Folic acid deficiency is the most common
hypovitaminosis of humans, primarily affecting the indigent population of the
world. Deficiency symptoms include poor growth, megaloblastic anemia, and other
blood disorders, as well as gastrointestinal tract disturbances.
The main consequence of a deficiency of
folate is a change in nuclear morphology. These nuclear alterations are termed
"megaloblastic" in reference to nucleated red blood cells in the bone marrow.
Morphological changes are also noticed in the stomach, small intestine, uterine
cervix, and vagina.
Several substances interfere with the
normal absorption of folate. Ethanol appears to affect folate metabolism as
well as its absorption. Antitumor agents interfere with folate utilization and
it has been suggested that anticonvulsants interfere with the absorption of
free folacin. Inadequate utilization of folates can be attributed to drugs that
interfere with folate metabolism. Some evidence suggests that oral
contraceptives alter folate metabolism, as megaloblastic changes occur to the
cervicovaginal epithelium. The megaloblastic anemia of scurvy has been
associated with defective utilization of folates.
Folic acid deficiency primarily occurs in
tissues with a high rate of cell proliferation. A high incidence of deficiency
of folacin in pregnant women has led the Food and Nutrition Board to recommend
that women ingest an additional 400 micrograms per day during pregnancy, on a
prescription basis. This supplement should only be given if the woman does not
have anemia. Folacin, by correcting the megaloblastic anemia, prevents the
diagnosis of pernicious anemia, which itself usually prevents conception. Fetal
damage has been associated with a folacin deficiency.
An individual with folic acid deficiency
is more susceptible to environmental carcinogens. A deficiency of folate
promotes the breakage of chromosomes at fragile sties. If the cell cannot
synthesize the constituents of DNA, deficiency might prohibit normal
differentiation and replication. Furthermore, inadequate folate levels may
reduce the production of white blood cells and hinder the body's ability to