Low clinical utility of folate determinations in primary care setting

Fortification of cereal products with folic acid is not mandatory in Israel, yet folate deficiency remains rare and is usually associated with poor diet, malabsorption, alcoholism, or use of certain drugs. A retrospective review of all folate level determinations performed between January 2004 and January 2007 in the central district of Clalit Health Services in Israel revealed that only 4.3% of the 43,176 tests ordered were below the norm (5.6 nmol/L).

To determine parameters that identify folate-deficient patients without known risk factors and to establish principles that aid the physician in deciding when to order folate determinations.

Study population included 152 patients from 13 large primary care clinics with folate deficiency but without known risk factors for folate deficiency (37 with anemia). They were matched with 556 controls (141 with anemia).The medical records were reviewed for the indication of the test and treatment that followed the results.

Hematologic indices, vitamin B12, ferritin, and transferrin saturation levels were similar in the study and control groups. Subgroup comparisons based on anemia status showed similar results. The clinical indications for folate determinations were similar in the folate-deficient patients and the control group. Only 68 of 152 patients (44.7%) were prescribed a folate supplement.

Neither laboratory parameters nor clinical findings in patients' charts were capable of distinguishing folate-deficient patients from controls. It seems that folate determinations in patients without known risk factors for folate deficiency are of little clinical significance.