Association of Higher Intakes of Dietary Zinc with Higher Ferritin or Hemoglobin: a Cross-sectional Study from NHANES (2017-2020).

Abstract

Zinc is an essential trace element that plays a critical role in numerous physiological processes, including immune function, cell growth, and particularly iron metabolism. This study aimed to explore the association between dietary zinc intake and key biomarkers of iron status, specifically serum ferritin and hemoglobin levels, in a representative sample of the US population. A cross-sectional analysis was conducted using data from the 2017-2020 National Health and Nutrition Examination Survey (NHANES), which included 15,560 participants. Dietary zinc intake was assessed through 24-h dietary recall, and serum ferritin and hemoglobin levels were measured through laboratory tests. Participants were grouped into quartiles based on their zinc intake. Multivariable linear regression models were applied to evaluate the relationship between dietary zinc intake and ferritin and hemoglobin levels, adjusting for potential confounders such as age, sex, body mass index (BMI), waist circumference, energy intake, macronutrients, and micronutrients. These adjustments ensured a more accurate analysis of the associations between zinc intake and iron markers. Our findings demonstrate that higher dietary zinc intake is significantly associated with elevated serum ferritin (B = 6.17, p = 0.027) and hemoglobin (B = 0.048, p = 0.019) levels, independent of other factors. Participants in the highest zinc intake quartile also showed higher hematocrit and mean corpuscular volume (MCV) levels compared to those in the lowest quartile. These results suggest that adequate dietary zinc intake may play a crucial role in improving iron status and reducing the risk of iron-deficiency anemia, particularly in populations at risk. Future research is necessary to further elucidate the mechanisms behind this relationship and to inform public health nutritional guidelines.