Zinc and its role in vitamin D function

Multifaceted determinants of micronutrient status in early childhood in Iran : National food and nutrition surveillance

PURPOSE

This study examined the status and determinants of key micronutrients among 24-60 month children in underprivileged provinces of Iran, highlighting ongoing challenges despite intervention efforts.

METHODS

This study analyzed data from the National Food and Nutrition Surveillance program. A multistage cluster sampling method was used, recruiting 280 children per province from Khuzestan, Kerman, Ilam, Bushehr, Hormozgan, Kohgiluyeh va Boyerahmad, Sistan va Baluchestan and South Khorasan. Demographic, dietary, and anthropometric data were collected, and micronutrient status was assessed through hemoglobin, serum ferritin, zinc, retinol and 25-hydroxycalciferol assays.

RESULTS

This study included 2,247 children (42.2 ± 0.3 months). About 40% of children had low dietary diversity, and 48.4% were from low socioeconomic status (SES) families. Anemia was found in 24% of the children. Vitamin D and A deficiency affected 74%, and 22.3% of children, respectively. Notably, 39.1% had multiple micronutrient deficiencies. Father's occupation (odds ratio [OR] (95% confidence interval [CI]; freelance vs. employed: 1.86 (1.13, 3.06), worker vs. employed: 2.3 (1.43, 3.69)) and SES (middle vs. high: 2.15 (1.09, 4.2)) were significant predictors of anemia. Urban living and higher paternal education were protective against low ferritin. Children in lower SES categories and those with poor vitamin D status were more likely to have iron (1.53 (1.12, 2.09), p = 0.007) and zinc deficiencies (2.19 (1.46, 3.29) p < 0.001). Vitamin A and D statuses were mainly influenced by SES, food security, and supplement intake, respectively.

CONCLUSION

Our findings revealed high prevalence of micronutrient deficiencies among 24-60 month children residing in eight underprivileged provinces of Iran. Parental education, household SES and food security were the main determinants of micronutrient deficiencies among the studied children. Improvement of the households' food access through betterment of economic condition seems inevitable which in turn necessitates an inter-sectorial collaboration.

Tracing Zinc's Role in Preterm Infants' Health: A Narrative Review

Zinc (Zn) is a trace element involved in numerous physiological processes, including enzyme function, gene transcription, and cell signaling. Its importance is especially pronounced in preterm infants, who are at high risk of Zn deficiency due to disrupted transplacental transfer, high nutrient demands, and medical complications. The inherent risk of Zn deficiency in this population is further increased by poor Zn dietary intake. Human milk from preterm mothers contains low concentrations of Zn, although it is highly bioavailable. Additionally, the Zn content steadily declines from colostrum (first few days postpartum) to mature milk (>10-14 d postpartum). Formula milk contains higher Zn concentrations to compensate for nutrient losses during production and storage, and lower bioavailability compared with human milk, which is further decreased in case of high phytate content, such as in soy milk-based formulas. Zn supplements may prove useful in meeting the preterm infant's needs, although caution is warranted regarding potential interactions with other nutrients within multinutrient supplements. Early detection of Zn deficiency is challenging due to the lack of reliable Zn status biomarkers, necessitating a high index of suspicion. Clinical signs of Zn deficiency can range from mild, nonspecific symptoms to severe, multisystem involvement. Chronic deficiency may lead to failure to thrive. Zn supplementation can support growth and mitigate comorbidities in preterm infants, although variability across studies complicates efforts to establish optimal dosing, and define safety and long-term effects. Although rare, Zn toxicity in preterm infants should not be overlooked, especially in infants on long-term parenteral nutrition. This narrative review aimed to consolidate existing knowledge and identify research gaps, highlighting the critical role of Zn in supporting preterm infants' health. Further research is needed to establish evidence-based practices to improve health outcomes in this vulnerable population.

Effect of Oral Zinc Supplementation on Phase Angle and Bioelectrical Impedance Vector Analysis in Duchenne Muscular Dystrophy: A Non-Randomized Clinical Trial

Zinc plays a crucial role in cell structure and functionality. Neurodegenerative Duchenne muscular dystrophy (DMD) alters muscle membrane structure, leading to a loss of muscle mass and strength. The objective of this study was to evaluate the changes in phase angle (PA) and bioelectrical impedance vector analysis (BIVA) results in patients with DMD after oral zinc supplementation. This clinical trial included 33 boys aged 5.6 to 24.5 years diagnosed with DMD. They were divided into three groups according to age (G1, G2, and G3) and supplemented with oral zinc. The mean serum zinc concentration was 74 μg/dL, and 29% of patients had concentrations below the reference value. The baseline values (mean (standard deviation)) of the bioelectrical impedance parameters PA, resistance (R), and reactance (Xc) were 2.59° (0.84°), 924.36 (212.31) Ω, and 39.64 (8.41) Ω, respectively. An increase in R and a decrease in PA and lean mass proportional to age were observed, along with a negative correlation (r = -0.614; p < 0.001) between age and PA. The average cell mass in G1 was greater than that in G3 (p = 0.012). There were no significant differences in serum zinc levels or bioelectrical impedance parameters before and after zinc supplementation. We conclude that this population is at risk of zinc deficiency and the proposed dosage of zinc supplementation was not sufficient to alter serum zinc levels, PA and BIVA results.

Zinc and Diabetes: A Connection between Micronutrient and Metabolism

Diabetes mellitus is a global health problem and a major contributor to mortality and morbidity. The management of this condition typically involves using oral antidiabetic medication, insulin, and appropriate dietary modifications, with a focus on macronutrient intake. However, several human studies have indicated that a deficiency in micronutrients, such as zinc, can be associated with insulin resistance as well as greater glucose intolerance. Zinc serves as a chemical messenger, acts as a cofactor to increase enzyme activity, and is involved in insulin formation, release, and storage. These diverse functions make zinc an important trace element for the regulation of blood glucose levels. Adequate zinc levels have also been shown to reduce the risk of developing diabetic complications. This review article explains the role of zinc in glucose metabolism and the effects of its inadequacy on the development, progression, and complications of diabetes mellitus. Furthermore, it describes the impact of zinc supplementation on preventing diabetes mellitus. The available information suggests that zinc has beneficial effects on the management of diabetic patients. Although additional large-scale randomized clinical trials are needed to establish zinc's clinical utility further, efforts should be made to increase awareness of its potential benefits on human health and disease.

Calcium, Phosphate, and Vitamin D in Children and Adolescents with Chronic Diseases: A Cross-Sectional Study

Chronic diseases may affect the nutritional status of children and adolescents. Calcium (Ca), phosphorus (P), and vitamin D (Vit-D) are crucial nutrients for their growth and development. Proper diagnosis and treatment are critical components of personalized and precision medicine. Hence, we conducted a cross-sectional and comparative study to evaluate Ca, P, and Vit-D levels in their non-skeletal functions and their association with health and nutritional biomarkers in children and adolescents with diverse chronic conditions. We performed anthropometric, body composition, clinical evaluation, biochemical analysis, and dietary survey methods. A total of 78 patients (1-19 years, 43 females, 42 children) took part in this study. Overall, 24, 30, and 24 participants were obese, undernourished, and eutrophic, respectively. Results found that 74% and 35% of individuals had deficient Vit-D and Ca intake, respectively. Most cases were normocalcemic. Results also found that 47% of the subjects had Vit-D deficiency (VDD), 37% were insufficient, and 37% had hypophosphatemia. Of the 46% and 31% of patients with VDD and insufficient levels, 19% and 11% were hypophosphatemic, respectively. Calcium, P, and Vit-D levels were associated with anthropometric parameters, body mass index, body composition, physical activity, diet, growth hormones, and the immune, liver, and kidney systems. These results show the coincident risk of altered Ca, P, and Vit-D metabolism in children and adolescents with chronic diseases.

Effect of Zinc Supplementation on Altered Calcium Homeostasis, Parathyroid Gland, Bone, and Skeletal Muscle Histology Induced by Subchronic Oral Exposure to Glyphosate-Based Herbicide (GOBARA®) in Wistar Rats

Objectives

The study was carried out to assess the effect of zinc supplementation on changes in calcium homeostasis, and parathyroid gland, bone, and skeletal muscle histology in rats exposed to subchronic oral glyphosate-based herbicide (GBH, GOBARA®) toxicity.

Methods

Sixty male Wistar rats in 6 equal groups (DW, Z, G1, G2, ZG1, ZG2) were used: DW and Z were given 2 mL/kg distilled water and 50 mg/kg of zinc chloride (2%), respectively; G1 and G2 received 187.5 mg/kg and 375 mg/kg of glyphosate (in GBH), respectively; ZG1 and ZG2 were pretreated with 50 mg/kg of zinc chloride before receiving glyphosate, 1 hour later, at 187.5 and 375 mg/kg, respectively. Treatments were by gavage once daily for 16 weeks. Serum calcium, vitamin D, and parathormone were estimated. Histopathological examination of parathyroid gland, femoral bone and biceps femoris muscle was done.

Results

GBH exposure caused significant (P = .0038) decrease in serum calcium concentration in G1, significant (P = .0337) decrease in serum vitamin D concentration in G1, significant increases in parathormone in G1 (P = .0168) and G2 (P = .0079) compared to DW. Significant (P > .05) changes did not occur in the other parameters of G2 compared to DW. Dose-dependent effect in GBH exposure was not observed after comparing G1 and G2. Necrotic changes occurred in parathyroid gland cells, osteocytes, and muscle cells in G1 and G2. In ZG1 and ZG2, significant (P > .05) variations in the parameters were not observed and tissue lesions were absent.

Conclusion

Subchronic GBH exposure impaired calcium homeostasis observed as hypocalcemia, hypovitaminemia D, and secondary hyperparathyroidism and caused tissue damage in parathyroid gland, bone, and muscle of rats and these were mitigated by zinc chloride pretreatment.

Association between female circulating heavy metal concentration and abortion: a systematic review and meta-analysis

Objective

This study aimed to evaluate the association between blood heavy metal (zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd)) concentrations and spontaneous abortion (SA) and recurrent pregnancy loss (RPL) and explore the possible endocrine dysfunction associated with it.

Methods

A literature search was performed in the PubMed, Embase, Cochrane Library, and Web of Science databases up to April 2023. The overall effects were expressed as the standard mean difference (SMD). Subgroup analysis was performed according to the type of abortion (SA or RPL). Stata 16.0 was utilized for data analysis.

Results

Based on the integrated findings, abortion women showed significantly lower Zn (SMD = -1.05, 95% CI: -1.74 to -0.36, p = 0.003) and Cu concentrations (SMD = -1.42, 95% CI: -1.97 to -0.87, p <0.001) and higher Pb (SMD = 1.47, 95% CI: 0.89-2.05, p <0.001) and Cd concentrations (SMD = 1.15, 95% CI: 0.45-1.85, p = 0.001) than normal pregnant women. Subgroup analysis showed that Zn and Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with RPL, whereas Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with SA.

Conclusion

Zn and Cu deficiencies and Pb and Cd exposure were associated with abortion. Endocrine dysfunction, such as insulin resistance, vitamin D insufficiency, and abnormal thyroid and sex hormone concentrations, is thought to be involved in heavy metal-related abortion.

Zinc supplement reverses short-term memory deficit in sodium benzoate-induced neurotoxicity in male Wistar rats by enhancing anti-oxidative capacity via Nrf 2 up-regulation

Sodium benzoate (SB) is a commonly-used food preservative, with a controversial report to its neurological benefit and toxicity. Zinc (Zn) is a trace element that plays a crucial role in memory, inflammation and oxidative stress. This study was to investigate the effect of SB on rat cognition and memory and the possible modulatory effect of Zn supplement. Twenty four male Wistar rats were divided into four groups of six animals each. Animals in groups 1-4 were treated with normal saline 1 ml/kg, SB 200 mg/kg, zinc sulphate 10 ml/kg and SB 200 mg/kg + zinc sulphate 10 ml/kg/day daily respectively for three weeks. After treatment, the animals were subjected to different behavioural tests, and then sacrificed. Their blood samples were collected for catalase(CAT), superoxide dismutase(SOD) and interleukin-1B(IL-1B) assay. Brain samples were also collected for nuclear factor-erythroid-related factor 2(Nrf2), and acetylcholinesterase (AchE) mRNA gene expression. The serum levels of CAT and SOD were (p < 0.0001; p < 0.0001) reduced in the SB only-treated group compared to the other groups. Nrf2 gene expression was totally shut down in the SB only-treated group but, up-regulated in the Zn-treated groups (p < 0.0001). The serum level of IL-1B was higher in the SB only-treated group compared to the other groups. SB-treated group spent longer time in the close arm (p = <0.0001), shorter time in the open arm (p = <0.0001) and had higher anxiety index (p = 0.0045) than the Zn-treated groups. Conclusively, Zinc improves memory deficit, has anxiolytic, anti-oxidant and anti-inflammatory properties.

Zinc Chloride Enhances the Antioxidant Status, Improving the Functional and Structural Organic Disturbances in Streptozotocin-Induced Diabetes in Rats

Background and Objectives: Diabetes mellitus (DM) is a complex disease affecting the whole metabolic balance of the body and resulting in multiple organ complications: cardiovascular, neuronal, renal, etc. Our study focuses on investigating the effect of zinc chloride (Zn) on certain blood parameters suggestive for assessing the metabolic disturbances, the liver and kidney function, the oxidative stress and the immune defense capacity in experimental-induced DM with streptozotocin (STZ) and cholesterol in rats. Materials and Methods: The animals were assigned to three groups, as follows: Group 1 (Control): buffer citrate solution 0.1 mL/100 g body; Group 2 (STZ): 20 mg/kg body STZ and fat diet (10 g cholesterol/100 g diet); Group 3 (STZ+Zn): 20 mg/kg body STZ + 5 mg/kg body Zn chloride and the same fat diet. DM was induced by administering STZ in a single take daily, for three consecutive days, Zn and citrate buffer were administered orally for a month. The protocol was approved by the Ethics Committee of the University 'Grigore T Popa' Iasi, in agreement with the International Regulations about the handling of laboratory animals. Results: The use of STZ in rats fed with cholesterol was correlated with important weight gain, hyperglycemia, the intensification of the transaminases activity and the increase in serum alkaline phosphatase, cholesterol, triglyceride, urea, creatinine and in malondialdehyde. Conclusions: The treatment with Zn resulted in weight loss and a decrease in blood sugar in diabetic rats. Supplementation with Zn notably reduced oxidative stress, preserved the pancreatic architecture and restored the liver and kidney function and structure in STZ-induced DM in rats.

Phosphate Dysregulation and Metabolic Syndrome

Phosphorus is one of the most abundant minerals in the human body. It is essential for almost all biochemical activities through ATP formation, intracellular signal transduction, cell membrane formation, bone mineralization, DNA and RNA synthesis, and inflammation modulation through various inflammatory cytokines. Phosphorus levels must be optimally regulated, as any deviations may lead to substantial derangements in glucose homeostasis. Clinical studies have reported that hyperphosphatemia can increase an individual's risk of developing metabolic syndrome. High phosphate burden has been shown to impair glucose metabolism by impairing pancreatic insulin secretion and increasing the risk of cardiometabolic disorders. Phosphate toxicity deserves more attention as metabolic syndrome is being seen more frequently worldwide and should be investigated further to determine the underlying mechanism of how phosphate burden may increase the cardiometabolic risk in the general population.

Interactions between FGF23 and vitamin D

Fibroblast growth factor-23 (FGF23) controls the homeostasis of both phosphate and vitamin D. Bone-derived FGF23 can suppress the transcription of 1α-hydroxylase (1α(OH)ase) to reduce renal activation of vitamin D (1,25(OH)2D3). FGF23 can also activate the transcription of 24-hydroxylase to enhance the renal degradation process of vitamin D. There is a counter-regulation for FGF23 and vitamin D; 1,25(OH)2D3 induces the skeletal synthesis and the release of FGF23, while FGF23 can suppress the production of 1,25(OH)2D3 by inhibiting 1α(OH)ase synthesis. Genetically ablating FGF23 activities in mice resulted in higher levels of renal 1α(OH)ase, which is also reflected in an increased level of serum 1,25(OH)2D3, while genetically ablating 1α(OH)ase activities in mice reduced the serum levels of FGF23. Similar feedback control of FGF23 and vitamin D is also detected in various human diseases. Further studies are required to understand the subcellular molecular regulation of FGF23 and vitamin D in health and disease.

The Clinical Significance of Vitamin D and Zinc Levels with Respect to Immune Response in COVID-19 Positive Children

AIM

In this study, we aimed to evaluate serum vitamin D and zinc levels in children diagnosed with coronavirus disease 2019 (COVID-19).

MATERIALS AND METHODS

In this study, 88 children with COVID-19 disease and 88 healthy children aged 1-18 years were enrolled between 01 July 2021 and 30 October 2021 in the Pediatrics Clinic of Tekirdağ Çorlu State Hospital. Serum vitamin D and zinc levels have been measured and NCSS (Number Cruncher Statistical System) program has been utilized for statistical analysis.

RESULTS

We included 88 COVID-19 positive pediatric patients [50% (n = 44) female] and 88 healthy children [48.86% (n = 43) female] in this study. The mean serum vitamin D levels of COVID-19 positive patients were statistically significantly lower than the control group (p = 0.0001). The zinc mean values of the study group were found to be statistically significantly lower than the control group (p = 0.0001). There was a statistically significant correlation between serum vitamin D and zinc values in all patient groups (r = 0.245, p = 0.001).

CONCLUSION

As a result, zinc and vitamin D levels were observed lower in COVID-19 patients than in healthy individuals. Since there is no defined treatment protocol for COVID-19 infection on children yet, zinc and vitamin D supplementation can be used as a supportive treatment in COVID-19 infection.