Prevalence of Anemia and Iron Deficiency in Women of Reproductive Age in Cuba and Associated Factors.

This study aims to evaluate the prevalence of anemia and iron deficiency in women of reproductive age and the association with inflammation, global overweight, adiposity, and menorrhagia. A sample design of women of reproductive age from the Eastern, Central, and Havana Regions was carried out. Biochemical determinations of hemoglobin, serum ferritin, soluble transferrin receptors, leukocytes, C-reactive protein, alpha-1 acid glycoprotein, and homocysteine were performed. Serum ferritin was also adjusted by inflammation. Nutritional status was assessed, and menstrual characteristics were collected by survey. A total of 742 women were studied. The prevalence of anemia was 21.4%, iron storage deficiency at 16.0%, and erythropoietic dysfunction at 5.4%, with inflammation at 47.0% and elevated homocysteine at 18.6%. Global overweight was 46.2% and increased adiposity at 58.4%. Anemia is associated with iron deposition deficiency (OR = 3.023 (1.816-5.033)) and with erythropoietic deficiency (OR = 5.62 (3.03-10.39)), but not with inflammation, global overweight, and adiposity. Global overweight was found to be associated with inflammation (OR = 2.23 (1.41-3.53)). Anemia was associated with heavy menstrual bleeding (OR = 1.92 (1.34-2.76)). Homocysteine was associated with inflammation (OR = 2.05 (1.08-3.90)), but not with anemia. In conclusion, anemia in Cuba is classified as a moderate public health problem, but not iron deficiency. A high prevalence of overweight and obesity was found, associated with inflammation, but not with anemia or iron deficiency. Heavy menstrual bleeding is a factor associated with anemia.

Adjusting Iron Deficiency for Inflammation in Cuban Children Aged Under Five Years: New Approaches Using Quadratic and Quantile Regression.

INTRODUCTION: Ferritin is the best biomarker for assessing iron deficiency, but ferritin concentrations increase with inflammation. Several adjustment methods have been proposed to account for inflammation's effect on iron biomarker interpretation. The most recent and highly recommended method uses linear regression models, but more research is needed on other models that may better define iron status in children, particularly when distributions are heterogenous and in contexts where the effect of inflammation on ferritin is not linear. OBJECTIVE: Assess the utility and relevance of quadratic regression models and quantile quadratic regression models in adjusting ferritin concentration in the presence of inflammation. METHODS: We used data from children aged under five years, taken from Cuba's national anemia and iron deficiency survey, which was carried out from 2015-2018 by the National Hygiene, Epidemiology and Microbiology Institute. We included data from 1375 children aged 6 to 59 months and collected ferritin concentrations and two biomarkers for inflammation: C-reactive protein and α-1 acid glycoprotein. Quadratic regression and quantile regression models were used to adjust for changes in ferritin concentration in the presence of inflammation. RESULTS: Unadjusted iron deficiency prevalence was 23% (316/1375). Inflammation-adjusted ferritin values increased iron-deficiency prevalence by 2.6-4.5 percentage points when quadratic regression correction model was used, and by 2.8-6.2 when quantile regression was used. The increase when using the quantile regression correction model was more pronounced and statistically significant when both inflammation biomarkers were considered, but adjusted prevalence was similar between the two correction methods when only one biomarker was analyzed. CONCLUSIONS: The use of quadratic regression and quantile quadratic regression models is a complementary strategy in adjusting ferritin for inflammation, and is preferable to standard regression analysis when the linear model's basic assumptions are not met, or when it can be assumed that ferritin-inflammation relationships within a subpopulation may deviate from average trends.

Influence of Inflammation on Assessing Iron-Deficiency Anemia in Cuban Preschool Children.

INTRODUCTION: Anemia is a public health problem worldwide and is most prevalent in preschool children, for whom it is the most frequent cause of nutritional deficits. In turn, iron deficiency is the main cause of anemia, affecting 43% of children globally. Previous studies in Cuba show rates of iron deficiency in preschool children between 38.6% and 57.6%, higher in infants (71.2% to 81.1%). WHO recommends using serum ferritin as an indicator of iron deficiency accompanied by acute (C-reactive protein) and chronic (a1-acid glycoprotein) inflammation biomarkers. OBJECTIVE: Assess how inflammation affects measuring and reporting of iron-deficiency anemia rates in Cuban preschool children. METHODS: Data were obtained from serum samples contained in the National Anemia and Iron Deficiency Survey, and included presumably healthy preschool Cuban children (aged 6-59 months). Serum samples were collected from 1375 children from randomly selected provinces in 4 regions of the country from 2014 through 2018. We examined the association between ferritin and two inflammatory biomarkers: C-reactive protein and a1-acid glycoprotein. Individual inflammation-adjusted ferritin concentrations were calculated using four approaches: 1) a higher ferritin cut-off point (⟨30 g/L); 2) exclusion of subjects showing inflammation (C-reactive protein ⟩5 mg/L or a1-acid glycoprotein ⟩1 g/L); 3) mathematical correction factor based on C-reactive protein or a1-acid glycoprotein; and 4) correction by regression with the method proposed by the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia Group. We estimated confidence intervals of differences between unadjusted prevalence and prevalence adjusted for inflammation by each method. RESULTS: The proportion of children with inflammation according to C-reactive protein concentrations >5 mg/L was lower (11.1%, 153/1375) than the proportion measured according to the concentrations of a1-acid glycoprotein, at >1 g/L (30.8%, 424/1375). The percentage of children with high concentrations of at least one of the aforementioned biomarkers was 32.7% (450/1375). Thus, each correction method increased the observed prevalence of iron deficiency compared to unadjusted estimates (23%, 316/1375). This increase was more pronounced when using the internal regression correction method (based only on C-reactive protein) or the method based on a higher cut-off point. Adjustment using all four methods changed estimated iron deficiency prevalence, increasing it from 0.1% to 8.8%, compared to unadjusted values. CONCLUSIONS: One-third of preschool children had biomarkers indicating elevated inflammation levels. Without adjusting for inflammation, iron deficiency prevalence was underestimated. The significant disparity between unadjusted and inflammation-adjusted ferritin when using some approaches highlights the importance of selecting the right approach for accurate, corrected measurement. The internal regression correction approach is appropriate for epidemiological studies because it takes into account inflammation severity. However, other models should be explored that account for inflammation and also provide better adjusted ferritin concentrations.

Intervención nutricional participativa en adolescentes de enseñanza media del municipio Habana Vieja / Participative nutritional intervention in middle school adolescents from Habana Vieja municipality

Introducción: Los hábitos alimentarios no saludables potencian las enfermedades crónicas que constituyen las primeras causas de muerte en Cuba. Objetivos: Evaluar los efectos de una intervención nutricional sobre los cambios en los conocimientos de alimentación-nutrición y hábitos alimentarios en adolescentes. Métodos: Se realizó una intervención nutricional participativa con adolescentes de 12-15 años del municipio Habana Vieja, durante sus tres años curriculares. De los 604 adolescentes que comenzaron el estudio 155 formaron los grupos promotores que lideraron las actividades realizadas. Se aplicaron encuestas de conocimientos, consumo y hábitos alimentarios antes y después de la intervención. Para comparar la puntuación alcanzada se utilizó la prueba t de Student para muestras pareadas. Para la comparación entre escuelas se utilizó análisis de la varianza simple y para comparar los porcentajes de respuestas correctas de las preguntas de conocimientos, consumo de hortalizas y azúcar antes y después de la prueba de estimación de diferencias entre proporciones. Se definió como umbral de significación estadística p < 0,05. Resultados: Los grupos promotores mostraron aumentos significativos de los conocimientos (p < 0,001). Se encontraron diferencias entre escuelas para los grupos promotores (p < 0,001) y para el resto de los estudiantes (p = 0,024). Decreció el azúcar añadido a los refrescos para los grupos promotores (p < 0,001) y a la leche para todos los adolescentes (p = 0,002). No hubo cambios en el hábito de desayunar, en el gusto por alimentos fritos, ni en el consumo de refrescos, frituras, dulces y pizzas. Conclusiones: Las intervenciones de educación nutricional son necesarias para alcanzar patrones dietéticos más saludables y de esta manera contribuir a detener la epidemia de enfermedades no transmisibles, además permiten que los adolescentes tengan un acercamiento al tema alimentación-nutrición(AU)

Introduction: Non-healthy food habits boost chronic diseases that represent the main death causes in Cuba. Objectives: To assess the effects of a nutritional intervention on the changes in the knowledge of diet-nutrition and food habits of adolescents. Methods: It was carried out a participative nutritional intervention with adolescents from 12 to 15 years from Habana Vieja municipality during their 3 middle school years. From 604 adolescents that started the study, 155 formed the promoter groups which leadered the activities implemented. There were applied knowledge surveys on food consumption and habits before and after the intervention. For comparing the scores, it was used t-Student test for paired samples. It was used the analysis of simple variance for comparing among schools and the percentages of right answers in the knowledge questions, intake of vegetables and sugar before and after of the test for the estimation of differences among proportions. It was defined p<0,05 as the threshold of statistical signification. Results: The promoter groups showed significative increase of knowledge (p<0,001). There were found differences among schools for promoter groups (p<0,001) and for the rest of the students (p<0,024). In the promoter groups decreased the intake of sugar added to soft drinks (p<0,001) and to milk for all the adolescents studied (p<0,002). There were no changes in breakfast habits, liking fried food, or the consumption of soft drinks, fritters, sweets and pizzas. Conclusions: Nutritional education interventions are needed to reach healthier diet patterns and in this way contributing to stop the epidemic of non-communicable diseases; in addition, they allow adolescents to have an approach to food-nutrition topic(AU)

El bajo consumo de alimentos ricos en hierro y potenciadores de su absorción se asocia con anemia en preescolares cubanos de las provincias orientales: 2005-2011 / Low consumption of iron-containing foods and enhancer of iron absorption are associated with anemia in preschool children of the eastern provinces of Cuba: 2005-2011

Anemia in children less than five years of age is the main nutritional problem in Cuba. The aim of this study was to assess the intake of iron-rich foods (IRF) and of enhancers of iron absorption (EIA) in children living in the five eastern provinces of Cuba and its association with anemia in 2005, 2008 and 2011. A food frequency questionnaire of 6 months and hemoglobin determination were used. Intake increased in red meat and poultry (44.2% to 60.4%), eggs (38.7% to 58.6%) and vegetables (47.6% to 56.2%); decreased in fruit (73.2% to 55.8%) and legumes (87.7% to 57.7%). The prevalence of anemia in children 6 to 11 months old showed a decrease (62.1% to 44.3%). A reduction in the prevalence of anemia in infants 12-23 months old was found in 2008 compared with 2005 and reversed slightly in 2011, a similar finding was observed in children 2-5 years old. There was a consistent association of anemia with low intake of eggs, vegetables and fruits, but and not with low intake of legumes. Children who attended daycare center ate more iron-rich foods and enhancers of iron absorption than those who did not. The group of children younger than 24 months old remains the most vulnerable group for anemia.

La anemia en niños menores de 5 años constituye el principal problema nutricional en Cuba. El objetivo de este estudio fue estimar el consumo de alimentos ricos en hierro y potenciadores de su absorción en niños residentes en las cinco provincias orientales de Cuba y la asociación con la anemia en los años 2005, 2008 y 2011. La evaluación se realizó mediante una encuesta de frecuencia de consumo de alimentos en el período de 6 meses anterior a la fecha del estudio y determinación de hemoglobina mediante HemoCue. El consumo frecuente entre 2005 a 2011 incrementó en cárnicos (44.2% a 60.4%), huevos (38.7% a 58.6%) y vegetales (47.6% a 56.2%); con un descenso en frutas (73.2% a 55.8%) y leguminosas (87.7% a 57.7%). La prevalencia de anemia disminuyó en niños de 6 a 11 meses de 2005 a 2011 (62.1% a 44.3%). Se observó disminución de la anemia en el grupo de 12 a 23 meses en 2008 que revierte ligeramente el 2011, de manera similar ocurrió en el grupo de 24 a 59 meses. Se encontró asociación de la anemia con el bajo consumo de huevo, vegetales y frutas; no con el consumo de leguminosas. Los niños que asisten a guardería consumían alimentos ricos en hierro y potenciadores de su absorción con mayor frecuencia que los que no asistían, por lo que la asistencia a guardería constituye un factor protector para la anemia en esta población. El grupo de niños menores de 24 meses se mantiene como el grupo de mayor vulnerabilidad para la anemia.

Progreso en la reducción de la anemia en niños y niñas de un año de edad en La Habana entre los años 2005 y 2007 / Progress in the reduction of anemia in one year old childrens in La Havana from 2005 to 2007

Introducción: Los lactantes menores de 6 meses que no reciben lactancia materna exclusiva, y a partir de los 6 hasta los 12 meses de edad, constituyen los grupos con mayor riesgo de padecer anemia. Existen en Cuba actualmente múltiples programas como parte del Plan Integral para la prevención y el control de la anemia por deficiencia de hierro. La última estrategia que se implementó en el país fue la leche evaporada fortificada con hierro y zinc que se destina a todos los lactantes a partir del último trimestre del año 2005. Objetivo: Evaluar el estado nutricional del hierro en un grupo de niños y niñas de un año de edad mediante indicadores hematológicos y bioquímicos en dos períodos de tiempo. Métodos: Se realizó un estudio transversal en los años 2005 y 2007 en niños supuestamente sanos entre 10-14 meses, de ambos sexos de tres municipios de Ciudad de la Habana. Se realizaron determinaciones de hemoglobina (Hb), volumen corpuscular medio (VCM) e índice de distribución de eritrocitos (IDE) mediante contador hematológico automatizado; e indicadores bioquímicos de deficiencia de hierro: ferritina (FS), proteína C reactiva (PCR), receptores de Trans ferrina (sTfR) y zinc protoporfirina (ZPP). Se realizó una encuesta epidemiológica, evaluación antropométrica y dietética. La base de datos bioquímica, antropométrica, dietética y epidemiológica se preparó en el paquete estadístico SPSS 10.0; se realizó la evaluación de diferencia de proporciones, la evaluación de la adecuación de la ingestión de nutrientes y la comparación de los resultados por Chi-cuadrado con un 95% de intervalo de confianza. Resultados y Discusión: La prevalencia de anemia en el año 2007 (29.1%) fue menor que en 2005 (44.8%). En la última etapa se encontraron valores superiores de Hb y VCM e inferiores de IDE. La deficiencia de hierro fue alta en ambas etapas sin diferencias significativas. No se registraron niños con desnutrición en el estudio, pero sí hubo un mayor desbalance y dispersión de la muestra con relación a la clasificación normal de peso para la talla, con mayor cantidad de niños delgados, sobrepeso y obesos en la última etapa. Se incrementó el número de niños con ingestión adecuada de hierro en un 8.5 % pero la dieta no cubrió todas las necesidades nutricionales. Conclusiones: Se encontró una reducción de un 15,7% de la prevalencia de la anemia en niños de 10 a 14 meses de edad; y una mejoría de los indicadores hematológicos de deficiencia de hierro (VCM e IDE). Sin embargo las reservas de hierro (FS) continuaron deficientes (AU)

Introduction: Infants under 6 months are the main risk groups of anemia. Multiple programs for prevention and control of anemia are developing in Cuba, the last one is evaporated milk fortified with iron and zinc for infants. Objetive: To assess the nutritional status of iron in a group of children one year old using hematological and biochemical indicators in two periods of time. Methods: A cross-sectional study were conducted in 2005 and 2007 in apparently healthy children aged 10- 14 months old, both sexes from three municipalities in Havana. The hemoglobin (Hb), mean corpuscular volume (MCV) and red cell distribution width (RDW) by automated hematologic counter, and biochemical indicators of iron deficiency, ferritin (SF), C reactive protein (CRP), transferrin receptors (sTfR) and zinc protoporphyrin (ZPP) were measured. An epidemiological survey, anthropometric and dietary assessment was conducted. Biochemical, anthropometric, dietary and epidemiological database were prepared in SPSS 10.0. Difference of proportions, evaluation of adequacy of nutrient intake and comparison of iron results by Chisquare with 95% confidence interval was assessed. Results and Discussion: Anemia prevalence was lower in 2007 (29.1%) related to 2005 (44.8%). In the final stage Hb and MCV were higher and RDW were lower. Iron deficiency was high in both stages, with no significant differences. No malnourished children were founded but a greater imbalance and dispersion of the sample exist compared to the normal classification of weight for height; the amount of the children thin, overweight and obese increase in 2007 related to 2005. The percentage of infants with adequate iron intake increased (8.5%) but the diet did not cover all the nutritional needs of children. Conclusions: The15.7% of reduction the anemia prevalence in children 10 to 14 months old and improvement of hematological indicators of iron deficiency (MCV and RDW) was founded in second stage; however, iron stores (FS) are depleted (AU)

Hábitos, actitudes y preferencias alimentarias en adolescentes de enseñanza media de La Habana / Food habits, attitudes and preferentes in Secondary School adolescents in Havana

Fundamento y objetivo: Evaluar hábitos, gustos y preferencias relacionados con la alimentación y la nutrición de las escolares de enseñanza secundaria como diagnóstico previo a una intervención nutricional. Métodos: Se realizó un estudio descriptivo transversal en el universo de adolescentes de 7mo grado de 4 Secundarias Básicas del municipio Habana Vieja, en La Habana en el curso escolar 2004-2005. Participaron, deforma voluntaria 604 estudiantes de 12 años, 290 varones y 314 mujeres. Se recogió información sobre frecuencia de consumo de alimentos, hábitos, gustos y preferencias alimentarias por medio de cuestionarios confeccionados previamente validados. Resultados: El 52,3% de los varones y el 45,0% de las mujeres completaron de 5 a 6 comidas al día. Las raciones ausentes con mayor frecuencia fueron los desayunos y las meriendas En el patrón de consumo destacó el elevado consumo de azúcar, dulces; refrescos y algo menor de plzzas y otros alimentos callejeros y el poco variado consumo de hortalizas Se observó un bajo consumo de alimentos lácteos. Como buenos hábitos alimentarios se puede referir el consumo tradicional de frijoles, de condimentos naturales (cebolla, ajo, tomate y ají) y de aceite vegetal en prioridad a la manteca de cerdo. Los refrescos, dulces, pizzas, fritos y helados, de elevado contenido de azúcares y grasas saturadas quedaron entre los de mayor preferencia de los adolescentes También manifestaron una alta preferencia por jamón, carnes rojas, embutidos y queso. Las frutas y las hortalizas fueron menos deseadas. Conclusiones: A partir de los resultados obtenidos las acciones educativas deberán estar dirigidas a ampliar el espectro del consumo de hortalizas, disminuir el de azúcar, y enseñar a preparar alimentos en otras formas que no correspondan a "fritos" En cuanto a hábitos positivos se deberá reafirmar el consumo de frijoles como fuente de proteínas y hierro y el uso de condimentos naturales como cebolla, ajo y tomate, así como el de aceltes vegetales en lugar de la manteca de cerdo(AU)

Background and objective: To assess food habits, and preferences in Secondary in Secondary School adolescents as part of the diagnosis before a nutrition intervention. Methods: A desdriptive cross-sectional study was conducted on a convenience simple of 7th grade students in 4 secondary school in Habana Vieja district in the city of Havana during school year 2004-2005. Some 604 students aged 12 yr. Were recruited to participate in the study, 290 males and 314 females. Food consumption was assessed by means of a food frequency questionnaire. Information related to food habits and preferences was collected by specific validated questionnaires. Results: 52.3% of males and 45.0% of females consumed 5 to 6 meals a day. Breakfast and afternoon snacks were the meals missing more often. The average food pattern was characterized by a high consumption sugar, sweets, soft drinks and to a lesser extent pizza and other street food items. A poor variety in vegetables consumed and low consumption of milk and dairy products was also identified. The maintenance of the traditional consumption of pulses such as “frijoles” and natural seasonings such as onion, garlic or tomato as well as vegetable oir are highlighted on the positive side. Soft drinks, sweets, pizza, fried foods and ice cream, all food stuffs rich in sugar or saturated fat, were the preferred food items. A poor variety in vegetables consumed and low consumption of milk and dairy products was also identified. The maintenance of the traditional consumption of pulses such as “frijoles” and natural seasoning such as onion, garlic or tomato as well as vegetables oil are highlighted on the positive side. Soft drinks, sweets, pizza, fried foods and ice cream, all food items. Ham, red meat, sausages and cheese also scored high. Fruit and vegetables were the least liked. Conclusions: Based on the results, nutrition education actions should be addressed to widen the variety of vegetables consumed, to reduce consumption of sugar rich foods, and develop food preparation skills other than frying foods. On the positive side, consumption of pulses and use of natural seasoning like onion, garlic, tomato and vegetable oil should be reinforce(AU)

Progreso en el estado nutricional del yodo en Cuba / Progress in Iodine nutritional status in Cuba

Fundamentos y objetivos: Desde 1999 en Cuba se fortifica toda la sal de consumo humano con yodo. En el 2004 se realizo una evaluación de la excreción urinaria de yodo (EUY) como indicador de impacto del Programa de Yodación de la sal. Método: Para dar cumplimiento a este objetivo se determino la EUY en 1988 niños escolares de uno y otro sexo, de 6-12 años de edad representativos de los estratos urbano, rural y rural - montañoso de todo el país. Se recolectaron 1598 muestras de sal de los hogares de estos niños en las cuales se determinó la concentración de yodo mediante un test de detección rápida. Resultados: La mediana de EUY fue de 246,9 ug/L y se encontró un valor significativa mente menor en el estrato rural- montaña. El 66, 7% de las muestras de sal procedentes de los hogares mostraron niveles óptimos de yodación. Conclusiones: El resultado de la yoduria, principal indicador de impacto, muestra un estado nutricional de yodo óptimo tanto a nivel de país como de los diferentes estratos (AU)

Background and objectives: Since 1999 salt for human consumption is fortified with iodine in Cuba. In 2004 the fortification program was evaluated by measuring urine iodine excretion (EUY) as an indicator of the impact of the Iodinc Fortification Programo. Methods: EUY was measured in 1988 school children, boys and girls, aged 6-12 years. A random stratified sample representative for urban, rural and rural-mountain population was selected. 598 salt samples were collected at the participants households. Salt iodine content was assessed by a rapid detection test. Results: Median EUY was 246,9 ,ug/L and it was significantly lower in the rural-mountain popuJation. 66,7% of salt samples showed optimal iodine content. Conclusions: Urine iodine content showed an optimal iodine nutritional status both at the national level and at the different subpopulations (AU)

[The influence of calcium and phosphorus intake on bone mineral density in young women]. / Influencia de la ingesta de calcio y fósforo sobre la densidad mineral ósea en mujeres jóvenes.

The threat of osteoporosis in later life means that the bone mass women achieve during their youth is important. Eighty seven women aged 18-35 y from the Madrid region were studied to determine the relationship between their calcium, phosphorus and milk product intakes and bone mineral density (BMD). Intakes of these items were moniroed using a three day food intake record. BMD was measured by double photonic densitometry of the lumbar region, hip and right forearm. Mean calcium intake (802.1+/-258.7 mg/day) was less than that recommended for 45% of women. A linear, positive correlation was seen between calcium intake and BMD at the hip (r=0.23) and greater trochanter (r=0.24) (p<0.05). Women whose calcium intake was >1000 mg/day had greater hip BMDs than those whose intake was below this level (0.97+/-0.11 g/cm2 compared to 0.90+/-0.10 g/cm2). Similar results were seen for the femur head and greater trochanter in subjects whose Ca/P ratio was >0.74 (50th percentile). In addition, an intake of more than two rations of milk per day was optimum for achieving adequate bone mass in different areas of the hip. These results show that greater calcium consumption and a Ca/P ratio of >0.74 are associated with better BMD values in young women, and that milk is the lactic product best associated with good bone health.

Influencia de la ingesta de calcio y fósforo sobre la densidad mineral ósea en mujeres jóvenes / The influence of calcium and phosphorus intake on bone mineral density in young women

La masa ósea alcanzada durante la juventud en la población femenina resulta importante por la mayor susceptibilidad de este grupo de población de padecer osteoporosis. Con el objeto de conocer la relación entre ingesta de calcio, fósforo y productos lácteos y la densidad mineral ósea (DMO) se estudiaron 87 mujeres de la Comunidad de Madrid con edades comprendidas entre los 18 y 35 años. El consumo de lácteos y la ingesta de calcio y fósforo se valoró aplicando un Cuestionario de Registro de Consumo de Alimentos durante 3 días. La DMO se determinó mediante densitometría fotónica doble en la zona lumbar, cadera y antebrazo derecho. La ingesta media de calcio (802.1±258.7 mg/día) resultó inferior a la recomendada en el 45 por ciento de las mujeres; observándose una correlación lineal positiva entre consumo de calcio y DMO en cuello femoral (r=0.23) y trocánter mayor (r=0.24) (p<0.05). Las mujeres con ingesta de calcio superior a 1000 mg/día tuvieron mayor DMO en cadera (0.97±0.11 g/cm²) respecto a aquellas con ingesta inferior (0.90±0.10 g/cm²). Resultados similares se encontraron en cuello femoral y trocánter mayor en el grupo con una relación Ca/P superior a 0.74 (Percentil 50). Además, un consumo superior a dos raciones de leche diarias resultó óptimo para la adquisición de una adecuada masa ósea en diferentes zonas de la cadera. Estos resultados indican que un mayor consumo de calcio y una relación Ca/P > 0.74 están relacionados con una mejor DMO en mujeres jóvenes; siendo la leche el producto lácteo que presenta una mayor asociación con la salud ósea

Funciones de la vitamina c en el metabolismo del colágeno / Functions of vitamin C in the collagen metabolism

La mayoría de los mamíferos son capaces de sintetizar vitamina C, pero algunas especies como el hombre son dependientes de fuentes exógenas de esta vitamina porque carecen de la última enzima en la biosíntesis del ácido ascórbico a partir de la glucosa. Su principal función es como agente reductor en diferentes reacciones en el metabolismo del colágeno. Su deficiencia se asocia fundamentalmente con una disminución en la síntesis de procolágeno y con una reducida hidroxilación de los residuos prolina y lisina, obteniéndose una molécula menos estable a la temperatura corporal. En animales de laboratorio con carencia de esta vitamina se observó una disminución en la formación de residuos hidroxilisina en hueso, y por tanto, una reducción en la proporción pyridinolina (Pyd)/deoxypyridinolina (Dpd) en hueso y orina. Recientemente se han encontrado afectaciones similares en humanos (AU)

Funciones de la vitamina c en el metabolismo del colágeno / Functions of vitamin C in the collagen metabolism

La mayoría de los mamíferos son capaces de sintetizar vitamina C, pero algunas especies como el hombre son dependientes de fuentes exógenas de esta vitamina porque carecen de la última enzima en la biosíntesis del ácido ascórbico a partir de la glucosa. Su principal función es como agente reductor en diferentes reacciones en el metabolismo del colágeno. Su deficiencia se asocia fundamentalmente con una disminución en la síntesis de procolágeno y con una reducida hidroxilación de los residuos prolina y lisina, obteniéndose una molécula menos estable a la temperatura corporal. En animales de laboratorio con carencia de esta vitamina se observó una disminución en la formación de residuos hidroxilisina en hueso, y por tanto, una reducción en la proporción pyridinolina (Pyd)/deoxypyridinolina (Dpd) en hueso y orina. Recientemente se han encontrado afectaciones similares en humanos