Recurrent aphthous ulceration: an epidemiological study of etiological factors, treatment and differential diagnosis

Abstract: BACKGROUND: Recurrent aphthous ulcerations are common benign ulcerated lesions on the mouth, whose etiology is poorly understood, with controversial treatment and difficult to control in clinical practice. OBJECTIVE: To evaluate the cases of recurrent aphthous ulcerations with a focus on treatment, diagnosis and etiology. METHODS: This is a retrospective study of the cases of the Oral Diagnosis service of the Rio Grande do Norte Federal University in Natal/RN. Data such as sex, age, race, location, smoking habits, types of treatment, relapsing episodes, laboratory test results and clinical characteristics were collected. The associations between the variables were analyzed using the Pearson Chi-square test (p <0.05). RESULTS: A total of 4895 patients were seen in the service over a period of 11 years. Of these, 161 (3.3%) had complaints of oral aphthous ulcerations, of which 76 (47.2%) were diagnosed as suffering from recurrent aphthous ulcerations and 68 (42.2%) with clinical information necessary for evaluation. The tongue was the most affected anatomical region, with 27 individuals (39.7%), followed by the buccal mucosa, with 22 cases (32.3%). STUDY LIMITATIONS: Retrospective study with data from medical records. CONCLUSION: Dental surgeons, dermatologists and otorhinolaryngologists are the main responsible for the first contact with patients with this disease and should be attentive to the clinical aspects and treat each patient in an individualized way, since the therapy is palliative, its diagnosis is by exclusion and its etiology is unknown.

Efecto del zinc aminoquelado y el sulfato de zinc en la incidencia de la infección respiratoria y la diarrea en niños preescolares de centros infantiles / Effect of zinc amino acid chelate and zinc sulfate in the incidence of respiratory infection and diarrhea among preschool children in child daycare centers

Introducción. El déficit de zinc es común en niños de poblaciones en desarrollo. La deficiencia de zinc altera el sistema inmunológico y la resistencia a las infecciones. Objetivo. Evaluar el efecto de dos compuestos de zinc en la prevención de la infección respiratoria y la diarrea agudas. Materiales y métodos. Se llevó a cabo un ensayo comunitario triple ciego en 301 niños entre dos y cinco años de edad de centros infantiles de Medellín. Fueron seis conglomerados distribuidos aleatoriamente en tres grupos de intervención que recibieron zinc aminoquelado, sulfato de zinc y placebo durante cinco días de la semana a lo largo de 16 semanas. Se evaluaron diariamente los síntomas de infección respiratoria, diarrea aguda y efectos secundarios. Resultados. La incidencia de la infección respiratoria fue menor con el zinc aminoquelado (1,42 por 1.000 días-niño) comparado con el sulfato de zinc (1,57 por 1.000 días-niño) (RR=0,90, IC 95% : 0,382 a 2,153 , p=0,999) y con el placebo (3,3 por 1.000 días-niño) ( RR=0,43, IC 95% : 0,196 a 0,950 , p=0,049). La incidencia de diarrea aguda con el zinc aminoquelado (0,15 por 1.000 días-niño) fue menor que con el sulfato de zinc (1,18 0,78 por 1.000 días-niño) (RR=0,20, IC 95% : 0,0043 a 1,662, p=0,361) y que la del grupo placebo (0,49 por 1.000 días-niño) (RR=0,32, IC 95% : 0,006 a 3,990 , p=0,346). Conclusiones. El zinc aminoquelado tuvo mejor efecto en la disminución de la incidencia de la infección respiratoria y la diarrea agudas en niños preescolares comparado con los otros grupos de estudio.

Introduction: Zinc deficiency is common in children among populations in developing areas. Zinc deficiency alters the immune system and the resistance to infections. Objective: To evaluate the effect of two zinc compounds in the prevention of acute respiratory infection and acute diarrhea. Materials and methods: Randomized triple-blind community trial with 301 children between 2-5 years of age from six child daycare centers in Medellin, Colombia. Children were distributed in three groups receiving zinc amino acid chelate, zinc sulfate and placebo five days a week for 16 weeks. Daily symptoms of respiratory infection, acute diarrhea and side effects were evaluated. Results: The incidence of respiratory infection was lower with zinc amino acid chelate (1.42 per 1,000 child-days) compared with placebo (3.3 per 1,000 child-days) (RR=0.43, 95% CI: 0.196 to 0.950, p=0.049) and with zinc sulfate (1.57 per 1,000 child-days) (RR=0.90, 95% CI 0.382 to 2.153, p=0.999). The incidence of acute diarrhea with zinc amino acid chelate (0.15 per 1,000 child-days) was lower than with placebo (0.49 per 1,000 child-days) (RR=0.32, 95% CI 0.006 to 3.990, p=0.346) and with zinc sulfate (0.78 per 1,000 child-days) (RR=0.20, 95% CI: 0.0043 to 1.662, p=0.361). Conclusions: Zinc amino acid chelate had a better effect in reducing the incidence of acute respiratory infection and acute diarrhea in preschool children when compared with the other groups.

Deficiência de micronutrientes e crescimento linear: revisão sistemática de estudos observacionais / Micronutrient deficiencies and linear growth: a systematic review of observational studies

O objetivo do artigo é avaliar a associação das deficiências de ferro, vitamina A e zinco com o déficit de crescimento linear. Revisão sistemática nas bases de dados eletrônicas PubMed, LILACS e SciELO. Foram selecionados artigos publicados entre janeiro de 1995 e março de 2010, considerando os descritores: (growth OR nutritional status) AND (child, preschool OR infant) AND (zinc AND iron AND vitamin A) OR (zinc AND iron) OR (zinc AND vitamin A) OR (iron AND vitamin A). Foram revisados 14 estudos de delineamento observacional. Dos estudos tipo coorte (dois), um indicou associação estatística entre o estado nutricional de ferro e o déficit de estatura; o outro apontou associação estatística entre as concentrações de ferritina sérica e o ganho de estatura. Dez estudos transversais investigaram a associação estatística entre as deficiências de micronutrientes e o déficit de estatura, resultando três deles na associação para o ferro, dois para a vitamina A e nenhum para o zinco. O esclarecimento sobre a associação entre o déficit de estatura e as deficiências de ferro, vitamina A e zinco dificulta-se por fatores de caráter biológico e relacionados à magnitude das deficiências, o que sugere a importância da padronização metodológica dos estudos.

This article seeks to evaluate the association of iron, vitamin A and zinc deficiencies with linear growth retardation. A systematic review of electronic databases in PubMed, LILACS and SciELO was conducted. Scientific papers published between January 1995 and March 2010 were selected, inserting the key words: (growth OR nutritional status) AND (child, preschool OR infant) AND (zinc AND iron AND vitamin A) OR (zinc AND iron) OR (zinc AND vitamin A) OR (iron AND vitamin A). Fourteen observational design studies were reviewed. In the cohort studies (two), one indicated a statistical association between iron levels and stunting; and the other revealed a statistical association between serum ferritin concentrations and an increase in height. Ten cross-sectional studies investigated the statistical association between micronutrient deficiencies and stunting, three of which resulted in an association with iron, two with vitamin A and none with zinc. Elucidation of the association between stunting and iron, vitamin A and zinc deficiencies involves difficulties of a biological nature and also related to the magnitude of these deficiencies, indicating the importance of a methodological standardization of the studies.

Crescimento e deficiências de micronutrientes: perfil das crianças assistidas no núcleo de creches do governo da Paraíba, Brasil / Growth and micronutrient deficiencies: profile of children attendied at the day care center for the government of Paraiba, Brazil

O objetivo deste artigo é avaliar o perfil de crescimento das crianças assistidas no Núcleo de Creches do Governo da Paraíba e a contribuição relativa das deficiências de vitamina A, ferro e zinco. Estudo transversal em 240 crianças pré-escolares. Foram consideradas as categorias de diagnóstico nutricional: déficit ponderal, déficit de estatura e sobrepeso. As concentrações séricas de retinol, zinco e de hemoglobina foram determinadas para avaliar a deficiência de vitamina A (< 0,70 µmol/L), deficiência de zinco (< 65 Μmol/L) e anemia (< 110 g/L), respectivamente. A prevalência de déficit de estatura foi de 5,8%, a de sobrepeso de 3,8%, e a de déficit de peso de 0,4%. A média de Escore-Z para o índice P/E foi menor e estatisticamente significante quando a mãe da criança foi diagnosticada com baixa estatura ou com baixo peso e nas crianças de 12-36 meses de idade. Para o índice E/I, a média de Escore-Z foi menor e estatisticamente significante quando a criança nasceu com baixo peso e quando a mãe da criança apresentou baixa estatura. Crianças de 12-36 meses e sem o beneficio do Programa Bolsa Família tiveram média de hemoglobina menor. Verificou-se ausência de associação significante entre as deficiências de vitamina A, ferro e zinco e os índices antropométricos estudados.

This article seeks to evaluate the growth of children attending public day care centers of the Government of the State of Paraiba and the relative significance of vitamin A, iron and zinc deficiencies. It involved a cross-sectional study of 240 preschool children. The following categories of nutritional status were considered: underweight (W/H < -2 z-scores), stunting (H/A < -2 z-scores) and overweight (W/H > +2 z-scores). Serum concentrations of retinol, zinc and hemoglobin were established to assess vitamin A deficiency (< 0.70 mmol/L), zinc deficiency (< 65 mmol/L) and anemia (< 110 g/L), respectively. The prevalence of stunting was 5.8%, that of overweight 3.8%, and that of underweight 0.4%. W/H z-scores were lower and statistically significant in children aged 12-36 months. An association was also found between W/H z-scores and maternal height. This association was also observed regarding body mass index. H/A z-scores were lower and statistically significant in low birth weight children. Lower hemoglobin concentrations were detected in children aged 12-36 months who were not receiving the financial support of the Bolsa Familia (Family Allowance) program. There was no significant association between vitamin A, iron and zinc deficiencies and the anthropometric indices studied.

La dieta: un principio básico en el tratamiento de la disglucemia / Diet: a basic principle in the treatment of dysglycemia

Se revisó la bibliografía médica relacionada con la dietoterapia en los estados de disglucemia: desequilibrio metabólico de los carbohidratos que comienza a producirse desde la fase prediabética hasta la diabetes mellitus como tal, de cuyo análisis se extrajeron y resumieron aspectos básicos concernientes a características de la alteración, principios nutricionales, cálculo de la dieta según peso ideal e índice de masa corporal, así como importancia del tratamiento no farmacológico para prevenir la diabetes sacarina u otras complicaciones de esta enfermedad a largo plazo.

The medical literature related to the dietotherapy in the dysglycemia states was reviewed: metabolic imbalance of carbohydrates which begins to take place from the prediabetic phase to the diabetes mellitus as such. From its analysis, basic aspects concerning the characteristics of the change, nutritional principles, calculation of the diet according to the ideal weight and body mass index were collected and summarized, as well as the importance of the non pharmacological treatment to prevent the diabetes mellitus or other complications of this long term disease.

Periorificial and acral dermatitis in a newborn having milk intolerence.

A 2-week-old infant born at 36-week gestation developed diarrhea and metabolic acidosis when he was put on formula feeding. He was treated for sepsis and was screened for metabolic diseases. Blood and cerebrospinal fluid cultures were clear. The diarrhea and metabolic acidosis settled but recurred when formula feeding was resumed. He developed a florid erythematous rash involving the palms, feet, perioral and perineal regions. Zinc deficiency was confirmed and zinc replacement resulted in prompt resolution of the skin rash. The patient was put on Pepti-Junior and remained well. This case illustrates that zinc deficiency must be sought and treated in an infant with a typical rash involving the palms, feet and body orifices.

El zinc en la salud humana - II / Zinc in human health - II

Zinc is a divalent cation with multiple functions in the human body. Zinc absorption occurs in the small intestine and is, together with its excretion via faeces, the point of control for zinc homeostasis. Zinc is an essential nutrient with a specific role in more than 300 enzymes, which participate in all important biochemical reactions of the human body. Therefore, zinc status has a direct effect in growth, neurological and behavioral development and in the immune system. The diagnosis of zinc deficiency in individuals is not yet possible given that there still is no indicator with adequate sensitivity. Nevertheless, it is acceptable to use serum zinc levels to evaluate populations. Finally, intervention strategies such as supplementation, food fortification and/or dietary modification can be used to control and/or prevent zinc deficiency.

El zinc es un catión divalente con múltiples funciones en el cuerpo humano. La absorción de zinc ocurre en el intestino delgado y es junto con la excreción de zinc por las heces, uno de los dos puntos de control de la homeostasis de zinc. El zinc es un nutriente esencial con un rol específico en más de 300 enzimas, las cuales participan en todas las reacciones bioquímicas importantes del cuerpo humano. Por ende, el estado de la nutrición de zinc tiene un efecto directo en el crecimiento, el desarrollo neurológico y de comportamiento y en el sistema inmune. El diagnóstico de deficiencia de zinc en seres humanos no es posible pues aun no existe un marcador lo suficientemente sensible. Sin embargo, el zinc sérico es aceptable para evaluar poblaciones. Finalmente, se pueden usar las estrategias de suplementación, fortificación y/o modificación alimentaria para controlar y/o prevenir la deficiencia de este elemento.

Micronutrientes envolvidos no crescimento / Micronutrients involved in growth

Os hábitos alimentares infantis têm sofrido modificações drásticas nas ultimas décadas. A aversão a frutas, verduras, carnes e laticínios, juntamente à predileção por produtos artificiais e industrializados observada entre crianças, tem despertado preocupação entre os profissionais da saúde. Isso porque estudos têm demonstrado a influência negativa do consumo insuficiente de alguns nutrientes no crescimento e desenvolvimento infantil. Cientes deste problema, desenvolvemos este artigo visando esclarecer algumas dúvidas quanto a função e importância de alguns micronutrientes como o zinco, ferro, vitamina A, ácido fólico, cálcio e vitamina D, bem como suas recomendações nutricionais, como auxilio a elaboração de tratamento e estratégias nutricionais que poderão garantir o crescimento e desenvolvimento normais entre as crianças

The infant habits have suffered drastic alterations in the last decades. The avoidance of fruits, vegetables, meat and milk products, with the preference to artificial and industrialized products observed among children have raised concerned among the health working groups. This is due to the studies that have demonstrated the negative influence of insufficient intake of some nutrients on infant growth and developing. Considering this problem, we wrote this article to clarify some doubts about the functions and importance of some micronutrients such as zinc, iron, vitamin A, folic acid, calcium and vitamin D, as well as nutritional recommendations, as a contribution to the elaboration of treatment and nutritional strategies that would ensure children growth and development

Manifestaciones cutáneas de deficiencias nutricionales / Skin manifestations of nutritional deficiencies

Las enfermedades malabsortivas son las más importantes en ilustrar deficiencias nutricionales y se caracterizan por alteración en la absorción de uno o varios nutrientes en el intestino delgado. Se manifiestan clínicamente con diarrea, anemia, baja de peso, hipoalbuminemia o deficiencias nutricionales específicas. El compromiso cutáneo en las enfermedades malabsortivas es frecuente y podría corresponder al primer signo clínicamente reconocible de deficiencias nutricionales que amenazan la vida. Los principales signos asociados a malabsorción de nutrientes son ictiosis, hiperpigmentación cutánea, keratosis folicular, púrpura, dermatitis eccematosas, alopecia, patología ungueal y compromiso de mucosas. Merecen especial mención las lesiones cutáneas asociadas a enfermedad celíaca, dermatitis herpetiforme, acrodermatitis enteropática y enfermedad de Whipple. En este artículo se revisarán las manifestaciones cutáneas de la malabsorción intestinal generalizada y de las deficiencias de nutrientes específicos.

Profile of iodine content of salt and urinary iodine excretion levels in selected districts of Tamil Nadu.

OBJECTIVE: Iodine deficiency disorders (IDD) is the most common cause of preventable mental retardation in world today. Out of 29 districts in Tamil Nadu, 24 have been surveyed and all have been found to be endemic to IDD. There is a complete ban on the sale of non iodised salt in the state since 1995. The present study was conducted to assess the iodine content of salt and urinary iodine excretion levels amongst the beneficiaries in the state to help the government to strengthen the existing Universal salt iodisation (USI) programme activities. METHODS: The study was undertaken in 24 districts of Tamil Nadu during the year 2001. The guidelines recommended by WHO/UNICEF/ICCIDD for a rapid assessment of salt iodisation in a district was adopted. A minimum of 150 salt samples were collected from each district by utilising the uniform sampling methodology. The iodine content of salt samples was analysed using the standard iodometric titration method. At least 60 children from each school were randomly selected and were requested to provide "on the spot" casual urine samples. The urinary iodine excretion (UIE) levels were analysed using the wet digestion method. RESULTS: It was observed that 62.3% of the families were consuming iodised salt with more than 5 ppm of iodine. It was found that district Perambalour had deficient iodine nutriture as revealed by the median UIE levels less than 100 micro g/l. CONCLUSION: The findings of the present study reveals the success of USI programme and highlights need for continued monitoring of the quality of salt provided to the population in order to achieve the goal of IDD elimination.

Elimination of iodine deficiency disorders in Delhi.

OBJECTIVE: The present study was conducted in year 2002 in NCT of Delhi with the objective to re-assess the prevalence of iodine deficiency disorders. METHODS: A total of 7009 children in the age group of 6-11 years were clinically examined for presence of goiter. A total of 991 salt samples were also collected randomly. On the spot casual urine samples were collected from 1395 children. RESULTS: The total goiter prevalence was found to be 6.2%. The percentage of children with urinary iodine excretion (UIE) of < 20.0, 20.0- < 50.0, 50.0-99.9 and 100.0 microg/l and above was 0.8, 1.8, 8.7 and 88.7%, respectively. The median UIE level was 200 microg/L. The assessment of iodine content of salt revealed that only 16% of the families were consuming salt with iodine content less than 5 ppm. CONCLUSION: The findings of the present study indicated that the population is in a transition phase from iodine deficient (as revealed by Total Goiter Prevalence) to iodine sufficient nutriture (as revealed by median UIE 200 microg/l). A significant progress has been achieved towards elimination of IDD from NCT of Delhi.

Moléstias associadas à carência crônica de iodo / Disorders associated to chronic iodine deficiency

Fundamentalmente, a glândula tiróide, face à carência de iodo, se adapta por incremento da captação deste halogênio, aumenta a sua massa glandular (bócio), induz secreção preferencial de T3 e eleva a síntese e liberação de TSH. Os exames laboratoriais e de imagem permitem a comprovação dos mecanismos adaptativos. A iodúria permite avaliação quantitativa do grau de carência iódica. Em algumas populações, coexiste a influência de bocígenos naturais presentes nos alimentos consumidos localmente. O cretinismo endêmico é síndrome neurológica e endócrina que conduz o indivíduo a quadro severo de rebaixamento mental e surdo-mudez. No Brasil, as moléstias associadas à carência de iodo foram sempre avaliadas por inquéritos nacionais em escolares. A correção da deficiência de iodo se faz pela adição de iodato de potássio ao sal de consumo humano. Várias leis e decretos foram elaborados tentando aperfeiçoar o sistema universal de iodação do sal, que, mais recentemente, foi aprimorado e tornou-se mais eficiente em propiciar iodo a toda população brasileira.

Clinical, biochemical and cytomorphological observations in juvenile chronic lymphocytic thyroiditis.

OBJECTIVE: To determine the clinical, biochemical, ultrasonological and cytomorphological features in goitrous juvenile chronic lymphocytic thyroiditis(CLT). SETTING: Tertiary referral center for thyroid disorders. SUBJECTS: A total of 455 children were evaluated for goiter. Of these 122 children had features of CLT in FNAC and were further studied. METHODS: All subjects were subjected to detailed clinical examination. The thyroid functional status was assessed by estimation of serum concentration of thyroid hormones (thyroxine and triiodothyronine) and thyrotropin (TSH). In addition the antithyroid antibody titers were measured. Ultrasonological and cytomorphological characteristics in these patients were also evaluated. RESULTS: The mean age at presentation was 12.5 years (SD 3.93). The male: female ratio was 1:7.7. Thyroid functional status as assessed by serum thyroxine and thyrotropin levels revealed, euthyroidism in 67 (54.9%), hypothyroidism in 30 (24.6%), subclinical hypothyroidism in 22 (18%) and hyperthyroidism in 3 (2.5%). Thyroid antimicrosomal antibodies were detected in significant titers in 90 (73.8%) and antithyroglobulin was positive in 71 (58.2%). The positivity of the antimicrosomal and antithyroglobulin antibodies were much higher in subjects with hypothyroidism and was detected in 86.5% and 69.2%, respectively. The mean urinary iodine excretion was 74.1 micrograms/g of creatinine (SD 31.4) indicating mild iodine deficiency. Fine needle aspiration cytoloty (FNAC) revealed features of chronic lymphocytic thyroiditis. Hurthle cell changes was seen in only 12% of the cases. The epithelium was more often hyperplastic and vacuolation of the cytoplasm and peripheral vacuolations were seen frequently. Giant cells and epithelioid cells were seen in many cases. CONCLUSIONS: In any child presenting with firm goiter, a diagnosis of CLT should be excluded. Many subjects with juvenile CLT have biochemical evidence of hypothyroidism but only few symptoms or clinical features.

Factores condicionantes, base para la salud bucal / Conditioning factors, basis for oral health

Se detallan signos y síntomas de cuadros subclínicos de deficienias nutricionales, en pacientes atendidos en consultorios odontológicos. Descubrirlos a tiempo, permite efectuar acciones de protección y prevención de la salud, induciendo cambios en su alimentación. Lo importante es mejorar el nivel de vida, modificando de a poco, gradualmente, los malos hábitos higiénico dietéticos individuales para acostumbrarse a una alimentación variada y equilibrada, comiendo de todo moderadamente, evitando así los excesos

Assessment of iodine deficiency in selected blocks of east and west Champaran districts of Bihar.

OBJECTIVE: A survey conducted in 1964 reported a goitre prevalence of 40.3% in East and West Champaran districts of Bihar. No recent survey has been documented on the prevalence of iodine deficiency in these districts. The present study was therefore undertaken (i) to assess the prevalence of IDD in these districts, and (ii) to estimate the iodine content of salt consumed by population. METHODOLOGY: In each district, one block was selected. In each block more than 630 children in the age group of 6-12 years were included in the study and were clinically examined. Urine samples were collected from 261 children and were analyzed using standard laboratory procedures. A total of 456 salt samples were collected from children and 35 from traders from the two districts and analyzed using the standard iodometric titration method. RESULTS: The total goiter prevalence was 11.6%. The percentage of children with < 2, 2.0-4.9, 5.0-9.9 and > or = 10 mcg/dl of urinary iodine excretion level were 12.3, 13.4, 23.4 and 51.0, respectively. The median urinary iodine excretion of the children was 10.0 mcg/dl. None of the families were consuming salt with a nil iodine content and about 29.3%, were consuming salt with less than 15 ppm of iodine. Of the 35 salt samples collected from traders, all had iodine and about 17% had less than 15 ppm of iodine. CONCLUSION: The study stresses the need for strengthening the existing system of monitoring of quality of salt being provided in the East and West Champaran districts by Government of Bihar.

Nutritional deficiencies and subsequent effects on mental and behavioral development in children.

Nutritional deficiencies at all stages of growth, both pre- and post-natal, can affect a child's physical, mental and behavioral development. In this paper, we review literature about how mental development is affected by the following nutritional conditions: low birth weight, mild, moderate, and severe protein-energy malnutrition, iodine deficiency, and iron deficiency.

Nutrition and development: other micronutrients' effect on growth and cognition.

Previous studies have provided strong evidence that protein-energy malnutrition, deficiencies of iron and iodine early on in life led to compromised growth and cognitive functions in young children. Recently, a growing body of knowledge indicated that other micronutrients also play a role in young child development. Severe as well as marginal vitamin A efficiency were shown to lead to an increased risk of morbidity and mortality in children. A meta-analysis of vitamin A intervention trials indicated an overall reduction of 23% in all-cause mortality rate. Delayed growth, especially stunting, was reported in children with clinical signs of vitamin A deficiency. In addition, deficiency of zinc, which is essential for DNA and protein synthesis, leads to growth failure and delayed secondary sexual maturation in man and animals. Preterm infants appear to benefit from zinc administration in terms of growth and development. Supplementation studies in infants and older children revealed that those who manifested overt zinc deficiency through either clinical or biochemical indicators showed an improvement in linear growth and occasionally, an increase in weight gain. Zinc may also play a major role in brain function based on strong evidence from experimental animals. Zinc deficiency gestation in mice, rats, rhesus monkeys caused impaired learning, reduced attention and poor memory in their offspring. Data in humans are few and inconclusive. With respect to brain function alone, other nutrients such as docosahexaenoic acid (DHA, 22:6 n-3 fatty acid) improve visual acuity and mental development in small-for-gestational-age infants, folate supplementation during pregnancy prevents neural tube defect in infants, selenium deficiency in animals affects activities of brain enzymes necessary for brain development and function. Although evidence is accumulating that micronutrients other than iron and iodine may be important for physical growth and brain development in young children, more well-controlled studies in humans are needed. Critical issues to be considered include: single vs multiple limiting nutrients, critical period of deficiency, responsive indicators and variables that may affect the results as environmental, psychological and social factors.