RT Journal Article SR Electronic T1 Early detection of folic acid deficiency in elderly patients. JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 44 OP 46 DO 10.1136/jcp.31.1.44 VO 31 IS 1 A1 Raper, C G A1 Choudhury, M YR 1978 UL http://jcp.bmj.com/content/31/1/44.abstract AB Folic acid deficiency is very common in elderly patients who have a mean red cell volume greater than 94 fl. Eighteen out of 40 elderly patients with red cell macrocytosis who initially had normal red cell folate and serum B12 levels subsequently developed folic acid deficiency.