Decreased Iron Intake Parallels Rising Iron Deficiency Anemia and Related Mortality Rates in the US Population

Abstract

Background: Prevalence of iron deficiency anemia and its related mortality rate are on the rise in the United States and causes are unclear.

Objectives: The aim was to examine trends and causes of Fe deficiency anemia prevalence and Fe deficiency-related mortality rates in the total US population.

Methods: Changes in daily dietary Fe intake, serum iron concentration, hemoglobin, red cell distribution width (RDW), and mean corpuscular volume (MCV) obtained from the laboratory files of NHANES, Fe deficiency anemia-related mortality rates from the CDC, and iron concentrations of US food products from the USDA between 1999 and 2018 were analyzed.

Results: Of food items with revised concentrations in USDA Nutrient Database for Standard Reference [SR28 (2015)], 62.4% had lower Fe concentrations than in SR11 (1999). There was a 15.3% reduction in beef (relatively higher in heme iron) and a 21.5% increase in chicken meat consumption in the American diet between 1999 and 2018. Dietary iron intake decreased by ∼6.6% and ∼9.5% for male and female adults, respectively. Increases of prevalence of estimated anemia in the United States ranged from 10.5% to 106% depending on age and sex. Age-adjusted mortality rates with iron deficiency anemia as the underlying cause of death increased from ∼0.04 to ∼0.08 deaths per 100,000 people, whereas all other anemias as the underlying causes of death decreased by ≥25%. Mean RDW and serum folate concentrations increased, whereas hemoglobin, serum iron concentrations, and MCV, parameters traditionally associated with Fe deficiency anemia, decreased during this period.

Conclusions: Increased iron deficiency anemia and related mortality rates in the US population between 1999 and 2018 were likely related to the decline in dietary iron intake resulting from an Fe concentration decline in US food products and a shift in dietary patterns.

Keywords: anemia prevalence; iron deficiency anemia; iron deficiency–related mortality rates; iron in US food products; iron intake diet.

© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.