Observational studies have indicated an inverse association between vitamin D levels and the risk of diabetes, yet evidence from population interventions remains inconsistent. PubMed, EMBASE, Cochrane Library and ClinicalTrials.gov were searched up to September 2017. Data from studies regarding serum 25(OH)D, fasting blood glucose (FBG), hemoglobin A1c (HbA1c), fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were pooled. Twenty studies (n = 2703) were included in the meta-analysis. Vitamin D supplementation resulted in a significant improvement in serum 25(OH)D levels (weighted mean difference (WMD) = 33.98; 95%CI: 24.60–43.37) and HOMA-IR (standardized mean difference (SMD) = −0.57; 95%CI: −1.09~−0.04), but not in other outcomes. However, preferred changes were observed in subgroups as follows: short-term (WMD_FBG = −8.44; 95%CI: −12.72~−4.15), high dose (WMD_FBG = −8.70; 95%CI: −12.96~−4.44), non-obese (SMD_{Fasting insulin} = −1.80; 95%CI: −2.66~−0.95), Middle Easterners (WMD_FBG = −10.43; 95%CI: −14.80~−6.06), baseline vitamin D deficient individuals (WMD_FBG = −5.77; 95%CI: −10.48~−1.05) and well-controlled HbA1c individuals (WMD_FBG = −4.09; 95%CI: −15.44~7.27). Vitamin D supplementation was shown to increase serum 25(OH)D and reduce insulin resistance effectively. This effect was especially prominent when vitamin D was given in large doses and for a short period of time, and to patients who were non-obese, Middle Eastern, vitamin D deficient, or with optimal glycemic control at baseline.

Objective: Hashimoto’s thyroiditis (HT) is the most common type of thyroid disease and can cause many different manifestations. The local symptoms of HT are an under-studied area of research. Therefore, the purpose of this study was to investigate the local symptoms of HT and their prevalence.Methods: A systematic review was performed to find articles in PubMed that discuss the local symptoms of HT. Relevant vocabulary terms and key terms included: autoimmune thyroid disease (AITD), hyperthyroidism, hypothyroidism, neck, throat, pharynx, airway, esophagus, breathe, swallow, globus, sleep apnea, symptoms, and quality of life. Two investigators independently screened the eligible studies.Results: A total of 54 articles fulfilled the inclusion criteria. Of these, 25 were clinical studies, 24 were case reports, and five were reviews. These clinical studies and case reports included a total of 2660 HT patients. There were eight local symptoms related to HT: neck pain (0.02%~16%), voice changes (7%~30%), throat discomfort (20%~43.7%), shortness of breath (28%~50%), dysphagia (29%), goiter-related symptoms (69.44%), sleep apnea, and generally defined compressive symptoms. Due to the use of different outcome measures among all the studies, a meta-analysis of the data could not be performed.Conclusion: Goiter symptoms, which are an item on the ThyPRO scales, are the most frequent local symptoms in HT patients, and include neck pain, voice changes, throat discomfort, and dysphagia. These local symptoms should be identified in the clinic and included in the early diagnosis and management of HT, as well as evaluated further to understand their relevance in the pathogenesis of HT.

Yingyangbao (YYB) is a nutrient-dense complementary food supplement for infants and young children in China. There has been considerable interest and research on the potential effects of YYB on hematological and anthropometric outcomes in China, but limited effort has been made to consolidate and synthesize the evidence to inform the research and policy agendas. Eight English databases and three Chinese databases were searched from January 2001 to June 2019 to identify YYB intervention studies. A total of 32 quasi-experimental, post-only, concurrent-control studies or pre-post studies were identified, and 26 were included in the meta-analyses. A pooled analysis of post-only studies with concurrent-control determined that YYB was associated with an increase of 4.43 g/L (95% confidence interval (CI) 1.55, 7.30) hemoglobin concentration, 2.46 cm (CI 0.96, 3.97) in height, and 0.79 kg (CI 0.25, 1.32) weight in infants and young children. YYB was also associated with reductions in the prevalence of anemia (risk ratio (RR) = 0.55; 95% CI: 0.45, 0.67), stunting (RR = 0.60; 95% CI: 0.44, 0.81), and underweight (RR = 0.51; 95% CI: 0.39, 0.65). Overall, YYB was found to be associated with improved hematological and anthropometric indicators among infants and young children in China; however, randomized trials are needed to causally assess the efficacy of YYB due to the inherent risk of bias in existing quasi-experimental studies; rigorous implementation and cost-effectiveness evaluations are also needed.

Despite the importance of vitamin D in early stages of life, data are lacking on the levels of vitamin D intake and serum 25-hydroxyvitamin D (25-(OH)D) among Chinese school-age children. The aims of this study were to investigate the vitamin D intake and serum 25-(OH)D concentration of children aged 7 to 12 years in China, and to measure the associations between vitamin D status and children’s growth and development parameters. We obtained data on vitamin D intake, serum 25-(OH)D concentration, and anthropometric measurements from a cross-sectional study on school-aged children in China. Multiple linear regression and multivariable logistic regression analyses assessed the associations mentioned above. A total of 563 children (9.5 ± 1.6 years) from six areas of China were included. Among them, 86.1% had a vitamin D intake below the recommended nutrient intake (10 μg/day), and 54.7% had vitamin D deficiency (serum 25-(OH)D <15 ng/mL). We also found that high vitamin D intake was inversely associated with the risk of vitamin D deficiency (OR = 0.836, 95% confidence interval: 0.713, 0.980), and serum 25-(OH)D concentration was positively associated with the intelligence score and body mass index-for-age Z-score (BAZ) (p < 0.05). Insufficient vitamin D intake and serum 25-(OH)D are prevalent among Chinese school-aged children. A negative association was observed between vitamin D intake and the risk of vitamin D deficiency. Moreover, vitamin D status was positively associated with intelligence and BAZ, which await confirmation in future studies.