Vitamin B9 (
Folic acid) - also known as folate - is involved in the synthesis and repair of DNA which is especially important in the formation of new and growing cells.
In the liver,
folate is converted into
dihydrofolate and
tetrahydrofolate by the enzyme dihydrofolate reductase using reduced NADP, this is then methylated to give
5-methyl-tetrahydrofolate.
The main biochemical function of this compound is the transfer of this methyl group: methylation.
It is used as a coenzyme in the biosynthesis of thymidine which is a nucleoside (
subunit of DNA), and as a coenzyme in the synthesis of serine from glycine.
Folic acid works together with vitamin B12 (and iron) so lack of any of these can mask or compound the effects of deficiency. This may result in
macrocytic or megaloblastic anemia.
Much recent attention has been focussed on
neural tube defects in developing embryos; women should check their folate status before starting pregnancy.
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