Magnesium, zinc and copper estimation in children with attention deficit hyperactivity disorder (ADHD)

Investigating the Association Between Heavy Metals and Attention Deficit Hyperactivity Disorder in Children: An Exploratory Study

Exposure to heavy metals has been associated with affecting children's neurodevelopment, particularly increasing the risk of developing attention-deficit hyperactivity disorder (ADHD). The current exploratory study aims to investigate potential associations between presence of 15 different heavy metals in urine and ADHD. A total of 190 urine samples of participants from clinical and non-clinical population (non-ADHD = 66; ADHD = 124) aged between 6 and 15 years from Barcelona and Tarragona (Spain) were analysed. Logistic regressions adjusted by sex, age, SES, BMI and diet quality were performed. Highest quartiles (3rd and 4th) of Pb (lead) (aOR 5.33; CI [1.89, 14.98]), Cd (cadmium) (aOR 3.69, CI [1.38, 9.83]), Cu (copper) (aOR 16.46, CI [4.66, 58.14]) and Sb (antimony) (aOR 3.04, CI [1.12, 8.23]) were significantly associated with increased odds of ADHD DSM-5 diagnosis. Additionally, Cu and Cd were associated with higher scores of inattention symptoms. Whereas, Cu and Sb were associated with hyperactivity-impulsivity severity. This exploratory study provides preliminary valuable evidence, suggesting potential associations between environmental factors, such as metal exposure, with ADHD in school-aged children. These findings highlight the importance of further research to support these associations and, if confirmed, explore strategies to mitigate the potential impacts of these toxicants on children's health.

Gut dysbiosis as a driver of neuroinflammation in attention-deficit/hyperactivity disorder: A review of current evidence

There is mounting evidence for the involvement of the immune system, neuroinflammation and disturbed gut microbiota, or dysbiosis, in attention-deficit/hyperactivity disorder (ADHD). Gut dysbiosis is strongly implicated in many physical, autoimmune, neurological, and neuropsychiatric conditions, however knowledge of its particular pathogenic role in ADHD is sparse. As such, this narrative review examines and synthesizes the available evidence related to inflammation, dysbiosis, and neural processes in ADHD. Minimal differences in microbiota diversity measures between cases and controls were found, however many relative abundance differences were observed at all classification levels (phylum to strain). Compositional differences of taxa important to key gut-brain axis pathways, in particular Bacteroides species and Faecalibacterium, may contribute to inflammation, brain functioning differences, and symptoms, in ADHD. We have identified one possible model of ADHD etiopathogenesis involving systemic inflammation, an impaired blood-brain barrier, and neural disturbances as downstream consequences of gut dysbiosis. Nevertheless, studies conducted to date have varied degrees of methodological rigour and involve diverse participant characteristics and analytical techniques, highlighting a need for additional research.

Increased risk of attention-deficit/hyperactivity disorder in adolescents with high salivary levels of copper, manganese, and zinc

Exposure to toxic heavy metals has been associated with the development of attention-deficit/hyperactivity disorder (ADHD). However, fewer studies have examined the associations between abnormal levels of essential trace metals and ADHD, and none have done so using saliva. We investigated whether salivary metals were associated with ADHD in adolescents aged 12 from the Family Life Project (FLP) using a nested case-control study design that included 110 adolescents who met diagnostic criteria for inattentive (ADHD-I), hyperactive-impulsive (ADHD-H), or combined type ADHD (ADHD-C) (cases) and 173 children who did not (controls). We used inductively coupled plasma optical emission spectrophotometry to measure chromium, copper, manganese, and zinc in saliva samples. We employed logistic regression models to examine associations between quartile levels of individual metals and ADHD outcomes by subtype. Salivary copper levels were significantly associated with increased odds of any ADHD diagnosis (OR = 3.31, 95% CI: 1.08-10.12; p = 0.04) and with increased odds of ADHD-C diagnosis (OR = 8.44, 95% CI: 1.58-45.12; p = 0.01). Salivary zinc levels were significantly associated with increased odds of ADHD-C diagnosis (OR = 4.06, 95% CI: 1.21-13.69; p = 0.02). Salivary manganese levels were also significantly associated with increased odds of ADHD-C diagnosis (OR = 5.43, 95% CI: 1.08-27.27, p = 0.04). This is the first study using saliva to assess metal exposure and provide a potential link between salivary levels of copper, manganese, and zinc and ADHD diagnoses in adolescents. Public health interventions focused on metal exposures might reduce ADHD incidence in low-income, minority communities.

Copper/Zinc Ratio in Childhood and Adolescence: A Review

Both copper (Cu) and zinc (Zn) are crucial micronutrients for human growth and development. This literature review covered the last five years of available evidence on the Cu/Zn ratio in children and adolescents. We searched PubMed, Web of Science, Google Scholar, Cochrane Library, and Science Direct for publications between 2017 and 2022, especially in English, although publications in other languages with abstracts in English were included. The main terms used were "copper", "zinc", "copper-zinc", and "zinc-copper" ratios. Cu and Zn determinations made in blood, plasma, or serum were included. This review comprises several cross-sectional and case-control studies with substantial results. The bibliographic search generated a compilation of 19 articles, in which 63.2% of the studies mostly reported a significantly higher Cu/Zn ratio, and 57.9% of them informed significantly lower levels of Zn. We conclude that children and adolescents with acute and chronic conditions are at greater risk of developing elevated Cu/Zn ratios, related to altered nutritional, infectious, and inflammatory status.

The Effects of Vitamin Therapy on ASD and ADHD: A Narrative Review

The effects of a sufficient amount of vitamins and nutrients on the proper function of the nervous system have always been regarded by scientists. In recent years, many studies have been done on controlling or improving the symptoms of neurological and behavioral disorders created by changes in the level of vitamins and other nutrition, such as omega-3 and iron supplements. Autism spectrum disorder (ASD) is a neurodevelopmental disorder that disrupts individual communication, especially in social interactions. Its symptoms include anxiety, violence, depression, self-injury, trouble with social contact and pervasive, stereotyped, and repetitive behavior. ASD is most noticeable in early childhood. Attention Deficit Hyperactivity Disorder (ADHD) is a lasting pattern of inattention with or without hyperactivity that causes functional disruption in daily life. ADHD symptoms included; impulsivity, hyperactivity, inattention, restlessness, talkativeness, excessive fidgeting in situations such as sitting, meetings, lectures, or at the movies, boredom, inability to make decisions, and procrastination. The exact etiology of ADHD has not yet been found, but several observations have assumed the reduced function of the brain leads to deficits in motor planning and cognitive processing. It has been shown that Pro-inflammatory cytokines and oxidative stress biomarkers could be increased in both ASD and ADHD. Several studies have been done to illustrate if vitamins and other dietary supplements are effective in treating and preventing ASD and ADHD. In this review, we aim to evaluate the effects of vitamins and other dietary supplements (e.g., melatonin, zinc supplements, magnesium supplements) on ASD and ADHD.

Elemental analysis of hair provides biomarkers of maternal hardship linked to adverse behavioural outcomes in 4-year-old children: The QF2011 Queensland Flood Study

BACKGROUND

Exposure to adverse experiences during pregnancy, such as a natural disaster, can modify development of the child with potential long-term consequences. Elemental hair analysis may provide useful indicators of cellular homeostasis and child health. The present study investigated (1) if flood-induced prenatal maternal stress is associated with altered hair elemental profiles in 4-year-old children, and (2) if hair elemental profiles are associated with behavioural outcomes in children.

METHODS

Participants were 75 children (39 boys; 36 girls) whose mothers were exposed to varying levels of stress due to a natural disaster (2011 Queensland Flood, Australia) during pregnancy. At 4 years of age, language development, attention and internalizing and externalizing problems were assessed and scalp hair was collected. Hair was analyzed by inductively coupled plasma mass spectrometry (ICP-MS) for 28 chemical elements.

RESULTS

A significant curvilinear association was found between maternal objective hardship and copper levels in boys, as low and high maternal objective hardship levels were associated with the highest hair copper levels. Mediation analysis revealed that low levels of maternal objective hardship and high levels of copper were associated with lower vocabulary scores. Higher levels of maternal objective hardship were associated with higher magnesium levels, which in turn were associated with attention problems and aggression in boys. In girls, high and low maternal objective hardship levels were associated with high calcium/potassium ratios.

CONCLUSION

Elemental hair analysis may provide a sensitive biomonitoring tool for early identification of health risks in vulnerable children.

Targeting PI3K by Natural Products: A Potential Therapeutic Strategy for Attention-deficit Hyperactivity Disorder

Attention-Deficit Hyperactivity Disorder (ADHD) is a highly prevalent childhood psychiatric disorder. In general, a child with ADHD has significant attention problems with difficulty concentrating on a subject and is generally associated with impulsivity and excessive activity. The etiology of ADHD in most patients is unknown, although it is considered to be a multifactorial disease caused by a combination of genetics and environmental factors. Diverse factors, such as the existence of mental, nutritional, or general health problems during childhood, as well as smoking and alcohol drinking during pregnancy, are related to an increased risk of ADHD. Behavioral and psychological characteristics of ADHD include anxiety, mood disorders, behavioral disorders, language disorders, and learning disabilities. These symptoms affect individuals, families, and communities, negatively altering educational and social results, strained parent-child relationships, and increased use of health services. ADHD may be associated with deficits in inhibitory frontostriatal noradrenergic neurons on lower striatal structures that are predominantly driven by dopaminergic neurons. Phosphoinositide 3-kinases (PI3Ks) are a conserved family of lipid kinases that control a number of cellular processes, including cell proliferation, differentiation, migration, insulin metabolism, and apoptosis. Since PI3K plays an important role in controlling the noradrenergic neuron, it opens up new insights into research on ADHD and other developmental brain diseases. This review presents evidence for the potential usefulness of PI3K and its modulators as a potential treatment for ADHD.

Zinc status in attention-deficit/hyperactivity disorder: a systematic review and meta-analysis of observational studies

Previous studies regarding the zinc status in attention-deficit/hyperactivity disorder (ADHD) yielded inconsistent results. Thus, the present meta-analysis was aimed to estimate the association between hair and serum/plasma zinc levels and ADHD. Online databases of Medline, EMBASE, and Scopus were searched up to October 2020 with no limitation in time and language. Weighted mean differences (WMDs) of hair and serum/plasma zinc levels were calculated using a random-effects model. Overall, 22 articles with 1280 subjects with ADHD and 1200 controls were included. The pooled effect size indicated that serum/plasma zinc levels in subjects with ADHD were not statistically different than their controls (WMD = − 1.26 µmol/L; 95% CI − 3.72, 1.20). Interestingly, the exclusion of one study from the analysis showed that people with ADHD significantly have lower circulating levels of zinc compared to their controls (WMD: − 2.49 µmol/L; 95% CI − 4.29, − 0.69). Also, the pooled effect size indicated that hair zinc levels in cases with ADHD were not statistically different than their controls (WMD = − 24.19 μg/g; 95% CI − 61.80, 13.42). Present meta-analysis raises the possibility that subjects with ADHD are prone to have declined levels of zinc levels. Based on current findings, screening the zinc levels in subjects with ADHD could be reasonable. Further well-designed studies are needed to clarify the role of zinc in the etiology of ADHD.

The effect of zinc supplementation in children with attention deficit hyperactivity disorder: A systematic review and dose-response meta‑analysis of randomized clinical trials

OBJECTIVE

The present systematic review and dose-response meta-analysis was conducted to quantify the efficacy of zinc supplementation on clinical symptoms of attention-deficit/hyperactivity disorder (ADHD) in children.

METHODS

Electronic databases including PubMed, Scopus, ISI web of science, and Google Scholar were searched until January 2021. Results were reported as standardized mean difference (SMD) with a 95% confidence interval (CI) using Hedges's adjusted g method.

RESULTS

six randomized clinical trials with 489 school-aged children were identified for the meta-analysis. Our findings showed a significant effect of zinc supplementation on ADHD total scores (SMD: -0.62 Hedges' g; 95% CI: -1.24 to -0.002, p = 0.04) but not in hyperactivity scores (SMD: -0.93 Hedges' g; 95% CI: -3.31 to 1.45, p = 0.44) and inattention scores (SMD: 0.21 Hedges' g; 95% CI: -0.09 to 0.51, p = 0.17) compared to the control group. Besides, the dose-response analysis did not find any significant non-linear association between zinc supplementation dosage or duration on ADHD total scores. The certainty of the evidence was rated moderate to very low for all outcomes.

CONCLUSION

Zinc supplementation may have beneficial effects in improving ADHD symptoms in children with ADHD. Future well-designed, large-scale randomized controlled trials are needed to establish the benefit of zinc supplementation for ADHD.

The effect of vitamin D and magnesium supplementation on the mental health status of attention-deficit hyperactive children: a randomized controlled trial

BACKGROUND

Attention-Deficit / Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder, characterized by varying severity in attention deficit and hyperactivity. Studies have shown deficiencies in the serum level of magnesium and vitamin D in people with ADHD. The aim of this study is to determine the effect of vitamin D and magnesium supplementation on mental health in children with ADHD.

METHODS

We conducted a randomized, double blind, placebo-controlled clinical trial of 66 children with ADHD. Participants were randomly allocated to receive both vitamin D (50,000 IU/week) plus magnesium (6 mg/kg/day) supplements (n = 33) or placebos (n = 33) for 8-weeks. Strengths and difficulties questionnaire was used to evaluate children's mental health at baseline and the end of the study.

RESULTS

After eight weeks of intervention, the serum levels of 25-hydroxy-vitamin D3 and magnesium increased significantly in the intervention group compared with the control group. Also, children receiving vitamin D plus magnesium showed a significant reduction in emotional problems (p = 0.001), conduct problems (p = 0.002), peer problems (p = 0.001), prosocial score (p = 0.007), total difficulties (p = 0.001), externalizing score (p = 0.001), and internalizing score (p = 0.001) compared with children treated with the placebo.

CONCLUSION

Vitamin D (50,000 IU/week) and magnesium (6 mg/kg/day) co-supplementation for a duration of 8-weeks could improve the behavioral function and mental health of children with ADHD. However, further well-designed studies with a larger sample size are needed.

TRIAL REGISTRATION

IRCT2016030326886N1 .

Zinc against COVID-19? Symptom surveillance and deficiency risk groups

A wide variety of symptoms is associated with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, and these symptoms can overlap with other conditions and diseases. Knowing the distribution of symptoms across diseases and individuals can support clinical actions on timelines shorter than those for drug and vaccine development. Here, we focus on zinc deficiency symptoms, symptom overlap with other conditions, as well as zinc effects on immune health and mechanistic zinc deficiency risk groups. There are well-studied beneficial effects of zinc on the immune system including a decreased susceptibility to and improved clinical outcomes for infectious pathogens including multiple viruses. Zinc is also an anti-inflammatory and anti-oxidative stress agent, relevant to some severe Coronavirus Disease 2019 (COVID-19) symptoms. Unfortunately, zinc deficiency is common worldwide and not exclusive to the developing world. Lifestyle choices and preexisting conditions alone can result in zinc deficiency, and we compile zinc risk groups based on a review of the literature. It is also important to distinguish chronic zinc deficiency from deficiency acquired upon viral infection and immune response and their different supplementation strategies. Zinc is being considered as prophylactic or adjunct therapy for COVID-19, with 12 clinical trials underway, highlighting the relevance of this trace element for global pandemics. Using the example of zinc, we show that there is a critical need for a deeper understanding of essential trace elements in human health, and the resulting deficiency symptoms and their overlap with other conditions. This knowledge will directly support human immune health for decreasing susceptibility, shortening illness duration, and preventing progression to severe cases in the current and future pandemics.

Minerals in Pregnancy and Their Impact on Child Growth and Development

During pregnancy, women undergo metabolic and physiological changes, and their needs are higher, to maintain growth and development of the fetus. If the nutritional status of the expectant mother is not satisfactory, some maternal and neonatal complications can occur. In the second and third trimester of pregnancy, there is a reserve of nutrients in the fetus that can be utilized after birth; thereby, children present an accelerated growth in the first years of life, which is a proven response to the available nutrition pattern. However, if such a pattern is insufficient, there will be deficits during development, including brain function. Therefore, despite many recent published works about gestational nutrition, uncertainties still remain on the mechanisms of absorption, distribution, and excretion of micronutrients. Further elucidation is needed to better understand the impacts caused either by deficiency or excess of some micronutrients. Thus, to illustrate the contributions of minerals during prenatal development and in children, iodine, selenium, iron, zinc, calcium, and magnesium were selected. Our study sought to review the consequences related to gestational deficiency of the referred minerals and their impact on growth and development in children born from mothers with such deficiencies

Possible Associations of Disturbed Neurometals and Ammonia with Glycaemic Control in Type 1 Diabetic Children with Attention Deficit Hyperactivity Disorder

The chronicity of type 1 diabetes mellitus (T1DM) is reported to be associated with various psychological disorders. The current study aimed to evaluate the levels of serum ammonia and various neurometals (zinc, copper, and magnesium) in patients with T1DM with and without ADHD and to correlate their levels with glycaemic status. A prospective case-control study was conducted with 60 diabetic children with T1DM (allocated into a group of 20 patients with a diagnosis of ADHD and a group of 40 patients without ADHD) who were comparable to 60 matched controls. Assays of glucose, glycated haemoglobin (HbA1c), ammonia, zinc, copper, and magnesium were performed. Overall, ammonia and copper levels were significantly higher in the diabetic patients especially those with ADHD than in the control group (p ˂ 0.05 for all). The calculated copper/zinc ratio was significantly higher in the diabetic patient group than in the control group and higher in diabetic children with ADHD than in diabetic children without ADHD (p ˂ 0.05 for all). Diabetic children had significantly lower magnesium levels than the controls (p ˂ 0.05), but no significant difference between the diabetic subgroups was detected. A positive correlation between glycaemic control (HbA1c %) and ammonia level was found in the diabetic group and subgroups, and a positive correlation was found between HbA1c % and the Cu/Zn ratio in diabetic children with ADHD (p ˂ 0.05 for all). The current study confirms an association of elevated ammonia and copper/zinc ratio with poor glycaemic control and ADHD development among children with T1DM.

Magnesium, Iron, Zinc, Copper and Selenium Status in Attention-Deficit/Hyperactivity Disorder (ADHD)

In this study, we critically review the literature concerning the relation of Mg, Fe, Zn, Cu and Se and attention-deficit/hyperactivity disorder (ADHD). Elemental status is estimated using peripheral blood parameters, hair, urine, daily intake and response to supplementation. The observed associations between concentration levels of the elements Mg, Fe, Zn, Cu and Se and ADHD symptoms are contradictory. This is partly due to the heterogeneity and complexity of the disorder. As a trend, lower ferritin and zinc levels can be observed. However, this correlation is not causative, as illustrated by placebo-controlled trials reporting conflicting evidence on the efficacy of supplementation. Well-defined studies on changes in concentration levels of the elements in relation to ADHD symptoms before and after treatment with therapeutics it will be possible to shed more light on the significance of these elements in this behavioral disorder. The discussion on whether a change in concentration of an element is cause or consequence of ADHD is not within the scope of this article.

The Role of Lead, Manganese, and Zinc in Autism Spectrum Disorders (ASDs) and Attention-Deficient Hyperactivity Disorder (ADHD): a Case-Control Study on Syrian Children Affected by the Syrian Crisis

Autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) are two developmental disorders that affect children worldwide, and are linked to both genetic and environmental factors. This study aims to investigate the levels of lead, manganese, and zinc in each of ASD, ADHD, and ASD with comorbid ADHD in Syrian children born or grown during the Syrian crisis. Lead and manganese were measured in the whole blood, and zinc was measured in the serum in 31 children with ASD, 29 children with ADHD, and 11 children with ASD with comorbid ADHD (ASD-C) compared with 30 healthy children, their ages ranged between 3 and 12 years. Blood lead levels were higher in the groups of ASD-C (245.42%), ASD (47.57%), and ADHD (14.19%) compared with control. Lead levels were significantly higher in children with ASD in the age of 5 or less compared with control, and they were also higher in the male ASD compared with females (P = 0.001). Blood manganese levels were lower in the groups of ASD-C (10.35%), ADHD (9.95%, P = 0.026), and ASD (9.64%, P = 0.046). However, serum zinc levels were within the reference range in all groups of study. Lead and manganese were positively correlated with each other (P = 0.01). Lead increase and manganese decrease may associate with the incidence of ASD, ADHD, or the co-occurrence of both of them together. Further studies are needed to examine the relationship between metal levels and the co-occurrence of ASD and ADHD together.

Hair trace element concentrations in autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD)

BACKGROUND

The existing data demonstrate that alteration of trace element and mineral status in children with neurodevelopmental disorders including ASD and ADHD. However, comparative analysis of the specific patterns of trace element and mineral metabolism in children with ASD and ADHD was not performed. Therefore, the primary objective of the present study was to assess hair trace element and mineral levels in boys with ADHD, ASD, as well as ADHD with ASD.

METHODS

Boys with ADHD (n = 52), ASD (n = 53), both ADHD and ASD (n = 52), as well as neurotypical controls (n = 52) were examined. Hair analysis was performed using inductively-coupled plasma mass-spectrometry.

RESULTS

The obtained data demonstrate that hair Co, Mg, Mn, and V levels were significantly reduced in children with ADHD and ASD, and especially in boys with ADHD + ASD. Hair Zn was found to be reduced by 20% (p = 0.009) only in children with ADHD + ASD as compared to healthy controls. Factor analysis demonstrated that ASD was associated with significant alteration of hair Co, Fe, Mg, Mn, and V levels, whereas impaired hair Mg, Mn, and Zn content was also significantly associated with ADHD. In regression models hair Zn and Mg were negatively associated with severity of neurodevelopmental disorders. The revealed similarity of trace element and mineral disturbances in ASD and ADHD may be indicative of certain similar pathogenetic features.

CONCLUSION

The obtained data support the hypothesis that trace elements and minerals, namely Mg, Mn, and Zn, may play a significant role in development of both ADHD and ASD. Improvement of Mg, Mn, and Zn status in children with ASD and ADHD may be considered as a nutritional strategy for improvement of neurodevelopmental disturbances, although clinical trials and experimental studies are highly required to support this hypothesis.

ICP-MS Assessment of Hair Essential Trace Elements and Minerals in Russian Preschool and Primary School Children with Attention-Deficit/Hyperactivity Disorder (ADHD)

The objective of the present study was to investigate the relationship between hair essential trace element and mineral content and ADHD in preschool (4-6 years old) and primary school children (6-10 years old) in relation to age and gender. Hair essential trace element and mineral content in 90 Russian children with ADHD and 90 age- and gender-matched neurotypical controls were assessed using inductively coupled plasma mass-spectrometry after microwave digestion. The obtained data demonstrate that hair Co, Cu, Mn, Si, and Zn contents in ADHD children was significantly reduced by 18%, 10%, 27%, 16%, and 19% as compared to the control values, respectively. The most significant decrease in children with ADHD was observed for hair Mg levels, being 29% lower than those in neurotypical children. After adjustment for age and gender, the observed difference in hair element content was more characteristic for preschool children and girls, respectively. Multiple linear regression analysis demonstrated that in a crude model (hair element levels as predictors), only hair Zn content was significantly inversely associated with ADHD (β = - 0.169; p = 0.025). Adjustment for anthropometric parameters (model 2) did not increase the predictive ability of the model, although it improved the association between hair Zn and ADHD in children (β = - 0.194; p = 0.014). Hypothetically, the observed alterations may at least partially contribute to neurobehavioral disturbances in children with ADHD. Moreover, the results of the present study raise the question about the potential benefits of Zn and Mg supplementation in children with ADHD. However, further detailed studies are required to investigate micronutrient deficiencies in ADHD.

Neurodevelopmental disorders: Metallomics studies for the identification of potential biomarkers associated to diagnosis and treatment

BACKGROUND

Diagnosis and treatment of complex diseases such as Neurodevelopmental Disorders (NDDs) can be resolved through the identification of biomarkers. Metallomics (research on biometals) and metallomes (metalloproteins/metalloenzymes/chaperones) along with genomics, proteomics and metabolomics, can contribute to accelerate and improve this process.

AIM

This review focused on four NDDs pathologies (Schizophrenia, SZ; Attention Deficit Hyperactivity Disorder, ADHD; Autism, ADS; Epilepsy), and we reported, for the first time, different studies on the role played by the principal six essential trace elements (Cobalt, Co; Copper, Cu; Iron, Fe; Manganese, Mn; Selenium, Se; Zinc, Zn) that can influence diagnosis/treatment.

RESULTS

in light of the literature presented, based on meta-analyses, we suggest that Zn (glutamatergic neurotransmission, inflammation, neurodegeneration, autoimmunity alterations), could be a potential diagnostic biomarker associated to SZ. Moreover, considering the single association studies going in the same direction, increased Cu (catecholamine alterations, glucose intolerance, altered lipid metabolism/oxidative stress) and lower Fe (dopaminergic dysfunctions) levels were associated with a specific negative symptomatology. Lower Mn (lipid metabolism/oxidative stress alterations), and lower Se (metabolic syndrome) were linked to SZ. From the meta-analyses in ADHD, it is evidenced that Fe (and ferritin in particular), Mn, and Zn (oxidative stress dysfunctions) could be potential diagnostic biomarkers, mainly associated to severe hyperactive or inattentive symptoms; as well as Cu, Fe, Zn in ADS and Zn in Epilepsy. Fe, Zn and Mn levels seem to be influenced by antipsychotics treatment in SZ; Mn and Zn by methylphenidate treatment in ADHD; Cu and Zn by antiepileptic drugs in Epilepsy.

CONCLUSIONS

Although there is controversy and further studies are needed, this work summarizes the state of art of the literature on this topic. We claim to avoid underreporting the impact of essential trace elements in paving the way for biomarkers research for NDDs.

Toward 'element balance' in ADHD: an exploratory case control study employing hair analysis

Background: Head hair analysis has been used for decades to clarify mineral relationships to symptoms of ADHD, but there is little consensus among findings. We sought to explore 33 hair element concentrations and their 528 calculated ratios among two groups of boys, one with ADHD and one without.Method: 107 boys aged 7-12 years were recruited; 55 with ADHD and 52 non-ADHD Controls. Hair minerals were compared using Mann-Whitney U tests, p<0.01 was used for significance. Dietary data were obtained using a 138 item food frequency questionnaire (FFQ).Results: There were three group differences on individual elements: bismuth/Bi: 8 fold higher in ADHD, chromium/Cr: 15% lower in ADHD and germanium/Ge: 11% lower in ADHD, Cr level being the strongest predictor of ADHD symptoms. We found thirty significant group differences in element ratios, two thirds involving Bi and eight of these showing that as ADHD severity increased, the ratios with Bi as the denominator decreased (r ranging from -0.263 to -0.433, p<0.01). From the FFQ, tinned fruit was consumed more often in the ADHD group. Hair arsenic levels were somewhat elevated across both ADHD and Control groups.Discussion: While element 'imbalance' appears to be associated with ADHD, we did not replicate any previous study results of group differences on individual elements. We have raised the possibility that the ratios may be far more important than any one individual element in better elucidating the effects that minerals may have on the pathogenesis of ADHD. These are cautionary findings requiring replication.

Blood and hair zinc levels in children with attention deficit hyperactivity disorder: A meta-analysis

We summarized the observational studies on the correlation between zinc and attention deficit hyperactivity disorder (ADHD) since 1986, extracted relevant data for meta-analysis to determine the relationship between zinc and ADHD. We searched PubMed, Scopus, Cochrane Library, EMBASE (included EMBASE and Medline), Web of Science and Clinical Trials.gov databases from inception to April 8, 2019. We assessed the blood zinc, hair zinc and ADHD by combined the standardized mean difference (SMD) and 95% confidence interval (CI). Statistical analysis was performed using Stata 14.0. We included 11 studies for meta-analysis. Of these, 8 studies comprising 1311 participants reported blood zinc and 3 studies comprising 206 participants reported hair zinc. The zinc levels in blood (SMD: -0.91, 95% CI: -1.88-0.07, P(SMD) < 0.068), and hair (SMD: 1.42, 95% CI: -4.49-7.33, P(SMD) = 0.638) not significantly compare ADHD with controls. Nevertheless, high heterogeneity (I² > 97.3%) emerged among the included studies. The subgroup analysis showed that the heterogeneity of samples >100 group was significantly reduced. The sensitivity analysis found that the results changed significantly after excluding the only cross-sectional study. In conclusion, our meta-analysis showed that there was no statistically significant difference in blood zinc and hair zinc levels between ADHD children and adolescents compared with healthy children and adolescents.

Magnesium Status in Children with Attention-Deficit/Hyperactivity Disorder and/or Autism Spectrum Disorder

Objective:

The objective of this study was to assess serum, hair, and urinary magnesium (Mg) levels in children with attention-deficit/ hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and both ASD and ADHD to reveal potential interactive effects.

Methods:

A total of 148 boys aged 4–9 years old were enrolled in this study, including 44 children with ADHD, 40 pediatric patients with ASD, 32 patients with both ADHD and ASD, as well as 32 healthy neurotypical children. Hair, serum, and urinary Mg levels were assessed using inductively-coupled plasma mass spectrometry (ICP-MS). Laboratory quality control was performed using certified reference materials of human hair, plasma, and urine.

Results:

No significant group difference in serum Mg levels was observed. Mg content in hair was found to be reduced in children with ADHD and ADHD+ASD compared to that in healthy controls by 11% and 15%, respectively. Urinary Mg levels in children with ADHD+ASD exceeded the control, ADHD, and ASD values by 51, 76, and 65%, respectively. Factorial analysis revealed significant contribution of ADHD to hair and urinary Mg levels. Multiple regression analysis demonstrated that hair and urinary Mg levels were considered as significant predictors of neurodevelopmental disorder complexity.

Conclusion:

We propose that impaired Mg status may provide a link between ADHD and ASD.

Magnesium status and attention deficit hyperactivity disorder (ADHD): A meta-analysis

Current research suggests conflicting evidence surrounding the association between serum magnesium levels and the diagnosis of attention deficit hyperactivity disorder (ADHD). This systematic review and meta-analysis aims to explore, summarize and quantify the published literature addressing this topic. We conducted an exhaustive literature search on Scopus and PubMed for all the relevant observational studies published up to August 2018. A meta-analysis using a random-effects model was used to summarize the overall association between serum magnesium level and ADHD from the available data. We identified seven studies which reported the mean and standard deviation (SD) of magnesium concentration in both ADHD and control groups. The random-effects meta-analysis showed that subjects with ADHD had 0.105 mmol/l (95% CI: -0.188, -0.022; P < 0.013) lower serum magnesium levels compared with to their healthy controls. Moreover, we observed striking and statistically significant heterogeneity among the included studies (I² = 96.2%, P = 0.0103). The evidence from this meta-analysis supports the theory that an inverse relationship between serum magnesium deficiency and ADHD exists. High heterogeneity amongst the included studies suggests that there is a residual need for observational and community-based studies to further investigate this issue.

Can we predict treatment response in children with ADHD to a vitamin-mineral supplement? An investigation into pre-treatment nutrient serum levels, MTHFR status, clinical correlates and demographic variables

BACKGROUND

Intent-to-treat analyses from a randomized controlled trial showed significant between-group differences favouring micronutrient treatment on the Clinical Global Impression-Improvement, but no group differences on clinician, parent and teacher ratings of overall ADHD symptoms. There was an advantage of micronutrients over placebo in improving overall function, emotional regulation, aggression, and reducing impairment as well as improving inattention based on clinician but not parent observation. No group differences were observed on hyperactive-impulsive symptoms. We investigated predictors of response defined by pre-treatment variables.

METHOD

We conducted analyses of data from a clinical trial of children (7-12 years) with ADHD, whereby participants were randomized to receive micronutrients or placebo for 10 weeks followed by a 10 week open-label (OL) phase. We included only children who had been exposed to micronutrients for a full 10 week period and demonstrated satisfactory adherence, either in RCT phase (n = 40) or OL phase (those who received placebo during RCT phase; n = 31). Seven outcomes were examined: change in ADHD symptoms (clinician/parent), ADHD responder, overall responder, change in mood, change in functioning, and change in aggression. Demographic, developmental variables, current clinical and physical characteristics, MTHFR genotype at two common variants, and pre-treatment serum/plasma levels (vitamin D, B₁₂, folate, zinc, copper, iron, ferritin, potassium, calcium, magnesium, and homocysteine) were all considered as putative predictors.

RESULTS

Substantial nutrient deficiencies pre-treatment were observed only for vitamin D (13%) and copper (15%), otherwise most children entered the trial with nutrient levels falling within expected ranges. Regression analyses showed varying predictors across outcomes with no one predictor being consistently identified across different variables. Lower pre-treatment folate and B₁₂ levels, being female, greater severity of symptoms and co-occurring disorders pre-treatment, more pregnancy complications and fewer birth problems were identified as possible predictors of greater improvement for some but not all outcome measures although predictive values were weak. Lower IQ and higher BMI predicted greater improvement in aggression.

CONCLUSIONS

This study replicates Rucklidge et al. (2014b) showing the limited value of using serum nutrient levels to predict treatment response although we cannot rule out that other non-assayed nutrient levels may be more valuable. Additionally, no specific demographic or clinical characteristics, including MTHFR genetic status, were identified that would preclude children with ADHD from trying this treatment approach.

Significantly lower serum and hair magnesium levels in children with attention deficit hyperactivity disorder than controls: A systematic review and meta-analysis

The pathophysiology of attention deficient hyperactivity disorder (ADHD) is still obscure. Some studies have discussed that magnesium levels are lower in the serum and erythrocytes of children with ADHD. However, these findings are controversial. The aim of our study is to identify whether magnesium levels are in fact lower in children with ADHD. We conducted a thorough search of the literature and examined the connection between magnesium insufficiency and ADHD. A total of twelve studies were included into the current meta-analysis. The results of our meta-analysis found that peripheral blood magnesium levels, either in plasma, serum, or whole blood, of children diagnosed with ADHD were significantly lower than those in controls (k = 8, Hedges' g = -0.547, 95% CI = -0.818 to -0.276, p < .001). The subgroup meta-analysis with serum sample sources also suggested that peripheral serum magnesium levels of children diagnosed with ADHD were significantly lower than those in controls (k = 6, Hedges' g = -0.733, 95% CI = -0.911 to -0.555, p < .001). The subgroup meta-analysis focusing on subjects with ADHD diagnosed by definite diagnostic criteria also suggested significantly lower peripheral serum magnesium levels in ADHD children than those in controls (k = 4, Hedges' g = -0.780, 95% CI = -0.985 to -0.574, p < .001). We also noted that magnesium levels in the hair of children diagnosed with ADHD were significantly lower than those in controls (k = 4, Hedges' g = -0.713, 95% CI = -1.359 to -0.067, p = .031). In this meta-analysis, we found that children diagnosed with ADHD have lower serum and hair magnesium levels than children without ADHD. Further study may be needed to investigate the behavioral influence on ADHD due to lower magnesium levels, the association between brain and serum magnesium levels, and the effects brought about by larger longitudinal cohort studies.

Dietary Intake and Content of Cu, Mn, Fe, and Zn in Selected Cereal Products Marketed in Poland

This paper aims to verify whether cereal products are a good source of Cu, Mn, Fe, and Zn in the diets of Poles. The study material comprised of 445 cereal products including baked goods, breakfast cereals and groats, pasta, and rice. Products that required culinary treatment (pasta, groats, rice) were boiled in drinking quality water as recommended by the producer. The content of Cu, Mn, Fe, and Zn was determined by using the FAAS method. The average content of microelements in the analyzed products can be represented as Fe (17.9 mg kg-1 ± 10.3) > Zn (12.4 mg kg-1 ± 5.2) > Mn (9.6 mg kg-1 ± 6.7) > Cu (3.9 mg kg-1 ± 2.9). Considering the daily requirement of the analyzed minerals among adult Poles, it was determined that cereal products supply 58% RDA Cu, 61% AI Mn (men)-78% AI Mn (women), 19% RDA Fe (women)-34% RDA Fe (men), and 16% RDA Zn (men)-22% RDA Fe (women). Baked goods account for as much as about 90% of all Cu, Mn, Fe, and Zn consumed as cereal products in a daily diet. Based on the results, it can be concluded that cereal products are the main source of Cu, Mn, Fe, and Zn in the diets of Poles. In connection with low assimilability of minerals, they should not be considered the fundamental source of those microelements in the diets of Poles.

A Gut Feeling: A Hypothesis of the Role of the Microbiome in Attention-Deficit/Hyperactivity Disorders

Attention-deficit/hyperactivity disorder (ADHD) is a neurologic disorder characterized by hyperactivity/impulsivity and/or inattentiveness, with genetic and environmental factors contributing to the disorder. With the growing recognition of the microbiome’s role in many neurological disorders, the authors propose that it may also be implicated in ADHD. Here, we describe several evolving areas of research to support this hypothesis. First, a unique composition of gut bacteria has been identified and linked to behaviors in ADHD. Second, our research found an increased incidence of 2 gastrointestinal symptoms (constipation and flatulence) in children with ADHD, as compared to controls. Finally, emerging data may be interpreted to suggest that immune dysregulation in ADHD be associated with an altered microbiome, low-grade inflammation, and gastrointestinal dysfunction. Although more studies are needed to elucidate exact mechanisms and causality, we propose that an altered microbiome, gastrointestinal symptoms, and immune dysregulation may be associated with the ADHD phenotypes.

Trace elements concentrations in squids consumed in Shandong Province China and their associated risks to the human health

Determination of ten metal levels in 160 squid samples caught from offshore and the oceanic fishing locations by ICP-MS was made. The mean metal concentration in the squid muscles decreasing in the order of: Zn, Fe, Cu, As, Mn, Se, Cd, Pb, Cr and Ni. Metal concentrations in the squids were assessed for human uses according to provisional tolerable weekly intake (PTWI) and provisional tolerable daily intake (PTDI)·The estimated hazard quotients for the individual metals from squids were found in accordance to the following sequence: As > Cd > Cu > Se > Cr > Zn > Pb > Fe > Mn > Ni, with the greatest hazard upon human health coming primarily from As (1.34 < HQ < 1.73 in the Loliginidae from two offshore sampling sites and the Humboldt squid from the eastern Pacific Ocean). In regards to the heavy metal pollution of the coastal sea areas, the squids captured from offshore sites might pose a higher potential health risk to consumers compared to those from the ocean.