METABOLIC STUDIES OF FOLIC ACID IN NON‐MALIGNANT DISEASES1

. The effect upon the serum folic acid activity (SFAA) of age, acute illness and chronic illness has been studied in 173 persons. Old, healthy subjects getting proper meals from institutional kitchens have normal SFAA, while those preparing their own food have low SFAA. The SFAA is normal in acute illness (thyreotoxicosis, fractures, after operations). In chronic inflammatory diseases (pulmonary tuberculosis, rheumatoid arthritis) low or subnormal SFAA is common. In rheumatoid arthritis patients the SFAA is lower the more active the disease and the higher the erythrocyte sedimentation rate. Serum iron and serum cholesterol are also low and correlated to both SFAA and sedimentation rate. The intestinal absorption of folic acid is normal in patients with rheumatoid arthritis, while the plasma clearance of folic acid is greatly increased. The high frequency of subnormal SFAA in this group may be explained by inadequate diet and/or increased turnover of folic acid in the plasma.