Assessment of iron and zinc intake and related biochemical parameters in an adult Mediterranean population from southern Spain: influence of lifestyle factors.

This study assessed factors influencing iron and zinc intake and associated biochemical parameters in an adult population from southern Spain to identify patterns of intake and groups at risk for deficiency. A cross-sectional survey was done in Andalusia (southern Spain) to study nutrient intakes in a random sample of 3421 subjects (1747 men, 1674 women, age between 25 and 60 years). Blood samples were obtained for biochemical assays in a random subsample of 354 subjects (170 men, 184 women). Food consumption was assessed by 48-h recall. In blood samples, we measured red blood cells, haemoglobin (Hb), haematocrit, total iron binding capacity (TIBC) and plasma concentration of Fe and Zn. Information about educational level, smoking habit, alcohol consumption and physical exercise was collected with a structured questionnaire. Intakes were below two thirds of the recommended dietary allowances (RDA) in 22.45% of the sample for Fe and in 56.45% for Zn. Iron deficiency [two or more abnormal values for plasma Fe, TIBC, transferrin saturation and mean cell volume (MCV)] was found in 12.7% of the sample, and iron-deficient anaemia (low values for Hb, MCV, mean cell Hb and mean corpuscular Hb concentration) was found in 2.1%. In smokers, plasma levels of Fe were higher, and MCV was lower than in nonsmokers. Plasma Zn concentrations were below the reference value in 17.8% of the persons. Age and body mass index correlated inversely with plasma Zn (P<.01). Gender, age, obesity, smoking, alcohol consumption and physical activity were associated with differences in nutrient intakes. Logistic regression analysis showed that female gender and older age were associated with the risk of low intakes of Fe and Zn.