Diagnostic value of the serum folate assay

Abstract

SYNOPSISThe diagnostic value of the serum folate assay has been assessed in 90 patients, each of whom had a macrocytic anaemia and a low serum vitamin B12 level. Twenty-nine (32%) patients were found to have anaemia due primarily to folate deficiency. The cause of the low serum vitamin B12 levels is uncertain in the 22 (25%) patients with normal or borderline vitamin B12 absorption.The effect of folic acid therapy was studied in four of these patients, and in each case the serum vitamin B12 rose slowly to a normal level. pernicious anaemia 54 patients (41F, 13M); nutritional folate deficiency 18 patients (12F, 6M); idiopathic steatorrhoea 12 patients (7F, 5M); partial gastrectomy four patients (2F, 2M); anticonvulsant therapy one patient (M); unknown aetiology one patient (F).The intestinal absorption of 0 5 ,ug vitamin B12, labelled with 0-5 ,uC 57Co, was measured in every case. The absorbed radioactivity was counted in the serum (Harwood and Forshaw, 1967) in 66 patients, and in a 24-hour collection of urine (Schilling, 1953) (Spray, 1964) respectively. In our laboratory the normal range for the serum vitamin B12 level is 150 to 850 pg per ml and for the folate 2-1 to 10-0 ng per ml. 244 on 11 May 2018 by guest. Protected by copyright.

Changes in Erythroblast Morphology as an Index of Response to Cyanocobalamin in Patients with Megaloblastic Anaemia

“…Patients with PA usually have a normal or raised serum folate; a low serum level, evidencc of folate deficiency, is uncommon (Chanarin, 1969;Forshaw & Harwood, 1971). However, the altered handling of injected folic acid (Spray et a!, 1951; Chanarin et al, 1958) and the changes in amino-acid synthesis and excretion (Herbert et al, 1964;Zalusky & Herbert, 1961 ;Parry, 1969;Ellegaard & Esmann, 1973) indicate that vitamin B1 deficiency frequently results in a functional folate deficiency.…”