Folic acid deficiency has six major causes:
1) <I>inadequate diet</I> of fresh fruits and vegetables, the
consumption of over-processed foods in which the heat has destroyed
folate, or alcoholism that is often associated with a poor diet;
2) <I>inadequate absorption</I> due to malabsorption diseases such
as gluten-induced enteropathy, tropical sprue, or drugs such as
anticonvulsants, barbiturates, ethanol, cholestyramine, or azulfidine;
3) <I>inadequate use</I> by metabolic block due to folic acid antagonistic
drugs, enzyme deficiencies, vitamin B12 deficiency, alcohol, ascorbic
acid deficiency, and dietary amino acid excess of glycine and methionine;
4) <I>increased requirement</I> due to extra tissue demand by the
fetus or malignant tissue, infancy, increased metabolism, and
increased *hematopoiesis**;
5) <I>increased excretion</I> due to vitamin B12 deficiency, liver
disease, and kidney dialysis; and
6) <I>increased destruction</I> due to excess of antioxidant supplements.
