An association between vitamin D and attention deficit hyperactivity disorder (ADHD) has been proposed by several researchers in recent years; however, the investigations have led to inconsistent results. The present study was conducted to summarize the published observational data on the relation between vitamin D status and the likelihood of ADHD. Online databases, including PubMed, the ISI Web of Science, Google Scholar, and Scopus, were checked up to June 2017 for relevant observational studies. A random-effects model was incorporated to summarize the study results. Out of 2770 retrieved articles, 13 observational studies (9 case-control or cross-sectional studies and 4 prospective studies) were eligible for inclusion in the systematic review and meta-analysis. Analysis of the 10,334 children and adolescents who attended the 9 case-control or cross-sectional studies revealed that children with ADHD have lower serum concentrations of 25-hydroxyvitamin D than do healthy children (weighted mean difference: -6.75 ng/mL; 95% CI: -9.73, -3.77 ng/mL; I2 = 94.9%]. Five case-control studies reported the OR for developing ADHD based on vitamin D status; the meta-analysis of their data revealed that lower vitamin D status is significantly associated with the likelihood of ADHD (OR: 2.57; 95% CI: 1.09, 6.04; I2 = 84.3%). Furthermore, the meta-analysis of prospective studies conducted in 4137 participants indicated that perinatal suboptimal vitamin D concentrations are significantly associated with a higher risk of ADHD in later life (RR: 1.40; 95% CI: 1.09, 1.81; I2 = 0.0%). It should be noted that the association found in prospective studies was sensitive to one of the included investigations. The present review provides evidence supporting the relation between vitamin D deficiency and ADHD. However, the overall effect sizes are small, and therefore the association should be considered equivocal at this time. Further prospective cohort studies and community-based intervention trials are highly recommended to better elucidate the causal association.

Previous studies have led to conflicting results regarding the effect of hesperidin supplementation on cardiometabolic markers. This study aimed to evaluate the efficacy of hesperidin supplementation on lipid profile and blood pressure through a systematic review and meta‐analysis of randomized controlled trials (RCTs). PubMed, Web of Science, Scopus, and Google Scholar, as well as the reference lists of the identified relevant RCTs, were searched up to May 2018. Effect sizes were pooled by using the random effects model. Ten RCTs (577 participants) were eligible to be included in the systematic review. The meta‐analysis revealed that hesperidin supplementation had no effect on serum total cholesterol (weighted mean difference [WMD] = −1.04 mg/dl; 95% confidence interval [CI]: −5.65, 3.57), low‐density lipoprotein cholesterol (WMD = −1.96 mg/dl; 95% CI [−7.56, 3.64]), high‐density lipoprotein cholesterol (WMD = 0.16 mg/dl; 95% CI [−1.94, 2.28]), and triglyceride (WMD = 0.69 mg/dl; 95% CI [−5.91, 7.30]), with no significant between‐study heterogeneity. Hesperidin supplement also had no effect on systolic (WMD = −0.85 mmHg; 95% CI [−3.07, 1.36]) and diastolic blood pressure (WMD = −0.48 mmHg; 95% CI [−2.39, 1.42]). Hesperidin supplementation might not improve lipid profile and blood pressure. Future well‐designed trials are still needed to confirm these results.

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Background The dietary approaches to stop hypertension (DASH) diet has several components that might improve attention deficit hyperactivity disorder (ADHD) symptoms. This randomized controlled clinical trial (RCT) aimed to investigate the effect of the DASH diet on ADHD symptoms in children, for the first time.Methods Children (aged 6-12 years) with ADHD were randomized to receive a DASH or a control diet for 12 weeks. The severity of ADHD symptoms [determined by abbreviated 10-item Conner's scale (ACS), 18-item Swanson, Nolan and Pelham (SNAP-IV) scale and strengths and difficulties questionnaire (SDQ)], as well as dietary intakes, physical activity, and anthropometric measurements, were assessed every four weeks. The symptom scores provided by teachers, parents, and children were compared between the two groups, in multivariable-adjusted models.Results A total of 80 children completed the study. After adjustment for age, sex, energy intake, and baseline values significant group effects were observed for parent-reported ACS score, childrenreported emotional symptoms and peer relationship problems, and parent-reported scores of prosocial behaviors based on the SDQ scale (Pgroup<0.05). Significant group*time effects were indicated in teacher-reported ACS score, teacher-reported Hyperactivity and impulsivity, and parentreported combined score based on SNAP-IV, and teacher/child-reported scores for hyperactivity, parent and teacher-reported scores of emotional symptoms, peer relationship problems, and prosocial behavior, and also teacher/parent/child-reported total SDQ score (Pgroup*time<0.05). The adjusted mean in teacher/parent-reported ACS scores, teacher/parent/child-reported hyperactivity, and total SDQ scores, teacher-reported emotional symptoms, conduct problems, peer relationship problems, and prosocial behaviors assessed by the SDQ were significantly improved in the DASH compared to the control group (P<0.05).Conclusions Adherence to the DASH diet might beneficially improve ADHD symptoms. Further RCTs with more follow-up period which include participants from both sexes are needed to confirm these results.Trial registration: The trial was registered in the Iranian registry of clinical trials (registration code:

Background The dietary approaches to stop hypertension (DASH) diet has several components that might improve attention deficit hyperactivity disorder (ADHD) symptoms. This randomized controlled clinical trial (RCT) aimed to investigate the effect of the DASH diet on ADHD symptoms in children, for the first time.Methods Children (aged 6-12 years) with ADHD were randomized to receive a DASH or a control diet for 12 weeks. The severity of ADHD symptoms [determined by abbreviated 10-item Conner’s scale (ACS), 18-item Swanson, Nolan and Pelham (SNAP-IV) scale and strengths and difficulties questionnaire (SDQ)], as well as dietary intakes, physical activity, and anthropometric measurements, were assessed every four weeks. The symptom scores provided by teachers, parents, and children were compared between the two groups, in multivariable-adjusted models.Results A total of 80 children completed the study. After adjustment for age, sex, energy intake, and baseline values significant group effects were observed for parent-reported ACS score, children-reported emotional symptoms and peer relationship problems, and parent-reported scores of prosocial behaviors based on the SDQ scale (Pgroup<0.05). Significant group*time effects were indicated in teacher-reported ACS score, teacher-reported Hyperactivity and impulsivity, and parent-reported combined score based on SNAP-IV, and teacher/child-reported scores for hyperactivity, parent and teacher-reported scores of emotional symptoms, peer relationship problems, and prosocial behavior, and also teacher/parent/child-reported total SDQ score (Pgroup*time<0.05). The adjusted mean in teacher/parent-reported ACS scores, teacher/parent/child-reported hyperactivity, and total SDQ scores, teacher-reported emotional symptoms, conduct problems, peer relationship problems, and prosocial behaviors assessed by the SDQ were significantly improved in the DASH compared to the control group (P<0.05).Conclusions Adherence to the DASH diet might beneficially improve ADHD symptoms. Further RCTs with more follow-up period which include participants from both sexes are needed to confirm these results.Trial registration: The trial was registered in the Iranian registry of clinical trials (registration code: IRCT20130223012571N6).