ABSTRACT Background: In adolescents, the recommended daily intake (RDI) of calcium is 1,300 mg. In Chile, the latest National Survey of Food Consumption showed that the median total calcium intake was less than half of the RDI. An adequate intake of calcium in adolescence negatively affects BMD. Aim: To determine the association of calcium intake and nutritional status with bone mineral density (BMD) in male and female adolescents with completed pubertal development (Tanner 5). Methods: Cross-sectional study in a random sample of 79 male and female adolescents, ages 17-18. Participants were healthy, Tanner stage 5, and BMI <35 kg/m2. Three 24-hour recall questionnaires determined food intake. Weight, height, and waist circumference were measured, and BMI was estimated. Bone mineral density (BMD) was also measured. Results: Sixty-eight percent of adolescents had less than 50% of the recommended daily intake (RDI) for calcium. Mean calcium intake was 658±328mg/d and 568±299 mg/d in males and females, respectively. In both sexes, the mean standardized BMD was normal or > −1 SD. BMD was higher in obese participants compared to normal-weight adolescents (1.05±0.85 vs 0.33±0.86; P= 0.04), although no differences in nutrients and food intake. Calcium intake was unrelated to total bone mass and unstandardized BMD. Conclusions: In our sample of adolescents with complete pubertal development, there was no relationship between calcium intake and bone mineralization levels. There was a significant relationship between bone mineralization and nutritional status, with BMD being higher in adolescents with obesity.

RESUMEN Introducción: La cantidad diaria recomendada (RDA) de calcio en adolescentes es de 1.300 mg/día. La última Encuesta Nacional de Consumo Alimentario de Chile, mostró que la mediana de ingesta total de calcio fue menos de la mitad de la RDA. Una ingesta insuficiente de calcio puede impactar negativamente la mineralización ósea. Objetivo: Determinar el efecto de la ingesta de calcio y estado nutricional sobre la densidad mineral ósea (DMO) de adolescentes con desarrollo puberal completo. Métodos: Estudio de corte transversal. Participaron n= 79 adolescentes de ambos sexos de entre 17 y 18 años elegidos al azar, aparentemente sanos, estadio Tanner 5 e IMC<35 kg/m2. Se determinó ingesta alimentaria por encuesta recordatorio 24 horas. Se midió peso, talla, circunferencia de cintura, DMO y calcio sérico (mg/dl). Se estimaron IMC, IMC estandarizado y DMO estandarizada. Resultados: En la muestra (51% mujeres) el 18% tenía obesidad y el 25%, sobrepeso. Un 68% de los adolescentes ingirió menos del 50% de la recomendación de ingesta de calcio. El consumo promedio de calcio fue de 658±328mg/d y 568±299 mg/d en hombres y mujeres, respectivamente. La DMO estandarizada (puntaje Z) fue normal para ambos sexos (>-1 DE). Según estado nutricional, no hubo diferencias significativas en la ingesta de nutrientes, pero sí en la DMO. En media, la DMO estandarizada (puntaje Z) fue normal para ambos sexos (>-1 DE); los adolescentes con obesidad presentaron una DMO estandarizada significativamente mayor que los adolescentes de peso normal (1,05±0,85 vs 0.33±0,86; P= 0,04). La ingesta de calcio no se relacionó con la masa ósea total ni con la DMO estandarizada. Conclusión: En adolescentes con desarrollo puberal completo no hubo relación entre la ingesta de calcio y los niveles de mineralización ósea. Sí hubo relación entre mineralización ósea y estado nutricional, siendo mayor la DMO en los individuos con obesidad.

El perfil lipídico depende de muchos factores. Sin embargo, las variaciones estacionales de estos componentes han sido escasamente establecidas en el hemisferio sur. El objetivo de este estudio fue determinar la variación estacional del perfil lipídico por un periodo de un año en un grupo de adultos aparentemente sanos de Santiago, Chile. El diseño del estudio fue observacional y prospectivo. Participaron en el estudio 50 voluntarios sanos de ambos sexos y de edades entre 23 a 62 años. En forma mensual y durante un año se midió el perfil lipídico. LDL fue significativamente mayor en invierno y primavera que en verano (p<0,01). Por el contrario HDL disminuye en invierno (p<0,05). Se concluye que existen variaciones estacionales en los niveles séricos de LDL y HDL. El patrón circanual está caracterizado por mayores niveles de LDL en invierno y primavera y menores niveles de HDL en invierno.

The lipid profile is impacted by numerous factors. However, the seasonal variations in this profile have not been well-established in the southern hemisphere. The aim of this study was to determine the seasonal variation of the lipid profile in apparently healthy adults from Santiago, Chile. The study design was observational and prospective, involving 50 healthy volunteers of both genders, aged 23-62 years. The lipid profile was measured at monthly intervals over the course of one year. LDL was significantly higher in winter -spring than in summer- fall (p <0.01). Conversely, HDL decreases significantly in winter (p<0,05). We conclude that there are seasonal variations in the serum levels of LDL and HDL. The circannual pattern is characterized by increased levels of LDL in winter-spring and low levels of HDL in winter.

El objetivo del presente estudio es evaluar el estado nutricional e ingesta de hierro (Fe), zinc (Zn) y cobre (Cu) en mujeres chilenas en edad fértil. Se estudió una muestra de conveniencia de 86 mujeres entre 18 a 48 años de edad de la ciudad de Santiago, Chile. El estado nutricional de Fe se determinó a través de hemoglobina (Hb), volumen corpuscular medio, saturación de transferrina, zinc protoporfirina, ferritina sérica (FS), Zn y Cu séricos. La ingesta dietética fue evaluada con una encuesta de frecuencia de consumo. Un 4,7% de las mujeres presentó anemia por deficiencia de Fe, 21% deficiencia de Fe sin anemia, 26% depósitos depletados de Fe y un 48,3% estado nutricional normal de Fe. Las mujeres obesas presentaron mayores niveles de FS (p<0,01) al comparar con mujeres con peso normal. Además, presentaron niveles más altos de Hb (p<0,05) al comparar con mujeres con estado nutricional normal y sobrepeso. El 3,5% y 2,3% de las mujeres presentó deficiencia de Zn y Cu, respectivamente. El 95%, 94% y 99% cumplió el EAR para Fe, Zn y Cu, respectivamente. No se encontraron diferencias significativas en la ingesta de micronutrientes entre las mujeres al comparar por estado nutricional. En conclusión, un alto porcentaje de las mujeres presentó una ingesta adecuada de micronutrientes. Además existe una baja prevalencia de deficiencia de Zn, Cu y anemia. Sin embargo, un 47% presenta deficiencia de Fe en etapas anteriores a la de anemia.

The aim of the present study was to evaluate anemia, the biochemical status and dietary adequacy of iron (Fe), zinc (Zn) and copper (Cu), in Chilean childbearing age women. We studied a convenience sample of 86 women aged 18 to 48 years from Santiago, Chile. We determined anemia and the micronutrient status through hemoglobin (Hb) mean corpuscular volume, transferrin saturation, zinc protoporphyrin, serum ferritin (SF), serum Zn and Cu. Dietary adequacy was estimated using a food frequency questionnaire. Of all women, 4.7% had Fe deficiency (ID) anemia, 21 % ID without anemia, 26 % depleted Fe stores and 48.3% normal Fe status. Obese women had higher SF (p<0.01) compared with those classified as having normal BMI. Also, showed higher Hb (p<0.05) concentrations compared with overweight and normal weight women. Participants showed 3.5 % and 2.3 % of Zn and Cu deficiency, respectively. Also, 95 %, 94 % and 99 % had adequate intake of Fe, Zn and Cu respectively, according to EAR cut points. There were no significant differences in micronutrients intake across different nutritional status. There was a low prevalence of anemia, Fe, Zn and Cu deficiency. A high percentage of women reached micronutrient adequacy. However, 47% of women had ID without anemia and Fe depleted stores.

Objective. To determine the prevalence of anemia and iron status among Chilean women of childbearing age between 1981 and 2010. Materials and methods. Calculation of the prevalence of anemia and iron status was based on multiple cross-sectional iron absorption studies performed in 888 women during this period of time. All studies included measurements of hemoglobin, mean corpuscular volume, zinc protoporphyrin, percentage of transferrin saturation and serum ferritin. Data were grouped by decade (1981-1990, 1991-2000, and 2001-2010). Results. Prevalence of anemia for these decades was 9, 6 and 10%, respectively (p=NS). Iron deficiency anemia was the main cause of anemia in all periods (55, 85 and 75%, respectively; p=NS). A high prevalence of women with normal iron status was observed for all periods (64, 69, and 67, respectively; p=NS). Prevalence of iron deficiency without anemia in 1981-1990, 1991-2000 and 2001-2010 was 7, 20 and 12%, respectively (p<0.05). Finally, prevalence of iron depleted stores was 20, 6 and 10%, respectively (p<0.05). Conclusions. Prevalence of iron deficiency anemia in Chilean women of childbearing age was mild between 1981 and 2010. More than 60% of childbearing age women presented normal iron status in all periods. However, prevalence of iron depleted stores was moderate during 1981-1990, and was mild during 1991-2000 and 2001-2010.

Objetivo. Determinar la prevalencia de anemia y el estado de nutrición de hierro entre 1981 y 2010 en mujeres chilenas en edad fértil. Material y métodos. La prevalencia de anemia y el estado de nutrición de hierro fueron calculados con base en múltiples estudios transversales de absorción de hierro realizados en 888 mujeres. Estos estudios incluían medición de hemoglobina, volumen corpuscular medio, zinc protoporfirina, porcentaje de saturación de transferrina y ferritina sérica. Los datos fueron agrupados por décadas (1981-1990, 1991-2000, y 2001-2010). Resultados. La prevalencia de anemia para estas décadas fue de 9, 6 y 10%, respectivamente (p=NS). La anemia por deficiencia de hierro fue la principal causa de anemia en los periodos evaluados (55, 85 y 75%, respectivamente; p=NS). Una alta prevalencia de mujeres con estado de nutrición normal de hierro fue observado en todos los periodos (64, 69, y 67%, respectivamente; p=NS). La prevalencia de deficiencia de hierro sin anemia fue de 7, 20 y 12%, respectivamente (p<0.05). Finalmente, la prevalencia de depleción de depósitos de hierro fue de 20, 6 y 10%, respectivamente (p<0.05). Conclusiones. La prevalencia de anemia por deficiencia de hierro en mujeres chilenas en edad fértil clasifica como leve entre 1981 y 2010. Más de 60% de las mujeres en edad fértil presentó estado nutricional normal de hierro en todos los periodos. Sin embargo, la depleción de depósitos de hierro fue moderada durante 1981-1990, y fue leve durante 1991-2000 y 2001-2010.

Objective. To determine the prevalence of anemia and iron status among Chilean women of childbearing age between 1981 and 2010. Materials and methods. Calculation of the prevalence of anemia and iron status was based on multiple cross-sectional iron absorption studies performed in 888 women during this period of time. All studies included measurements of hemoglobin, mean corpuscular volume, zinc protoporphyrin, percentage of transferrin saturation and serum ferritin. Data were grouped by decade (1981-1990, 1991-2000, and 2001-2010). Results. Prevalence of anemia for these decades was 9, 6 and 10%, respectively (p=NS). Iron deficiency anemia was the main cause of anemia in all periods (55, 85 and 75%, respectively; p=NS). A high prevalence of women with normal iron status was observed for all periods (64, 69, and 67, respectively; p=NS). Prevalence of iron deficiency without anemia in 1981-1990, 1991-2000 and 2001-2010 was 7, 20 and 12%, respectively (p<0.05). Finally, prevalence of iron depleted stores was 20, 6 and 10%, respectively (p<0.05). Conclusions. Prevalence of iron deficiency anemia in Chilean women of childbearing age was mild between 1981 and 2010. More than 60% of childbearing age women presented normal iron status in all periods. However, prevalence of iron depleted stores was moderate during 1981-1990, and was mild during 1991-2000 and 2001-2010.

Objetivo. Determinar la prevalencia de anemia y el estado de nutrición de hierro entre 1981 y 2010 en mujeres chilenas en edad fértil. Material y métodos. La prevalencia de anemia y el estado de nutrición de hierro fueron calculados con base en múltiples estudios transversales de absorción de hierro realizados en 888 mujeres. Estos estudios incluían medición de hemoglobina, volumen corpuscular medio, zinc protoporfirina, porcentaje de saturación de transferrina y ferritina sérica. Los datos fueron agrupados por décadas (1981-1990, 1991-2000, y 2001-2010). Resultados. La prevalencia de anemia para estas décadas fue de 9, 6 y 10%, respectivamente (p=NS). La anemia por deficiencia de hierro fue la principal causa de anemia en los periodos evaluados (55, 85 y 75%, respectivamente; p=NS). Una alta prevalencia de mujeres con estado de nutrición normal de hierro fue observado en todos los periodos (64, 69, y 67%, respectivamente; p=NS). La prevalencia de deficiencia de hierro sin anemia fue de 7, 20 y 12%, respectivamente (p<0.05). Finalmente, la prevalencia de depleción de depósitos de hierro fue de 20, 6 y 10%, respectivamente (p<0.05). Conclusiones. La prevalencia de anemia por deficiencia de hierro en mujeres chilenas en edad fértil clasifica como leve entre 1981 y 2010. Más de 60% de las mujeres en edad fértil presentó estado nutricional normal de hierro en todos los periodos. Sin embargo, la depleción de depósitos de hierro fue moderada durante 1981-1990, y fue leve durante 1991-2000 y 2001-2010.

During the past decade the role of folate and vitamin B12 in human nutrition have been under constant re-examination. Basic knowledge on the metabolism and interactions between these essential nutrients has expanded and multiple complexities have been unraveled. These micronutrients have shared functions and intertwined metabolic pathways that define the size of the "methyl donor" pool utilized in multiple metabolic pathways; these include DNA methylation and synthesis of nucleic acids. In Chile, folate deficiency is virtually nonexistent, while vitamin B12 deficiency affects approximately 8.5-51% depending on the cut-off value used to define deficiency. Folate is found naturally mainly in vegetables or added as folic acid to staple foods. Vitamin B12 in its natural form is present only in foods of animal origin, which is why deficit is more common among strict vegetarians and populations with a low intake of animal foods. Poorfolate status in vulnerable women of childbearing age increases the risk of neural tube birth defects, so the critical time for the contribution of folic acid is several months before conception since neural tube closure occurs during the first weeks of life. The absorption of vitamin B12 from food is lower in older adults, who are considered to have higher risk of gastric mucosa atrophy, altered production of intrinsic factor and acid secretion. Deficiency of these vitamins is associated with hematological disorders. Vitamin B12 deficiency can also induce clinical and sub-clinical neurological and of other disorders. The purpose of this review is to provide an update on recent advances in the basic and applied knowledge of these vitamins relative to human health.

Background: Older subjects have a high risk of developing zinc and copper deficiencies. Aim: To determine the prevalence of copper and zinc deficiencies in adults aged over 60 years, living in Metropolitan Santiago. Subjects and Methods: Analyses were performed using anonymous serum samplesfrom older subjects living in Santiago, Chile, who participated in the multicenter project SABE. Of the studied subjects, 49.3% had enough left over serum to measure serum zinc and copper concentrations by atomic absorption spectrometry. Results: A total of444 men and 198 women were studied. A positive correlation between serum zinc and copper was found in both women (r = 0.44, p < 0.001) and men (r = 0.48, p < 0.001). There were no differences in serum zinc concentration by sex and age. The prevalence of subnormal serum zinc valúes was 66.9% in women and 66.7% in men. Women had a significantly higher serum copper valúes than men (p < 0.02) and there were no differences by age. Prevalence of subnormal serum copper valúes was higher in women than in men (32.9 and 23.7% respectively, p < 0.05). Women had significantly higher copper I zinc serum ratio than men (p < 0.001). Conclusions: Older people living in Metropolitan Santiago have a high prevalence of copper and zinc deficiencies.

The effects of gastric bypass (GBP) on resting energy expenditure (REE) are not well known. Aim: To evaluate the changes in REE and its relationship with body composition in severe and morbid obese women before and six and twelve months after GBP. Patients and methods: Twenty three women aged 37±10 years, with a body mass index of 44±4 kg/m², were evaluated before, six and twelve months after GBP. REE was measured in a Deltatrac indirect calorimeter and expressed as kcal/day Fat mass (EM), and fat free mass (EEM) were determined by double beam Xray densitometry (DEXA). Results: Body weight reduction six and twelve months after GBP was 29.0±4.3 and 35.8±6.9%, respectively. The best predictor of weight reduction was initial weight (p <0.01). At six and twelve months, REE decreased by 291.7±260.0 and 353.8±378.4 kcal/day, respectively. In the same periods REE/kg body weight increased by 3.3 and 4.8 kcal/kg respectively, compared to baseline. REE/kg EEM was unchanged. Conclusions: GBP was associated with significant changes in body composition after six and twelve months. However, despite weight reduction, resting energy expenditure per fat free mass unit did not change significantly

Interactions of micronutrients can affect absorption and bioavailability of other nutrients by a number of mechanisms. In aqueous solutions, and at higher uptake levels, competition between elements with similar chemical characteristics and uptake process can take place. The consequences of these interactions may depend on the relative concentrations of the nutrients. In this work, we measure the effects of increasing concentrations of iron, zinc, and copper on iron and copper uptake in Caco-2 cells. Intracellular Fe or Cu levels were affected by incubating with increased concentrations of metals. However, when the cells already had different intracellular metal concentration, the uptake of Fe or Cu was nor affected. In competition studies, we showed that Cu and Zn inhibited Fe uptake, and while Fe inhibited Cu uptake, Zn did not. When the three metals were given together (1: 1: 1 ratio), Fe or Cu uptake was inhibited ~40%. These results point to a potential risk in the absorption and bioavailability of these minerals by the presence of other minerals in the diet. This aspect must be considered in food supplementation and fortification programs.

Iron deficiency is the most prevalent nutritional deficiency and the main cause of anemia worldwide. Apart from anemia effects, other non-hematological manifestations have been described, such as decreased capacity for physical work and spontaneous motor activity, impairment of cell-mediated immunity and bactericidal capacity of neutrophils, decreased thermoregulation, functional and histological abnormalities of the gastrointestinal tract, defective mobilization of liver vitamin A, increased risk of premature labor, low birth-weight and perinatal morbidity, reduced iron transfer to the fetus and growth retardation, behavioral disorders and mental and motor development delays, decreased auditory and visual systems nerve conduction velocity, as well as reduction of the vagal tone. The prevention of iron deficiency can be accomplished by changes in dietary patterns, food fortification and iron supplementation.

La deficiencia de hierro es la deficiencia nutricional más prevalente y la principal causa de anemia a escala mundial. Además de las manifestaciones propias de la anemia, se han descrito otras manifestaciones no hematológicas tales como: disminución de la capacidad de trabajo físico y de la actividad motora espontánea, alteraciones de la inmunidad celular y de la capacidad bactericida de los neutrófilos, disminución de la termogénesis, alteraciones funcionales e histológicas del tubo digestivo, falla en la movilización de la vitamina A hepática, mayor riesgo de parto prematuro, bajo peso de nacimiento y de morbilidad perinatal, menor transferencia de hierro al feto, una disminución de la velocidad de crecimiento, alteraciones conductuales y del desarrollo mental y motor, velocidad de conducción más lenta de los sistemas sensoriales auditivo y visual, y reducción del tono vagal. La prevención de la deficiencia de hierro incluye cambios en los hábitos alimentarios, fortificación de los alimentos y la suplementación con hierro.