Empirically Fitted Parameters for Calculating pKa Values with Small Deviations from Experiments Using a Simple Computational Strategy.

Two empirically fitted parameters have been derived for 74 levels of theory. They allow fast and reliable pKa calculations using only the Gibbs energy difference between an acid and its conjugated base in aqueous solution (ΔGs(BA)). The parameters were obtained by least-squares fits of ΔGs(BA) vs experimental pKa values for phenols, carboxylic acids, and amines using training sets of 20 molecules for each chemical family. Test sets of 10 molecules per family-completely independent from the training set-were used to verify the reliability of the fitting parameters method. It was found that, except for MP2, deviations from experiments are lower than 0.5 pKa units. Moreover, mean unsigned errors lower than 0.35 pKa units were found for the 98.6%, 98.6%, and 94.6% of the tested levels of theory for phenols, carboxylic acids and amines, respectively. The parameters estimated here are expected to facilitate computationally based estimations of pKa values of species for which this magnitude is still unknown, with uncertainties similar to the experimental ones. However, the present study deals only with molecules of modest complexity, thus the reliability of the FP method for more complex systems remains to be tested.

Introduction: Prevalence of Micronutrient Deficiencies in Latin America and the Caribbean.

This Food and Nutrition Bulletin supplement summarizes updated prevalence data on micronutrient deficiencies in Latin America and the Caribbean (LAC). In order to provide an updated view of micronutrient status in LAC, systematic reviews were performed utilizing national health surveys and research-oriented studies focused on the prevalence of deficiencies of vitamin A, folate, anemia (as a proxy of iron deficiency), and zinc. Results show that the prevalence of vitamin A deficiency has been reduced in many countries, folate deficiency is now almost non-existent, low or marginal vitamin B12 status is still prevalent in most locations, anemia remains a public health problem among children under 6 years of age and women of childbearing age in most surveyed countries, and there is a high prevalence of zinc deficiency in children under 6 years of age and girls and women 12 to 49 years of age. Thus, regardless of improvements in the overall rates of economic growth in LAC, deficiencies of these micronutrients still remain a public health problem.

Zinc Deficiency in Latin America and the Caribbean.

BACKGROUND: Zinc deficiency affects multiple vital functions in the life cycle, especially growth. Limited information is available on the magnitude of zinc deficiency in Latin America and the Caribbean. OBJECTIVE: To examine the latest available information on both the prevalence of zinc deficiency and the risk of zinc deficiency in Latin America and the Caribbean. METHODS: The prevalence of zinc deficiency was identified through a systematic review looking for the latest available data on serum zinc concentrations from surveys or studies with national representativeness conducted in Latin America and the Caribbean. The risk of zinc deficiency in Latin America and the Caribbean was estimated based on dietary zinc inadequacy (according to the 2011 National Food Balance Sheets) and stunting in children under 5 years of age. RESULTS: Only four countries had available national biochemical data. Mexican, Colombian, Ecuadorian, and Guatemalan children under 6 years of age and women 12 to 49 years of age had a high prevalence of zinc deficiency (19.1% to 56.3%). The countries with the highest risk of zinc deficiency (estimated prevalence of inadequate zinc intake > 25% plus prevalence of stunting > 20%) were Belize, Bolivia, El Salvador, Guatemala, Haiti, Honduras, Nicaragua, and Saint Vincent and the Grenadines. Zinc dietary inadequacy was directly correlated with stunting (r = 0.64, p < .001). CONCLUSIONS: Prevalence data from the four available Latin America and Caribbean national surveys indicate a high prevalence of zinc deficiency in children under 6 years of age and women 12 to 49 years of age. High rates of both estimated zinc dietary inadequacy and stunting were also reported in most Latin America and Caribbean countries.

Prevalence of Anemia in Latin America and the Caribbean.

BACKGROUND: In Latin America and the Caribbean, anemia has been a public health problem that affects mainly women of childbearing age and children under 6 years of age. However, the current prevalence of anemia in this region is unknown. OBJECTIVE: To examine the latest available prevalence data on anemia in Latin America and the Caribbean. METHODS: A systematic review was conducted in 2011 and updated in 2014. Studies determining the prevalence of anemia conducted in apparently healthy populations with national or regional representativeness were included in the review. RESULTS: The lowest prevalence rates of anemia among children under 6 years of age were found in Chile (4.0%), Costa Rica (4.0%), Argentina (7.6%), and Mexico (19.9%). In Nicaragua, Brazil, Ecuador, El Panama, and Honduras, anemia was a moderate public health problem, with prevalence ranging Salvador, Cuba, Colombia, the Dominican Republic, Peru, from 20.1% to 37.3%. Anemia was a severe public health problem in Guatemala, Haiti, and Bolivia. The prevalence of anemia among women of childbearing age was lowest in Chile (5.1%). In Colombia, El Salvador, Costa Rica, Nicaragua, Ecuador, Mexico, Peru, Honduras, and Argentina, anemia was a mild public health problem, with prevalence ranging from 7.6% to 18.7%. In Guatemala, Brazil, the Dominican Republic, and Bolivia, anemia was a moderate public health problem, with prevalence ranging from 21.4% to 38.3%. Panama and Haiti had the highest reported prevalence rates (40.0% and 45.5%, respectively), and anemia was considered a severe public health problem in those countries. CONCLUSIONS: Anemia remains a public health problem in children under 6 years of age and women of childbearing age in most Latin America and Caribbean countries for which data are available.

Interpretation of Serum Retinol Data From Latin America and the Caribbean.

BACKGROUND: In recent decades, the general socioeconomic situation in Latin America and the Caribbean countries has improved, and many vitamin A programs have been implemented in an attempt to reduce vitamin A deficiency in the region. OBJECTIVE: To examine vitamin A status in Latin America and the Caribbean based on serum retinol concentrations and to contrast available data published before and after 1998. METHODS: A systematic review was performed. National surveys or representative studies that reported vitamin A status were selected. RESULTS: Ten national surveys and six representative studies were identified. Data for children under 6 years of age indicate that Guatemala and Nicaragua have practically eradicated vitamin A deficiency (less than 2% prevalence of serum retinol < 20 µg/dL). In Costa Rica, Cuba, El Salvador, and Panama, the prevalence of vitamin A deficiency ranged from 2.8% to 9.4%. In Peru, Honduras, Argentina, Ecuador, and Brazil, vitamin A deficiency is a moderate public health problem (prevalence from 14.0% to 17.4%), while in Colombia, Mexico, and Haiti it is a severe public health problem (prevalence from 24.3% to 32.0%). Disadvantaged groups (indigenous people and those of Afro-Colombian descent) have the highest rates of deficiency. The prevalence of vitamin A deficiency is under 20% in school-children and adult women. When data published before and after 1998 for children under 6 years of age were compared, most Central American countries had a reduction in the prevalence of vitamin A deficiency (p < .05), whereas in South American countries, the prevalence of vitamin A deficiency increased over time (p < .05). CONCLUSIONS: The prevalence of vitamin A deficiency in children under 6 years of age has decreased in many Central American countries, but vitamin A deficiency still remains a public health problem in numerous Latin America and Caribbean countries, especially among disadvantaged and vulnerable groups. Because of issues with the accuracy of the serum retinol biomarker reflecting body stores, these results must be interpreted with caution.

[Seasonal variations in the lipid profile of apparently healthy young adults living in Santiago, Chile]. / Variación estacional del perfil lipídico en adultos aparentemente sanos de Santiago, Chile.

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.

[Prevalence of deficiency and dietary intake of iron, zinc and copper in Chilean childbearing age women]. / Prevalencia de deficiencia y consumo de hierro, zinc y cobre en mujeres chilenas en edad fertil.

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. Partidipants 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.

Low prevalence of iron deficiency anemia between 1981 and 2010 in Chilean women of childbearing age.

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.

Iron status biomarkers and C-reactive protein in children aged 19 to 72 months in Chile.

BACKGROUND: The Chilean Ministry of Health has combated iron deficiency through the delivery of fortified milk by the National Complementary Feeding Program (NCFP). OBJECTIVE: To assess iron status and associations between biomarkers of iron status and serum C-reactive protein (CRP) in 218 beneficiaries of the NCFP aged 19 to 72 months in Santiago and Valparaiso, Chile. METHODS: Blood was collected from a cross-sectional representative sample. Iron status (measured by hemoglobin, zinc protoporphyrin, and serum ferritin levels) and inflammation (according to CRP level) were determined. RESULTS: Serum CRP level was positively associated with serum ferritin and zinc protoporphyrin levels (r = 0.16 and r = 0.15; p = .0168 and p = .0290, respectively). Serum ferritin was higher among children with high CRP (> 10 mg/dL) than among those with low CRP (< or = 10 mg/dL) (p = .003). After adjustment for 10, 6, and 5 mg/L CRP, the prevalence of low serum ferritin changed from 56.4% without adjustment to 60.6%, 61.5%, and 42.7%, respectively, and the prevalence of high zinc protoporphyrin changed from 22.9% to 21.6%, 17.4%, and 17.9%, respectively. There were no differences between regions in biomarkers of iron status. There was no association between consumption of fortified milk and the prevalence of abnormal serum ferritin (< 15 microg/L) after adjustment for sex, age, and breastfeeding (OR, 1.00; 95% CI, 0.99 to 1.01; p = .288). After adjustment for 10 mg/L CRP, 5.5% were classified as having iron-deficiency anemia, 42.7% as having iron-deficiency erythropoiesis, 17.9% as having depleted iron stores, and 35.8% as having normal iron status. CONCLUSIONS. CRP level was positively associated with: serum ferritin and zinc protoporphyrin levels. Chilean children aged 19 to 72 months from Santiago and Valparaiso who were beneficiaries of the NCFP had a low prevalence of iron-deficiency anemia, a high prevalence of iron-deficiency erythropoiesis, and a moderate prevalence of depleted iron stores.

Chilean complementary feeding program reduces anemia and improves iron status in children aged 11 to 18 months.

BACKGROUND: Iron deficiency is the most prevalent nutritional deficiency in the world, primarily affecting infants, young children, and women of childbearing age. OBJECTIVE: To evaluate the impact of the National Complementary Feeding Program (NCFP) on anemia and iron status in Chilean children aged 11 to 18 months. METHODS: Two studies were performed. The first study was performed at one public outpatient health center in Santiago, using data collected in 1999 (n = 128) and 2000 (n = 125), before and after the national introduction of iron-fortified milk. Subsequently, a study of a representative sample (n = 320) from the two most populated areas of the country was performed in 2009. RESULTS: One year after fortification, the prevalence of anemia was 9%; significantly lower (p < .001) than the 27% prevalence observed 1 year before. Ten years after fortification, 14% of children were anemic and 77% of children with anemia (12% of all children) suffered from iron-deficiency anemia. In 2009, 11% of children consuming iron-fortified milk delivered by the NCFP (73%) were anemic, significantly lower (p = .028) than the 21% prevalence of anemia observed in children without consumption. Consumption of iron-fortified milk was positively associated with hemoglobin concentration (r = 0.28, p = .022) and was associated with a lower prevalence of anemia after adjusting for confounding factors (odds ratio, 0.50; 95% CI, 0.26 to 0.96). CONCLUSIONS: In Chile, the NCFP has had an impact on the reduction of anemia and improved the iron status of children aged 11 to 18 months. Increasing the consumption of this iron-fortified milk could enhance the impact of the NCFP.

Less than adequate vitamin D status and intake in Latin America and the Caribbean:a problem of unknown magnitude.

BACKGROUND: The prevalence of vitamin D deficiency in Latin America and the Caribbean is unknown. OBJECTIVE: To examine the prevalence data available on vitamin D deficiency in Latin America and the Caribbean. METHODS: A systematic review was conducted in 2011. Studies using biochemical biomarkers and dietary intake estimation were included. Studies conducted in apparently healthy individuals, independently of age, latitude, skin pigmentation, and season of the year at the time of blood collection, were included. RESULTS: A total of 243 studies were identified. The final number of selected studies was 28, including two National Health Surveys (Mexico and Argentina). There are studies that report the vitamin D status of specific subgroups conducted in Argentina, Brazil, Chile, Colombia, Ecuador, Guatemala, and Mexico. However, the small sample sizes in these studies and thus the low national representativeness of the reported data do not allow for an accurate assessment of vitamin D status at the regional level. In the majority of the countries with available data, we observed that vitamin D insufficiency was classified as a mild, moderate, or severe public health problem. The only country with a nationally representative sample was Mexico, which found 24%, 10%, 8%, and 10% prevalence rates of vitamin D insufficiency (25-hydroxyvitamin D < 50 nmol/L) in preschoolers, schoolchildren, adolescents, and adults, respectively. The prevalence of vitamin D deficiency (25-hydroxyvitamin D < 20 nmol/L) was less than 1% for all groups. CONCLUSIONS: There is some indication that vitamin D insufficiency may be a public health problem in Latin America and the Caribbean, but the exact magnitude is currently unknown.

Acute inhibition of iron bioavailability by zinc: studies in humans.

Iron (Fe) and zinc (Zn) deficiencies constitute two of the most important nutritional and public health problems affecting developing countries. Combined supplementation or fortification with Zn and Fe are strategies that can be used to improve the Zn and Fe status of a population. However, there is concern about potential negative interactions between these two micronutrients due to a competitive binding to DMT1 and Zip14 transporter. Studies performed in humans have shown an inhibitory effect of Zn on Fe absorption when both minerals are given together as a solution in fasting conditions. We found that at low doses of iron (0.5 mg) the threshold for the inhibition of iron bioavailability was at a Zn:Fe wt/wt ratio ≥5.9:1, whereas at higher doses of Fe (10 mg) this inhibition occurred at 1:1 Zn:Fe wt/wt ratio. This differential response could be explained by the variation in the abundance of both cations as they compete for a limited number of shared transporters at the enterocyte. Conflicting results have been obtained when this interaction was studied in different food matrices. A negative interaction was not observed when Fe and Zn were provided in a composite hamburger meal, premature formula, human milk, or cow milk. A decrease on Fe absorption was observed in only 1 of 3 studies when Fe and Zn were supplied in wheat flour. The possibility of a negative interaction should be considered for supplementation or fortification programs with both microminerals.

Low prevalence of anemia in children aged 19 to 72 months in Chile.

BACKGROUND: In 1974/75, the prevalence of anemia in Chilean preschoolers was 18.8%. Since 2000, the Chilean Ministry of Health has combated anemia through the delivery of iron-fortified milk by the National Complementary Feeding Program (NCFP). OBJECTIVE: To determine the prevalence of anemia in children aged 19 to 72 months who are beneficiaries of the NCFP. METHODS: A cross-sectional representative sample of 224 beneficiaries of the NCFP aged 19 to 72 months from the Santiago and Valparaiso regions was recruited. RESULTS: The mean (+/- SD) hemoglobin concentration was 12.3 +/- 1.0 g/dL. Four percent of all children studied were anemic. In simple linear regression analysis, it was observed that hemoglobin concentration was positively correlated with age (r = 0.23, p = .001). There was no association between hemoglobin concentration and duration of breastfeeding (r = -0.12, p = .175). The prevalence of anemia among the 69% of children consuming iron-fortified milk delivered by NCFP was 2.6%, as compared with 7.1% among children not consuming iron-fortified milk (p = 0.227). Consumption of iron-fortified milk did not show a positive significant relationship with hemoglobin concentration (r = 0.063, p = .529). Similarly, multiple logistic regression did not show an association between consumption of fortified milk and anemia, after adjusting for sex, age, and breastfeeding (p = .150; OR = 0.98; 95% CI, 0.95 to 0.10). CONCLUSIONS: In 2009 anemia was not a public health problem in Chilean children aged 19 to 72 months from Santiago and Valparaiso.

[Folate, vitamin B12 and human health]. / Folatos y vitamina B12 en la salud humana.

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. Poor folate 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.

Reduction in thermal stress of marine copepods after physiological acclimation.

We studied the phenotypic response to temperature of the marine copepod Paracartia grani at the organismal and cellular levels. First, the acute (2 days) survival, feeding and reproductive performances at 6-35°C were determined. Survival was very high up to ca. 30°C and then dropped, whereas feeding and fecundity peaked at 23-27°C. An acclimation response developed after longer exposures (7 days), resulting in a decline of the biological rate processes. As a consequence, Q10 coefficients dropped from 2.6 to 1.6, and from 2.7 to 1.7 for ingestion and egg production, respectively. Due to the similarity in feeding and egg production thermal responses, gross-growth efficiencies did not vary with temperature. Respiration rates were less sensitive (lower Q10) and showed an opposite pattern, probably influenced by starvation during the incubations. The acclimation response observed in the organismal rate processes was accompanied by changes in body stoichiometry and in the antioxidant defense and cell-repair mechanisms. Predictions of direct effects of temperature on copepod performance should consider the reduction of Q10 coefficients due to the acclimation response. Copepod population dynamic models often use high Q10 values and may overestimate thermal effects.

Calcium does not inhibit the absorption of 5 milligrams of nonheme or heme iron at doses less than 800 milligrams in nonpregnant women.

Calcium is the only known component in the diet that may affect absorption of both nonheme and heme iron. However, the evidence for a calcium effect on iron absorption mainly comes from studies that did not isolate the effect of calcium from that of other dietary components, because it was detected in single-meal studies. Our objective was to establish potential effects of calcium on absorption of nonheme and heme iron and the dose response for this effect in the absence of a meal. Fifty-four healthy, nonpregnant women were selected to participate in 4 iron absorption studies using iron radioactive tracers. We evaluated the effects of calcium doses between 200 and 1500 mg on absorption of 5 mg nonheme iron (as ferrous sulfate). We also evaluated the effects of calcium doses between 200 and 800 mg on absorption of 5 mg heme iron [as concentrated RBC (CRBC)]. Calcium was administered as calcium chloride in all studies and minerals were ingested on an empty stomach. Calcium doses ≥1000 mg diminished nonheme iron absorption by an average of 49.6%. A calcium dose of 800 mg diminished absorption of 5 mg heme iron by 37.7%. In conclusion, we demonstrated an isolated effect of calcium (as chloride) on absorption of 5 mg of iron provided as nonheme (as sulfate) and heme (as CRBC) iron. This effect was observed at doses higher than previously reported from single-meal studies, starting at ~800 mg of calcium.

[Prevalence of zinc and copper deficiencies in older subjects living in Metropolitan Santiago]. / Prevalencia de las deficiencias de zinc y cobre en adultos mayores de la Región Metropolitana de Santiago.

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 samples from 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 of 444 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.

Exploratory Study: Excessive Iron Supplementation Reduces Zinc Content in Pork without Affecting Iron and Copper.

The aim of this work was to determine in an exploratory manner the effect of excessive iron supplementation on iron, zinc, and copper contents in pork and pork offal. Pigs averaging 50 days in age and 15 ± 1.3 kg body weight were allocated to a control group (500 ppm dietary Fe) and a supplemental group (3000 ppm dietary Fe). After an iron supplementation period of 60 days, blood samples were analyzed to determine iron biomarkers, serum copper, and zinc contents. Animals were slaughtered to assess total iron, non-heme iron, heme iron, zinc, and copper contents in samples of nine meat cuts and some offal. Iron supplementation improved the iron status in pigs with increased hemoglobin and hematocrit, but did not affect serum levels of iron, zinc, and copper. Iron supplementation did not affect the heme and non-heme iron contents of the different meat cuts. Zinc contents decreased by 32-55% in meat cuts, where iron content increased in the liver, spleen, kidneys, and pancreas. No differences of zinc and copper were observed in offal samples. High concentrations of iron supplementation reduce zinc content in pork.

Zinc absorption and zinc status are reduced after either sleeve gastrectomy or Roux-en-Y gastric bypass in premenopausal women with severe obesity studied prospectively over 24 postoperative months.

BACKGROUND: Roux-en-Y gastric bypass (RYGBP) is known to reduce zinc absorption; the effects of vertical sleeve gastrectomy (SG) and its long-term implications on zinc absorption have not yet been studied. OBJECTIVE: The aim was to evaluate the effects of SG and RYGBP on zinc absorption and zinc status in premenopausal women with severe obesity up to 24 mo after surgery. METHODS: Twenty-six premenopausal women undergoing SG [BMI (in kg/m2): 37.3 ± 3.2] and 32 undergoing RYGBP (BMI: 42.0 ± 4.2) were studied. A series of anthropometric, dietary, and zinc status parameters (plasma and hair zinc), and the size of the exchangeable zinc pool (EZP), as well as percentage zinc absorption from a standardized dose using a stable isotope methodology were evaluated in the patients before the surgical procedure and at 12 and 24 mo after SG or RYGBP. SG patients received 15 mg and RYGBP received 25 mg of supplemental Zn/d. RESULTS: In premenopausal women, zinc absorption was decreased by 71.9% and 52.0% in SG and RYGBP, respectively, 24 mo postsurgery, compared with initial values. According to 2-factor repeated-measures ANOVA, time effect was significant (P = <0.0001), but not time × group interaction (P = 0.470). Plasma zinc below the cutoff point of 70 µg/dL increased from 0 to 15.4% and 38.1% in SG and RYGBP, respectively. Mean EZP was significantly reduced 24 mo after surgery, although no time × group interactions were observed. Hair zinc did not change across time or between groups. CONCLUSIONS: Both SG and RYGBP have profound effects on zinc absorption capacity, which are not compensated for after 24 mo. Although zinc absorption reduction was similar in both types of surgeries, plasma zinc was more affected in RYGBP than SG, despite greater zinc supplementation in RYGBP.This trial was registered at http://www.isrctn.com as ISRCTN31937503.

Non-lethal effects of the predator Meganyctiphanes norvegica and influence of seasonal photoperiod and food availability on the diel feeding behaviour of the copepod Centropages typicus.

Predators can induce changes in the diel activity patterns of marine copepods. Besides vertical migration, diel feeding rhythms have been suggested as an antipredator phenotypic response. We conducted experiments to assess the non-lethal direct effects of the predator Meganyctiphanes norvegica (northern krill) on the diel feeding patterns of the calanoid copepod Centropages typicus. We also analysed the influence of seasonal photoperiod and prey availability on the intensity of copepod feeding rhythms. We did not detect any large effect of krill presence on the diel feeding behaviour of copepods, either in day-night differences or total daily ingestions. Seasonal photoperiod and prey availability, however, significantly affected the magnitude of copepod feeding cycles, with larger diel differences in shorter days and at lower prey concentrations. Therefore, the role of non-lethal direct effects of predators on the diel feeding activity of marine copepods remain debatable and might not be as relevant as in freshwater zooplankton.