Absorción mineral y retención ósea en ratas normales en crecimiento por el consumo de un yogur experimental reducido en lactosa que contiene galactooligosacáridos (GOS) / Mineral absorption and bone retention in normal growing rats by consumption of an experimental lactose-reduced yogurt containing galactooligosaccharides (GOS)

Introducción: Los GOS son prebióticos naturales presentes en la leche materna que pue-den obtenerse enzimáticamente a partir de la lactosa de leche de vaca durante la fabricación de yogur. El producto lácteo resultante será reducido en lactosa y contendrá prebióticos y bacterias potencialmente probióticas. Sin embargo, mantendrá la baja relación Ca/Pi que aporta la leche de vaca, lo que podría alterar el remodelamiento óseo y la mineralización. Objetivo: comparar si un yogur reducido en lactosa que contiene GOS (YE) ofrece ventajas adicionales respecto de un yogur regular sin GOS (YR) sobre las absorciones (Abs) de Ca y Pi, retención y calidad ósea durante el crecimiento normal. Al destete, ratas machos fueron divididas en 3 grupos alimentados con AIN ́93-G (C), YE o YR durante 28 días. Resultados: YE mostró el mayor aumento de lactobacilos fecales; producción de ácidos grasos de cadena corta especialmente p, profundidad de las criptas colónicas y menor pH cecal. El %AbsCa y %AbsPi aumentó en el siguiente órden: YE> YR> C (p < 0,05). El contenido de Ca y Pi en fémur, la densidad y contenido mineral óseos y los parámetros biomecánicos fueron similares en YE y C, mientras que YR mostró valores significativa-mente menores (p < 0,05). Conclusiones: YE aumentó las Abs y biodisponibilidad de minerales, alcanzando la retención y calidad ósea de C. El aumento en las Abs observado en YR no logró obtener la retención y calidad ósea de C. Conclusión: YE habría contrarrestado el efecto negativo del mayor aporte de Pi de la leche de vaca y sería una buena estrategia para lograr el pico de masa ósea y calidad del hueso adecuados, especialmente en individuos intolerantes a la lactosa. (AU)

Breast milk contains an optimal calcium/phosphate (Ca/Pi) ratio and GOS. These natural prebiotics can be enzymatically produced via cow's milk lactose inyogurt manufacture. This milk product is low in lactose and contains prebiotics and potentially probiotic bacteria but maintains a low Ca/Pi ratio that could alter bone remodeling and mineralization. We evaluated if a lactose-reduced yogurt containing GOS (YE) offers additional advantages over regular yogurt without GOS (YR) on Ca and Pi absorption (Abs), bone retention and quality during normal growth. Weaning male rats were divided into 3 groups fed AIN'93-G (C), YE or YR for 28 days. Results: YE showed the highest increase in fecal lactobacilli; short-chain fatty acids production, especially propionate and butyrate; intestine crypt depth, and the lowest cecal pH. AbsCa% and AbsPi% increased in this order: YE> YR> C (p <0.05). Ca and Pi content in femur, bone density and mineral content, and biomechanical parameters were similar in YE and C, while YR showed the significantly lowest value (p < 0.05). Conclusions: YE increased mineral Abs reaching the retention and bone quality of C. Although YR increased Abs, bone retention and quality did not achieve C values. Seemingly, YE compensated for the negative effect of the higher Pi supply and would be a good strategy to achieve adequate peak bone mass and bone quality, especially in lactose intolerant individuals. (AU)

Changes in energetic metabolism of Biomphalaria glabrata (Mollusca, Planorbidae) in response to exogenous calcium / Alterações no metabolismo energético de Biomphalaria glabrata em resposta ao cálcio exógeno

Abstract Calcium is considered an essential element for the metabolism of aquatic snail Biomphalaria glabrata (Say, 1818), intermediate host of Schistosoma mansoni Sambon, 1907 in Brazil, and represents a limiting factor to its distribution and adaptation to the environment. This study investigated the effect of different concentrations of exogenous CaCO3 on the energetic metabolism of B. glabrata for better understanding the physiological interference of chemical elements dissolved in the environment with the physiology of this species. Sixty-day-old snails were distributed into six groups, five exposed to different concentrations of CaCO3 (20, 40, 60, 80 and 100 mg/L) and a control group. The exposure to CaCO3 was assessed over time, with analysis of 15 snails of each group in the following intervals: 1, 14, 21 or 30 days for hemolymph extraction. Concentrations of calcium and glucose in the hemolymph were determined by commercial kits, and organic acids were extracted using an ion exchange column and analyzed by high-performance liquid chromatography. Concentration of calcium in the hemolymph showed no significant difference (p>0.05) from the control group and between the concentrations tested. Concentration of glucose decreased (p<0.05) in the treatments of exposure to 20 and 40 mg/L and increased when exposed to 80 and 100 mg/L CaCO3 compared to control and to other concentrations tested over 30 days. The organic acids pyruvate, oxaloacetate, citrate, succinate, fumarate, beta-hydroxybutyrate and lactate presented increased concentrations, while propionate and acetoacetate, decreased concentrations, when exposed to CaCO3 compared to control. Considering the influence of different periods of exposure to CaCO3, on the 14th day, there were stronger alterations in the metabolism of B. glabrata. In conclusion, exposure to CaCO3 reduced the concentration of glucose, which is metabolized into pyruvate, the final product of glycolysis, and also influenced the energetic metabolism pathways, indicating an aerobic or partially anaerobic functioning.

Resumo O cálcio é considerado um elemento essencial no metabolismo do molusco aquático Biomphalaria glabrata (Say, 1818), principal hospedeiro intermediário de Schistosoma mansoni Sambon, 1907 no Brasil e, tem sido descrito como um fator limitante na distribuição e adaptação desse molusco no ambiente. O presente trabalho avaliou o efeito de diferentes concentrações de carbonato de cálcio (CaCO3) exógeno ao metabolismo energético de B. glabrata, a fim de subsidiar uma melhor compreensão da interferência de elementos químicos dissolvidos no meio aquático na fisiologia destes moluscos. Foram utilizados moluscos com sessenta dias de vida, distribuídos em seis grupos, cinco expostos a diferentes concentrações de CaCO3 (20, 40, 60, 80 e 100mg/L) e um controle. A exposição ao CaCO3 foi avaliada em função do tempo, sendo retirados 15 moluscos de cada grupo nos seguintes intervalos: 1, 14, 21 ou 30 dias para extração da hemolinfa. As concentrações de cálcio e glicose na hemolinfa foram determinadas usando-se kits comercial e os ácidos orgânicos foram extraídos por meio da coluna de troca iônica e analisados através cromatografia líquida de alta eficiência. Os resultados demonstraram que a concentração de cálcio na hemolinfa não apresentou diferença significativa (p>0,05) em relação ao controle e nas concentrações testadas. A concentração de glicose diminuiu (p<0,05) nas exposições a 20 mg e 40 mg/L e aumentou nas exposições a 80 mg e 100 mg/L de CaCO3 em relação ao controle e demais concentrações testadas ao longo de 30 dias. Os ácidos orgânicos piruvato, oxaloaceato, citrato, succinato, fumarato, β-hidroxibutirato e lactato tiveram suas concentrações aumentadas, enqunato, propionato e acetoacetato tiveram suas concentrações diminuídas na exposição ao CaCO3 comparada ao controle. Quanto a influência dos diferentes períodos de exposição ao CaCO3, aos 14 dias, as alterações no metabolismo de B. glabrata foram mais expressivas. Conclui-se que as exposições ao CaCO3 influenciaram na redução de glicose, sendo esta metabolizada a piruvato, produto final da glicólise e alteraram as vias de metabolismo energético, indicando um funcionamento aeróbio ou parcialmente anaeróbio.

Ingestión de calcio y adiposidad en adolescentes de 12 a 16 años en Guadalajara, México / Calcium intake and adiposity in adolescents aged 12- 16 years in Guadalajara, Mexico

El objetivo del trabajo fue evaluar la asociación entre el consumo de calcio (Ca) y adiposidad en un grupo de adolescentes. Se realizó un estudio transversal en 125 adolescentes de 12 a 16 años. El consumo de Ca se evaluó por encuestas alimentarias de recordatorio de 24 horas y frecuencia de consumo de alimentos. Se midió la adiposidad por métodos antropométricos e impedancia bioeléctrica (IBE). Se identificó la relación entre el consumo de Ca y adiposidad mediante correlación simple; se realizaron modelos multivariados ajustados al consumo de energía, edad, sexo y menarquía. El promedio de edad fue de 13.5 ± 0.8 años. Se identificó correlación negativa entre el consumo de Ca y los indicadores antropométricos peso, pliegues cutáneos, índice de masa corporal, masa grasa y porcentaje de grasa (los dos últimos por IBE y solamente en mujeres). El análisis multivariado, que incluyó el consumo de energía, no demostró asociación entre el consumo de Ca y adiposidad. En conclusión, el consumo de Ca no se asocia a adiposidad en adolescentes; los modelos multivariados mostraron que el consumo total de energía y la menarquía son las variables que muestran mayor asociación con adiposidad en esta etapa de la vida.

The purpose was to evaluate the association between calcium (Ca) intake and adiposity in adolescents. A cross-sectional study of 125 adolescents 12 to 16 years. Ca intake was evaluated by 24-hour recall dietary surveys and food frequency consumption. Adiposity was measured by anthropometric methods and bioelectrical impedance (BIA). The association between Ca intake and adiposity was identified by simple correlation and multivariate models adjusted to energy consumption, age, sex and menarche. Mean age of adolescents was 13.5 ± 0.8 years. A negative correlation was identified between Ca intake and anthropometric indicators weight, skinfolds, body mass index, fat mass and percentage of fat (the latter two by BIA and only in women). Multivariate analysis, including energy consumption showed no association between Ca intake and adiposity. In conclusion, Ca consumption does not associate with adiposity in adolescents; multivariate models showed that energy intake and menarche are the variables that show a higher association with adiposity at this stage of life.

Frutanos do tipo inulina e aumento da absorção de cálcio: uma revisão sistemática / Inulin-type fructans and calcium absorption enhancement: a systematic review

Realizou-se uma revisão sistemática da literatura sobre os efeitos do consumo de frutanos do tipo inulina na absorção de cálcio. Resultados de quatro dos sete ensaios clínicos duplo-cegos controlados aleatorizados relatados neste trabalho indicam que o consumo diário da mistura de frutanos (inulina e oligofrutose 1:1) aumenta a absorção de cálcio, dependendo da idade cronológica e fisiológica, bem como do estado menopausal de indivíduos saudáveis que consomem quantidades adequadas de cálcio. O número limitado de ensaios clínicos realizados e as diferenças relativas ao planejamento experimental, tempo de estudo, tipo e quantidade de frutano consumido (inulina, oligofrutose ou a mistura de ambos), bem como a faixa etária dos indivíduos, impedem a generalização dos resultados observados. Esta revisão demonstra a necessidade de mais ensaios clínicos de longa duração, nos quais tanto a absorção de cálcio como a densidade mineral óssea sejam avaliadas. Futuros estudos devem contribuir para a compreensão dos mecanismos de ação dos frutanos no aumento da absorção de cálcio; para avaliar se esse efeito persiste em longo prazo e se pode ser considerado como benefício real para a saúde óssea; e para testar se tais efeitos poderiam beneficiar indivíduos de outras faixas etárias e diferentes condições fisiológicas. Evidências científicas consistentes e acumuladas ainda são necessárias para poder considerar o consumo de frutanos como uma estratégia de prevenção da osteoporose.

We performed a systematic review of literature regarding the effects of inulin-type fructans consumption on calcium absorption. Results of four from seven double-blind randomized controlled clinical trials revised in this work showed that daily consumption of fructans mixture (inulin and oligofructose 1:1) increases calcium absorption, depending on the chronological and physiological age, and menopausal status of healthy individuals who consume adequate amounts of calcium. Due to the limited number of clinical trials and the differences on the experimental design, follow-up, fructans type (inulin, oligofructose or their mixture) and quantity consumed, and the individuals' age, the results cannot be generalized. This review demonstrates the need for more long-term follow-up clinical trial, in which both calcium absorption and bone mineral density are measured. Further studies may help understand the mechanisms underlying the effects of inulin-type fructans on calcium absorption, and to evaluate if the increased calcium absorption is long-term persistence and if it can be translated into real benefits to bone health; and also to test whether these effects could benefit individuals with other age groups and in different physiological conditions. Consistent accumulated scientific evidences are still necessary to consider inulin-type fructans consumption as a prevention strategy for osteoporosis.

Infl uence of dietary calcium content on intestinal permeability in rat.

Background & objectives: Agents that increase the permeability of intestinal epithelium promote the absorption of nutrients by the gut. High calcium concentration in the gut has been shown to enhance passive transport of glucose in the rat intestine. An increase in the permeability of the intestinal epithelium may account for this observation. The present study was aimed at monitoring the permeability of intestine of rats fed high or low calcium diets. Methods: Everted intestinal sacs were used to study transports of substances across the gut. While radioactive and non radioactive calcium isotopes were employed to study the active transport and passive transport of calcium, transport of labelled mannitol was taken as a measure of passive permeability. Results: High calcium diet increased the passive transport of mannitol and calcium while decreasing the active transport of calcium by the everted gut sacs. Interpretation & conclusion: Passive mechanisms are enhanced by high calcium diet, while low calcium diet favours active transport. Calcium in the diet may be affecting intestinal transport.

Asymptomatic rickets in adolescent girls.

OBJECTIVE: Inadequate sunlight exposure and calcium intake during rapid growth at puberty lead to hypocalcemia, hypovitaminosis D and eventually to overt rickets. To determine serum biochemical findings of rickets in healthy 11-15 yr old girls, the effect of sunlight exposure and oral vitamin D supplementation on serum 25- hydroxy vitamin D and calcium administration in girls with abnormal findings during December 2002 through March 2003 in Tehran, Iran. METHODS: Healthy middle school girls were selected for estimation of vitamin D, calcium and phosphorus intake by a three-day food recall. And measurement of serum calcium, phosphorus, parathyroid hormone, alkaline-phosphatase and 25- hydroxyvitamin D concentration. The girls with abnormal findings divided in two groups. Hypovitaminosis D girls subdivided into two groups, supplementary sunlight exposure and vitamin- D administrated for them and calcium administration for the second group for 20 days. RESULTS: Of 414 girls, the mean daily vitamin D acquirement and calcium intake were 119 +/- 52 IU and 360 +/- 350 mg among all girls respectively. Mean serum 25-hydroxyvitamin D with two or more abnormal biochemical findings in 15 (3.6%) girls (group I) were 7.8 ng/ml and alkaline phosphatse with normal or low calcium in 29 (7%) girls (group II) was 1187 IU/L. Mean serum calcium was 8.2 mg % in 8 of 29 girls. Serum 25- hydroxyvitamin D before and after sunlight exposure was 7.1 +/- 1.9 ng/ml and 13.9 +/- 2.4 ng/ml and vitamin D administration was 7.4 +/- 1.8 ng/ml (group Ia) and 27.9 +/- 4.2 ng/ml (group Ib) respectively. Serum alkaline phosphatase before and after calcium administration were 1187 IU/L and 666 IU/L respectively. CONCLUSION: We conclude that low daily calcium intake and vitamin D acquirement are two important problems in Iranian girls during rapid growth at puberty; therefore, for prevention of overt rickets calcium and vitamin D Supplementation appear to be necessary.

Cinética do fósforo em tecidos de ovinos em crescimento alimentados com diferentes fontes de cálcio / Kinetics of phosphorus in tissues of lambs fed different sources of calcium

Foram utilizados 12 cordeiros machos, inteiros, com peso médio de 31,6kg. Os cordeiros foram alimentados com dietas à base de milho e farelo de soja, suplementadas com diferentes fontes de cálcio: calcário calcítico (CC), feno de alfafa (FA), polpa cítrica (PC) e farinha de conchas de ostras (FCO). Os animais receberam injeção de 7,4 MBq do radiofósforo (32P) e após sete dias foram abatidos para posteriores análises. Utilizou-se o delineamento em blocos ao acaso, com quatro tratamentos e três repetições. A taxa de retenção de 32P, as atividades específicas relativas e padronizadas, e a quantidade de P inorgânico nos tecidos foram iguais para todos os tratamentos (P>0,05). A comparação entre os tecidos mostrou que a concentração de P inorgânico e a taxa de retenção de 32P (P<0,01) foram mais altas nos ossos em relação aos tecidos moles (P<0,01). A retenção de 32P apresentou a seguinte ordem decrescente: rins, fígado, coração, músculos e ossos (P<0,01). A reabsorção óssea de P foi maior que a deposição de P, levando ao balanço negativo do elemento para a maioria dos animais. Concluiu-se que as diferentes fontes de cálcio não interferiram na cinética do P e que a quantidade de P ingerida não atendeu às exigências de P dos animais.

Sixteen growing rams, averaging 31.6kg were studied. They were fed diets based on corn and soya meal, supplemented with different sources of calcium: limestone (CC), alfalfa hay (FA), citrus pulp (PC) and oyster shell meal (OSM). The animals received an injection of 7.4 MBq of radioactive P (32P) and after 7 days they were slaughtered for further analyses. Experimental measurements were analyzed as a completely randomized design with four treatments and three repetitions. The rate of 32P retention, the relative specific activity, the standardized specific activity and the inorganic P in tissue were similar for all treatments (P>0.05). The comparison between tissues showed that the concentration of inorganic P and rate of 32P retention was greater in bone (P<0.01) than in soft tissue. The 32P retention presented the following decreasing order: kidney, liver, heart, muscle and bone (P<0.01). P resorption in bone was higher than P accreted in bone, leading to a negative balance of P in bone for the majority of animals. The means for P accreted in bone were 1.56, 3.29, 2.74 and 2.06g/animal and the means for P resorption in bone were 2.82, 4.51, 4.09 and 3.05g/animal for limestone (CC), alfalfa hay (FA), citrus pulp (PC) and oyster shell meal (OSM), respectively. P resorption values were higher than P accretion in bone leading to a negative balance of P for the majority of animals. It was concluded that the different sources of calcium did not interfere in the kinetics of phosphorus and the amount of P absorbed did not attend P demands of the animals.

Correlação entre a exposição ao chumbo e a atividade da enzima ácido d-aminolevulínico desidratase (ALA-D), paratormônio (PTH) e fatores nutricionais em crianças / Correlation between the exposition to the leads and the activity of the aminolevulinic acid enzyme dehydratase (ALA-D), (PTH) and nutritional factors in children

O percentual de recuperação da enzima Ácido d-Aminolevulínico Desidratase (ALA-D) é um indicador de efeito sensível e específico para toxicidade ao chumbo mesmo a baixos níveis de chumbo em sangue (Pb-S). Atualmente, a saúde das crianças expostas ambientalmente às substâncias tóxicas tem sido objeto de grande atenção. Muitos estudos têm encontrado uma associação inversa entre o Pb-S e o crescimento ósseo. A homeostasia do cálcio é regulada pela ação do paratormônio (PTH), da Vitamina D e da Calcitonina, podendo o chumbo afetar aspectos deste metabolismo. O objetivo deste estudo foi avaliar os efeitos do chumbo sobre o metabolismo ósseo em crianças de 0 a 16 anos através da determinação da ALA-D em sangue e correlacionar com os níveis de PTH e fatores nutricionais. Este estudo foi realizado na comunidade João Goulard, em Manguinhos, no Rio de Janeiro. As amostras biológicas foram coletadas no Laboratório do CSEGSF/ENSP, onde os questionários de freqüência alimentar e sócio-econômicos foram aplicados. A determinação da atividade enzimática da ALA-D e do PTH foram realizados por Espectrofotometria e quimioluminescência, respectivamente...

Cálcio e vitamina D: intervenções nutricionais na osteoporose / Calcium and vitamin D: nutritionals intervention on osteoporosis

Visto ser o cálcio de extrema importância na alimentação e na saúde para todas as faixas etárias, sua inadequação nutricional, aliada a outros fatores, culmina com o enfraquecimento da massa óssea e o desenvolvimento da osteoporose, levando à perda da autonomia e da qualidade de vida no decorrer do envelhecimento. Por estas razões, o planejamento e orientação dietética são condutas relevantes no controle e prevenção desta que é reconhecida como endemia oculta.

Balance de calcio y fósforo en mujeres lactantes rurales de México / Metabolic balance of calcium and phosphorus during lactation in mexican rural women

Objetivo. Comparar el balance metabólico de calcio y fósforo de lactancia versus el de destete, así como determinar la producción de calcio y fósforo en la leche de mujeres de una comunidad rural de México a diferentes tiempos de lactancia. Métodos. Se estudiaron 36 mujeres con edades entre 18 y 36 años, peso de 49 ñ 3 kg y talla de 148 ñ 2 cm, divididas en seis grupos: cuatro grupos de lactancia (1º, 3º, 12º mes), uno de destete y uno no lactantes. El balance metabólico fue diez días, con duplicados de la dieta, orina de 24 horas (3 días, heces de 72 horas y muestras de leche de 24 horas (2 días). Se determinó calcio (Ca) por espectrofotometría de absorción atómica y fosforo por método colorimétrico con molibdato-metavanadato. Resultados y conclusiones. Al tercer mes de lactancia se observó el mayor contenido de Ca en leche (246 mg/día). En la lactancia se observaron balances negativos de Ca(789 ñ 165 mg/día); en los primeros meses fue menor de excreción urinaria, lo que sugiere un mecanismo de conservación de Ca. no se observaron diferencias en el contenido de fósforo en leche. Los grupos de mujeres no lactantes y del destete presentaron balances positivos de fósforo, mientras que en la lactancia se observaron balances negativos (115 a 475 mg/día). La excreción fecal de Ca y fósforo fue salta (~1300 mg/día) lo que contribuyó a la condición negativa del babance. La producción de Ca y fósforo en leche fue similar a lo referido para poblaciones rurales y urbanas de Africa, Asia, Europea y Estados Unidos

Ingesta de calcio y densidad ósea mineral en la menopausia: datos de una muestra de mujeres chilenas seguidas durante cinco años con suplementación cálcica / Relationship between calcium intake and bone mineral density in menopausal women followed for five years with calcium supplementation

Background: A low calcium intake is considered a risk factor for osteoporosis. Aim: To measure calcium intake and its relationship to bone mineral density in postmenopausal women and to assess the long term changes in bone mineral density after calcium supplementation. Patients and methods: in 80 postmenopausal women older than 41 years of age, calcium intake was assessed using dietary inquires and bone mineral density was measured using a double beam radiological densitometer. Twenty-four ramdomly selected women received a daily calcium supplementation of 500 mg during five years and their bone mineral density was measured at 1,3 and 5 years. Results: Initial calcium intake was 745±37mg/day, and it did not change in the 5 years follow up. There was no relationship between bone mineral density and calcium intake. In supplemented women, bone density did not change significantly at year one. At year three, a significant reduction was observed in the spine (-4.2 percent), Wards triangle (-4 percent) and whole body mineral content(-1.14 percent). At year five, there was a significant increase in bone density at the spine femoral neck and Wards triangle as compared with year three, but not with baseline measurements. No significant differences after supplementation were observed between women with initial calcium intake of less than 500 mg/day or over this value. Conclusions: Calcium intake in urban Chilean postmenopausal women is below recommendations and stable over time. Calcium intake and bone mineral density after the meinopause are not correlated. A 500 mg/day calcium supplementation during 5 years is associated with a late reversal of the postmenopausal bone-losing trend

Suplementación dietetica con calcio en la hipertensión inducida por el embarazo

La hipertensión inducida por el embarazo constituye la primera causa de morbi-mortalidad materna en Ecuador. Su etiopatogenia continúa siendo controvertida, a pesar de que se ha demostrado de que se trata de un estado de deficiencia de prostaciclina. Observaciones epidemiológicas han llevado a proponer una relación entre ingesta de calcio e incidencia de la enfermedad. Nosotros hemos estudiado esta aparente relación inversa y hemos demostrado que la suplementación con calcio disminuye significantemente la incidencia de la enfermedad. Resultados experimentales nos han llevado a proponer que esta acción de la suplementación con calcio podría estar medida por estimulación de la síntesis vascular de prostaciclina