Serum retinol levels are positively correlated with hemoglobin concentrations, independent of iron homeostasis: a population-based study

Micronutrient interactions give rise to complex issues that have an impact on preventive strategies when multiple micronutrient deficiencies coexist. The aim of this population-based study was to determine the prevalence of vitamins A and E and iron deficiencies among women 15 to 49 years of age in the northern Persian Gulf region. We hypothesized that serum retinol levels may show correlations with hemoglobin (Hb) concentrations, independent of iron status. A total of 1242 nonpregnant women of reproductive age were selected via a multistage stratified random cluster sampling technique. Serum ferritin and soluble transferrin receptor levels were measured using enzyme immunoassay techniques. Serum retinol (vitamin A) and α-tocopherol (vitamin E) were determined for 727 women by high-performance liquid chromatography. The prevalence of anemia (Hb <12 g/dL), iron deficiency (serum ferritin <15 μg/L), and iron deficiency anemia was 8.7%, 25.4%, and 4.6%, respectively. Vitamin A (<0.7 μmol/L) and vitamin E (<11.6 μmol/L) deficiencies were found in 1.2% and 5.9% of the studied population, respectively. Multiple regression analysis revealed that serum retinol levels exhibit a significant association with Hb concentrations after controlling for serum ferritin levels, anemia associated with chronic disease, and risk factors for anemia. Therefore, most nonpregnant women of reproductive age in the northern Persian Gulf were found to have adequate serum vitamin A and E levels. However, the status of anemia and iron deficiency anemia could be considered a mild public health problem in this region. On the basis of multivariate analyses, we conclude that low serum retinol levels may contribute to anemia, independent of iron homeostasis.