| Iron deficiency is the most common nutrient deficiency throughout the world, including the United States. Although it has been known for over 125 years that symptomatic iron deficiency can exist in individuals despite normal levels of blood hemoglobin and red blood cell indices, current standards of medical practice frequently rely on measures of hemoglobin, hematocrit, mean corpuscular volume (MCV), and red blood cell distribution width (RDW) to screen for iron deficiency. The objective of this research is to determine how frequently iron deficient individuals are undiagnosed using hemoglobin, hematocrit, MCV, and RDW as indicators of iron status.;Data from eight National Health and Nutrition Examination Surveys (NHANES) studies (1976-2010) were included in the analysis. Males and females with data values for serum ferritin, hemoglobin, hematocrit, MCV, and RDW, not known to be pregnant or to have given birth within a year of data collection, were included in the analysis. Blood values from 56,000 individuals were stratified by study, gender, age and serum ferritin levels. Iron status was determined through the use of serum ferritin. Individuals were considered to be iron deficient and "missed" if adjusted serum ferritin was <21 ng/ml, but the levels of hemoglobin, hematocrit, MCV, and RDW were within normal ranges provided by the Centers for Disease Control and Prevention (CDC). Nonanemic iron deficiency (NAID) in various female age groups was missed 34% to 82% of the time. Younger males were missed for NAID 52% to 81% of the time, and males 40 years and older from 21% to 26% of the time. Therefore, screening for iron deficiency using hemoglobin, hematocrit, MCV and/or RDW fails to detect a significant portion of iron deficient individuals and can result both in delayed diagnosis and/or misdiagnosis that adversely affects the quality of life of the individual and incurs unnecessary medical costs. |
