ABSTRACT
Folate is used as the generic descriptor for folic acid and related compounds exhibiting qualitatively the biological activity of folic acid. Folate contents of foods have been difficult to obtain. Over 150 forms of folate are known to exist in foods. In a vitamin B-12 deficiency, homocysteine is not remethylated and accumulates in the blood while folate accumulates as 5-methyltetrahydrofolate. Folate deficiency results in megaloblastic anemia which is identical to that caused by a deficiency of vitamin B-12. For evaluating folate nutritional status, the measurement of serum or plasma folate concentrations is most commonly performed. The deoxyuridine suppression test has been used to evaluate the functional status of certain folate-dependent and cobalamin-dependent enzyme reactions in short-term cultures of living cells. Folate normally is effectively reabsorbed by the proximal renal tubule, with little loss of intact folate. Folate nutritional status is usually evaluated through the measurement of folate concentrations in serum and erythrocytes.
