Original Paper Received: September 19, 2013 Accepted after revision: December 11, 2013 Published online: February 26, 2014

Ann Nutr Metab 2013;63:323–330 DOI: 10.1159/000357955

Association between Nutrient Intake and Anemia in Brazilian Adolescents Ursula Viana Bagni a Edna Massae Yokoo b Gloria Valeria da Veiga c   

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Health Sciences College of Trairi, Federal University of Rio Grande do Norte, Santa Cruz, b Department of Epidemiology and Biostatistics of the Community Health Institute, Fluminense Federal University, Niterói, and c Department of Nutrition, Federal University of Rio de Janeiro, Ilha do Fundão, Rio de Janeiro, Brazil  

 

 

Abstract Aims: The association between the intake of iron, vitamins A and C and calcium and the prevalence of anemia and hemoglobin (Hb) levels was investigated in adolescents. Methods: A cross-sectional study was developed with 529 Brazilian students. Anemia was defined in terms of Hb concentration. Nutrient intake was assessed by a 3-day food record. The association between the prevalence of inadequate nutrient intake and anemia was estimated by the χ2 test, and that between nutrient intake and Hb by linear regression. Results: The prevalence of inadequate nutrient intake did not differ between nonanemic and anemic subjects. Anemic adolescents had a lower mean intake of iron than nonanemic adolescents. Among boys aged 11–13 years, the anemic subjects had lower vitamin C intake than those who were nonanemic (41.1 vs. 62.6 mg, p < 0.01), and among those aged 14–19 years, there was a tendency for a positive association between Hb and heme iron intake (β = 0.64, p = 0.06) and a negative association with calcium intake (β = –0.003, p = 0.02). In females, daily nutrient intake did not differ between anemic and nonanemic individuals. Conclusions: Heme iron and vitamin C are possible protective factors against anemia in boys. However, the lack of association between inadequate iron intake and anemia, especially in girls, suggests that other factors beyond diet could explain anemia in this age range.

Introduction

Dietary habits during adolescence are marked by inappropriate practices, such as skipping breakfast, substituting snacks for lunch and dinner, the consumption of fast foods and drinks with excessive amounts of sugar and fat, the reduced intake of milk, fruits and vegetables and adherence to diets ruled by fashion and dictated by the media, friends and family [1, 2]. In Brazil, adolescents have low consumption of beans, fruits, dark green and orange vegetables and high rates of consumption of sandwiches, cookies, soft drinks and snacks [2, 3]. The maintenance of such eating habits in adolescence not only increases the risk of developing chronic diseases, such as obesity and related metabolic disorders [4], but also increases the risk for iron deficiency anemia [5–7] due to the insufficient intake of iron-rich foods and iron absorption facilitators, such as vitamin C, as well as the intake of foods rich in calcium (ice cream, milkshakes), tannins (sodas, mate, teas, coffee), oxalate (chocolate, coffee) and phytates (cereals), which impair the absorption of iron when consumed at the same meal. Although insufficient intake of iron is not the only cause of anemia, iron deficiency anemia is the major concern from the public health point of view due to its high prevalence in many countries [8, 9]. An association between eating habits and anemia in adolescents has been observed in some countries, and the

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Ursula Viana Bagni, PhD Health Sciences College of Trairi Federal University of Rio Grande do Norte Rua Trairi, s/n, Centro – Santa Cruz, Rio Grande do Norte, CEP 59200-000 (Brazil) E-Mail ursulaviana @ gmail.com

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Key Words Adolescents · Anemia · Nutrient intake · Iron

Methods A probabilistic sample of adolescents aged 11–19 years attending public schools in the city of Niterói, located in the metropolitan area of Rio de Janeiro, southeastern Brazil, was assessed in a crosssectional study conducted between May 2008 and April 2009. The students were enrolled in 13 out of 34 public state schools that participated in a larger research project, the main objective of

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Ann Nutr Metab 2013;63:323–330 DOI: 10.1159/000357955

which was to assess the evolution of overweight and obesity in teenagers by comparing two cross-sectional studies carried out between 2003 and 2008/2009. In Brazil, public schools are usually attended by students of a lower socioeconomic status. The sample size was estimated to be 780 students, distributed among 34 classes (with approximately 23 students each), taking into account the 30% nonresponse rate observed in the pilot study. With this sampling size, it would be possible to estimate a 35% prevalence of anemia [15] at a 95% confidence interval (CI) with 5% precision when considering the cluster sampling design in one selection stage (random classes). Participation was voluntary, and only students with regular attendance and who had consent forms signed by their parents were allowed to participate. Students were excluded from the study if they were physically impaired and unable to take part in the anthropometric assessment, pregnant or reported a history of diseases leading to anemia (not caused by iron deficiency), iron accumulation diseases, capillary fragility and/or coagulation abnormality in an interview administered prior to the blood test. Blood Hb concentration was assessed using a portable β-hemoglobinometer (HemoCue®). Adolescents between 10 and 11 years old with Hb

Association between nutrient intake and anemia in Brazilian adolescents.

The association between the intake of iron, vitamins A and C and calcium and the prevalence of anemia and hemoglobin (Hb) levels was investigated in a...
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