red blood cells and needing to make more--cell division is absolutely necessary.  It's not that B9 and B12 are not important for other things as well, but you will generally become anemic faster than you will develop other problems.