Day-to-day variation in serum ferritin concentration in healthy subjects.
We report our observations on day-to-day variation in serum ferritin, serum iron, total iron-binding capacity, and percent saturation of binding proteins with iron in 13 ostensibly healthy subjects during five weeks. The average intrasubject coefficients of variation were 14.5, 28.5, 4.8, and 28.0%, respectively. Precision studies on control samples showed greater within-assay and between-assay analytical variation for serum ferritin than for serum iron or total iron-binding capacity. Evidently, serum ferritin varies less in a given individual from day to day than do serum iron and percent iron saturation. Thus, a single measurement of serum ferritin may be a more reliable index of iron stores than an isolated determination of either serum iron or percent iron saturation.
D000328:Adult; D002352:Carrier Proteins / Q000097:blood; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D007501:Iron / Q000097:blood; D033862:Iron-Binding Proteins; D008297:Male; D013997:Time Factors; D033863:Transferrin-Binding Proteins
D002352:Carrier Proteins; D033862:Iron-Binding Proteins; D033863:Transferrin-Binding Proteins; D005293:Ferritins; D007501:Iron