Dietary Intake and Urinary Excretion of Manganese in Korean Healthy Adults

Role of Nutrients in Pediatric Non-Dialysis Chronic Kidney Disease: From Pathogenesis to Correct Supplementation

Nutrition management is fundamental for children with chronic kidney disease (CKD). Fluid balance and low-protein and low-sodium diets are the more stressed fields from a nutritional point of view. At the same time, the role of micronutrients is often underestimated. Starting from the causes that could lead to potential micronutrient deficiencies in these patients, this review considers all micronutrients that could be administered in CKD to improve the prognosis of this disease.

Sex-Specific Associations of Urinary Metals with Renal Function: a Cross-sectional Study in China

BACKGROUND

Extensive studies have revealed the link between heavy metals and CKD. Compared to single meta-elements, mixture of metals reflect real-life metals exposure scenarios and are of interest. However, the mechanism of action of metal mixture on renal function is unclear.

METHODS

This study aimed to explore the potential relationship between urinary arsenic (As), cadmium (Cd), lead (Pb), manganese (Mn), and chromium (Cr) contents with estimated glomerular filtration rate (eGFR) levels in 2775 participants. The levels of metals in urine were determined by inductively coupled plasma-mass spectrometry. We used linear regression models and the Bayesian kernel machine regression (BKMR) to evaluate the association between metals and eGFR levels.

RESULTS

In linear regression analysis, urinary As (β = 2.723, 95%CI: 0.29, 5.157) and Pb (β = 3.081, 95%CI: 1.725, 4.438) were positively associated with eGFR in the total population. In the BKMR model, a mixture of the five metals had a positive joint effect on eGFR levels, while Pb (PIP = 0.996) contributed the most to eGFR levels. Pb was positively associated with eGFR levels in the total participants and women. As was positively correlated with eGFR levels in women. Pb and eGFR levels were positively correlated when the other metals were set at 25th, 50th, and 75th percentiles.

CONCLUSIONS

To the best of our knowledge, all five metals mixed exposure was positively associated with eGFR. Pb showed more important effects than the other four metals in the mixture, especially in women.

The Potential of Condiments, Seasonings, and Bouillon Cubes to Deliver Essential Micronutrients in Asia: Scenario Analyses of Iodine and Iron Fortification

Micronutrient deficiencies are still highly prevalent in Asia. Fortification of cooking aids, such as condiments (fish and soy sauces), seasonings, and bouillon cubes, may be an additional strategy to improve micronutrient intake. The current study evaluated the potential impact of iodine and iron fortification of cooking aids on micronutrient intake in Asian countries. A systematic literature search was performed to collect consumption data from different countries in Asia. Data from 18 studies in nine Asian countries were included. Scenario analyses were performed using different fortification levels based on regulations and literature. Mean intake of cooking aids ranged from 3.2-15.9 g/day for condiments and 0.4-11.7 g/day for seasonings and bouillon cubes. When replacing salt with iodized salt (30 µg of iodine/g of salt), iodine intake would increase by 13-119 µg/day for soy and fish sauces (9-80% of the Nutrient Reference Value (NRV)), and 5-83 µg/day for bouillon cubes and seasonings (4-56% of the NRV). Fortification with iron 0.5 mg/g food product for condiments or 1 mg/g food product for bouillon cubes and seasonings improved iron intake for soy and fish sauces by 1.6-8.0 mg/day (11-57% of the NRV), and for bouillon cubes and seasonings by 0.4-5.6 mg/day (3-40% of the NRV). These results indicate that, depending on the consumption pattern, fortification of cooking aids can be a suitable strategy to increase intake of micronutrients.

Biomarkers of environmental manganese exposure

We conducted a critical review on biomarkers of environmental manganese (Mn) exposure to answer the following questions: 1) are there reliable biomarkers of internal Mn exposure (Mn in biological matrices) associated with external metrics of Mn exposure (Mn in environmental media)? and 2) are there accurate reference values (RVs) for Mn in biological matrices? Three bibliographic databases were searched for relevant references and identified references were screened by two independent reviewers. Of the 6342 unique references identified, 86 articles were retained for data abstraction. Our analysis of currently available evidence suggests that Mn levels in blood and urine are not useful biomarkers of Mn exposure in non-occupational settings. The strength of the association between Mn in environmental media and saliva was variable. Findings regarding the utility of hair Mn as a biomarker of environmental Mn exposure are inconsistent. Measurements of Mn in teeth are technically challenging and findings on Mn in tooth components are scarce. In non-occupationally exposed individuals, bone Mn measurements using in vivo neutron activation analysis (IVNAA) are associated with large uncertainties. Findings suggest that Mn in nails may reflect Mn in environmental media and discriminate between groups of individuals exposed to different environmental Mn levels, although more research is needed. Currently, there is no strong evidence for any biological matrix as a valid biomarker of Mn exposure in non-occupational settings. Because of methodological limitations in studies aimed at derivation of RVs for Mn in biological materials, accurate RVs are scarce.

Association of Manganese Biomarker Concentrations with Blood Pressure and Kidney Parameters among Healthy Adolescents: NHANES 2013-2018

Deficiency or excess exposure to manganese (Mn), an essential mineral, may have potentially adverse health effects. The kidneys are a major organ of Mn site-specific toxicity because of their unique role in filtration, metabolism, and excretion of xenobiotics. We hypothesized that Mn concentrations were associated with poorer blood pressure (BP) and kidney parameters such as estimated glomerular filtration rate (eGFR), blood urea nitrogen (BUN), and albumin creatinine ratio (ACR). We conducted a cross-sectional analysis of 1931 healthy U.S. adolescents aged 12-19 years participating in National Health and Nutrition Examination Survey cycles 2013-2014, 2015-2016, and 2017-2018. Blood and urine Mn concentrations were measured using inductively coupled plasma mass spectrometry. Systolic and diastolic BP were calculated as the average of available readings. eGFR was calculated from serum creatinine using the Bedside Schwartz equation. We performed multiple linear regression, adjusting for age, sex, body mass index, race/ethnicity, and poverty income ratio. We observed null relationships between blood Mn concentrations with eGFR, ACR, BUN, and BP. In a subset of 691 participants, we observed that a 10-fold increase in urine Mn was associated with a 16.4 mL/min higher eGFR (95% Confidence Interval: 11.1, 21.7). These exploratory findings should be interpreted cautiously and warrant investigation in longitudinal studies.

Identifying the Food Sources of Selected Minerals for the Adult European Population among Rice and Rice Products

The problem of dietary deficiency of several essential elements among different stages of life is still observed. The consumption of whole grains (among others unprocessed rice) is recommended as a part of a healthy diet. This research aimed to determine the content of selected macro- and microelements in rice and rice products to verify whether the tested products could be regarded as a source of selected minerals in the diet of the adult European population.

METHODS

A total of 99 samples from 12 groups of rice products (basmati, black, brown, parboiled, red, wild, white rice and expanded rice, rice flakes, flour, pasta, and waffles) were obtained. The atomic absorption spectrometry method (AAS) was used to determine the content of Ca, Cu, Fe, Mg, Mn, Se and Zn in the study material.

RESULTS

The average measured contents of Ca, Cu, Fe, Mg, Mn, Se and Zn were as follows: 226.3 ± 160.6 mg/kg, 3.6 ± 2.8 mg/kg, 9.4 ± 7.0 mg/kg, 618.0 ± 498.4 mg/kg, 16.7 ± 10.0 mg/kg, 242.9 ± 140.4 µg/kg and 19.5 ± 15.0 mg/kg, respectively. Statistical analyses confirmed the differences in the levels of the studied elements between the subgroups of processed and unprocessed products. Considering the tolerable upper intake level of studied elements, the tested products could be regarded as safe to consume.

CONCLUSION

All tested products can be recommended as a source of Cu, Mn, and Se, while a majority of studied products can be considered a source of Mg and Zn in the diet of the adult European population.

Implementation of Dietary Reference Intake Standards in Prison Menus in Poland

Adequate nutrition in prisons should constantly be monitored due to the limited possibilities of external control as well as the low catering budget for prison meals and poorly defined requirements in this regard. The aim of the study was to assess the nutritional value of meals served in Polish prisons. Using a computer program, 14-day regular and bland diets from 30 prisons were analyzed. The energy value of the meals and the percentage of energy provided by protein, fat, and carbohydrate contained therein were found to meet the recommendations of the Polish National Food and Nutrition Institute. The amount of minerals supplied with the diet did not cover the recommended dietary allowance (RDA) in the case of calcium and magnesium. Particularly disturbing was the excessive supply of sodium in the regular and bland diets, which covered 537% and 311% of the dietary reference intake (DRI), respectively, as well as phosphorus (194 and 192% of RDA). The largest vitamin deficiencies were recorded for vitamins D and C and folate. An especially excessive supply was observed for vitamins A and B₁₂. The type of diet significantly differentiated the average content of over half of the analyzed components, whereas the season of the year turned out to be statistically insignificant. The results of the present investigations indicate a need for development of more accurate legal provisions to regulate the nutrition in Polish prisons in terms of not only the energy value and macronutrient supply but also the intake of minerals and vitamins.