There is increasing epidemiologic and animal evidence that a low calcium diet increases blood pressure. The aim of this review is to compile the information on the link between low calcium intake and blood pressure. Calcium intake may regulate blood pressure by modifying intracellular calcium in vascular smooth muscle cells and by varying vascular volume through the renin–angiotensin–aldosterone system. Low calcium intake produces a rise of parathyroid gland activity. The parathyroid hormone increases intracellular calcium in vascular smooth muscles resulting in vasoconstriction. Parathyroidectomized animals did not show an increase in blood pressure when fed a low calcium diet as did sham-operated animals. Low calcium intake also increases the synthesis of calcitriol in a direct manner or mediated by parathyroid hormone (PTH). Calcitriol increases intracellular calcium in vascular smooth muscle cells. Both low calcium intake and PTH may stimulate renin release and consequently angiotensin II and aldosterone synthesis. We are willing with this review to promote discussions and contributions to achieve a better understanding of these mechanisms, and if required, the design of future studies.

Objective To describe the calcium concentration of tap and bottled waters from Argentina and to estimate the contribution of drinking water to calcium recommendations. Results Calcium concentrations provided by water authorities ranged from 6 to 105 mg/L. The mean calcium level of samples analysed at the Laboratorio de Ingeniería Sanitaria, National University of La Plata was 15.8 (SD ± 13.2) mg/L and at the Bone Biology Laboratory of the National University of Rosario was 13.1 (± 10.0) mg/L. Calcium values of samples from supply systems and private wells was similar. Most bottled waters had calcium levels well below 50 mg/L. The intake of one litre of drinking water from Argentina could represent in average between 1.2 and 8.0% of the calcium daily values for an adult.

Background: Food fortification is an effective strategy that has been recommended for improving population calcium inadequate intakes. Increasing calcium concentration of water has been proposed as a possible strategy to improve calcium intake. The objective of this study was to determine the sensory threshold of different calcium salts added to drinking water using survival analysis. Methods: We performed the triangle test methodology for samples of water with added calcium using three different calcium salts: calcium chloride, calcium gluconate and calcium lactate. For each salt, a panel of 54 consumers tested seven batches of three water samples. Data were adjusted for chance and sensory threshold was estimated using the survival methodology and a discrimination of 50%. Results: The threshold value estimation for calcium gluconate was 587 ± 131 mg/L of water, corresponding to 25% discrimination, for calcium lactate was 676 ± 186 mg/L, corresponding to 50% discrimination, and for calcium chloride was 291 ± 73 mg/L, corresponding to 50% discrimination. Conclusions: These results show that water with calcium added in different salts and up to a concentration of 500 mg of calcium/L of water is feasible. The calcium salt allowing the highest calcium concentration with the lowest perceived changes in taste was calcium gluconate. Future studies need to explore stability and acceptability over longer periods of time.

We present the results of a study of outdoor air quality in two comparable regions of Buenos Aires province (Argentina); La Plata and Bahía Blanca, developed jointly by researchers of the National University in both cities, and of the Hospital of Bahía Blanca, between 2009 and 2011. Both regions are characterized by a large petrochemical complex and a village with outstanding traffic. In this study, we measure levels of volatile organic compounds (VOCs), particulate matter suspended in air (PM) in air outdoor and affectation of respiratory system in children between 6 and 12 years. Also, analysis of the effect of the air pollution exposure was made through the calculation of potentially increased life time cancer risk (LCR) in children. In both regions, including three areas: urban, industrial and residential (reference area), 20 VOCs were sampled by passive monitoring (3M 3500), and determined by GC/FID, comprising n-alkanes, cycloalkanes, aromatics, chlorinated compounds, terpenoids and ketones; particulate matter (PM10) was token using a low flow sampler MiniVol TAS, and spirometry were performed, using a portable spirometer.The collected data show higher levels of PM10 in Bahía Blanca, both in the industrial zone and urban areas, the industrial area of Bahía Blanca with very bad air quality, associable with a 5% increase in mortality. The levels of total VOCs found in the residential area for both regions are comparable. Spirometry parameters of children living in an industrial area evidence respiratory disease with respect to urban and residential areas.

Background: Food fortification is an effective strategy that has been recommended for improving population calcium inadequate intakes. Increasing calcium concentration of water has been proposed as a possible strategy to improve calcium intake. The objective of this study was to determine the sensory threshold of different calcium salts added to drinking water using survival analysis. Methods: We performed the triangle test methodology for samples of water with added calcium using three different calcium salts: calcium chloride, calcium gluconate and calcium lactate. For each salt, a panel of 54 consumers tested seven batches of three water samples. Data were adjusted for chance and sensory threshold was estimated using the survival methodology and a discrimination of 50%. Results: The threshold value estimation for calcium gluconate was 587 ± 131 mg/L of water, corresponding to 25% discrimination, for calcium lactate was 676 ± 186 mg/L, corresponding to 50% discrimination, and for calcium chloride was 291 ± 73 mg/L, corresponding to 50% discrimination. Conclusions: These results show that water with calcium added in different salts and up to a concentration of 500 mg of calcium/L of water is feasible. The calcium salt allowing the highest calcium concentration with the lowest perceived changes in taste was calcium gluconate. Future studies need to explore stability and acceptability over longer periods of time.

Introduction. Vitamin A deficiency (VAD) has been recognized as an important public health problem in developing countries. Preschoolers account for risk groups within vulnerable populations. The objective of this study was to determine the prevalence of VAD and associated factors in a sample of preschoolers. Material and methods. Cross-sectional study with children aged 1-6 years receiving social assistance and seen at primary health care centers in the outskirts of the city of La Plata, Buenos Aires. Vitamin A levels were determined by measuring serum retinol with a liquid chromatography; anthropometric parameters and dietary intake were recorded. A multinomial logistic regression model was used to assess the association among outcome measures. Results. Data from 624 children were analyzed. The geometric mean of retinol was 23.8 μg/dL (95 % CI: 23.3-24.3). The prevalence of VAD and the risk for VAD were 24.3 % and 57.4 %, respectively. Retinol levels were significantly lower among boys, low-weight children, and those with low intake (below the first tertile of distribution). The multivariate analysis showed a significant association between VAD and male sex (odds ratio: 1.93; 95 % CI: 1.15-3.24) and between VAD and low intake (odds ratio: 1.48; 95 % CI: 1.15-2.62). Conclusion. The prevalence of VAD (24.3 %) is a major public health problem in this population. VAD-associated factors were male sex and low vitamin A intake.

Dietary calcium intake is low in many countries, particularly in low-and middle-income countries (LMICs). Water is often overlooked as a source of dietary calcium despite it being universally consumed and providing good calcium bioavailability. Our objective was to assess water distribution systems in LMICs and to develop a formula to simulate the contribution of different water sources to calcium availability. We calculated the contribution of drinking water considering different calcium concentration levels to estimate total calcium availability. We consider a country's households' access to drinking water sources and the distribution of the country's population by age and gender.Calcium availability could be increased by an average of 49 mg of calcium per person per day in the 62 countries assessed if calcium in drinking water was considered. In 22 (31%) of the countries studied, 80% of households are supplied by water sources that could increase calcium availability. Improving calcium concentration in water could be considered as a strategy in LMICs to slightly improve calcium availability.

Vitamin A content was not enough to satisfy the recommendations in half of the cases.