Multiple micronutrients, including zinc, selenium and iron, are positively associated with anemia in New Zealand aged care residents

Abstract

Anemia is a significant comorbidity for older adults not fully attributable to iron deficiency. Low‐grade inflammation and other micronutrient deficiencies also contribute. This cross‐sectional study examined the relationships between nutrient and non‐nutrient factors with hemoglobin and anemia in 285 residents (>65 years) of 16 New Zealand aged‐care facilities. Blood samples were analyzed for hemoglobin, ferritin, sTfR, hepcidin, zinc, selenium, and interleukin‐6 (IL‐6), (with ferritin, sTfR, zinc and selenium adjusted for inflammation). Linear regression models examined the relationships between micronutrient biomarkers (iron, zinc, selenium, vitamin B‐12 and D), age, sex, and health factors with hemoglobin. Thirty‐two percent of participants exhibited anemia, although <2% had either depleted iron stores or iron deficiency. Plasma zinc and selenium deficiencies were present in 72% and 38% of participants, respectively. Plasma zinc and total body iron (TBI) were positively associated (p < 0.05) with hemoglobin, while gastric acid suppressing medications, hepcidin, and interleukin‐6 were inversely associated. These relationships were maintained after the application of anemia cut‐offs. These findings emphasize the importance of considering multiple micronutrient deficiencies as risk factors for anemia.