Background: The contribution of vitamin D to thyroid disorders has received paramount attention; however, results are mixed. Hence, we designed a systematic review and meta-analysis to obtain a definitive conclusion. Methods: The search included PubMed, ISI Web of Science, Scopus, and Google Scholar databases up to March 2021 to collect available papers reporting the relationship between serum levels of vitamin D and thyroid disorders. The pooled effect was reported as weighted mean difference (WMD) and 95% confidence interval (CI). Results: Out of 6123 datasets, 42 were eligible to get into this systematic review and meta-analysis. Serum vitamin D was markedly lower in autoimmune thyroid diseases (AITD) (WMD − 3.1 ng/dl; 95% CI, − 5.57 to − 0.66; P = 0.013; I² = 99.9%), Hashimoto’s thyroiditis (HT) (WMD − 6.05 ng/dl; 95% CI, − 8.35 to − 3.75; P < 0.001; I² = 91.0%) and hypothyroidism patients (WMD − 13.43 ng/dl; 95% CI, − 26.04 to − 0.81; P = 0.03; I² = 99.5%), but not in subjects with Graves’ disease (GD) (WMD − 4.14 ng/dl; 95% CI, − 8.46 to 0.17; P = 0.06; I² = 97.5%). Conclusions: Our findings suggested lower vitamin D levels in patients with hypothyroidism, AITD, and HT compared to healthy subjects. However, the link between serum vitamin D and GD was only significant among subjects ≥40 years old.

Background: Polycystic ovary syndrome (PCOS) is a polygenic endocrine disorder in women of reproductive age that lead to infertility. The aim of this study was to investigate the effects of probiotic on pancreatic b-cell function and C-reactive protein (CRP) in PCOS patients. Methods: This randomized double-blind placebo-controlled clinical trial was conducted among 72 women aged 15-40 years old diagnosed with PCOS. Participants were randomly assigned to two groups receiving: (1) Probiotic supplements (n = 36), (2) placebo (n = 36) for 8-week. Fasting blood samples were taken at baseline and after 8-week of intervention. Results: Probiotic supplementation, compare with placebo, reduced fasting blood sugar (−4.15 ± 2.87 vs. 2.57 ± 5.66 mg/dL, respectively P = 0.7), serum insulin levels in crude model (−0.49 ± 0.67 vs. 0.34 ± 0.82 mIU/mL, respectively, P = 0.09), homeostasis model of assessment-insulin resistance score (−0.25 ± 0.18 vs. −0.05 ± 0.18, respectively, P = 0.14) nonsignificantly. Serum insulin levels after adjustment with covariates reduced significantly in probiotic group (P = 0.02). We did not found any significant differences in mean changes of CRP between groups (−0.25 ± 0.18 vs. −0.05 ± 0.18, respectively, P = 0.14). Conclusions: A 8-week multispecies probiotics supplementation had nonsignificantly beneficial effect on pancreatic b-cell function and CRP in PCOS patients. After adjustment for some covariates, serum insulin changes were significantly different between groups.

Background: Green tea is one of the most popular beverages in the world. It is believed to have beneficial effects in the prevention and treatment of many diseases, one of which is nonalcoholic fatty liver disease (NAFLD). The present study investigated the effects of consumption of green tea in NAFLD patients. Methods: This study was a double-blind, placebo-controlled, randomized clinical trial. Ultrasonography was used to diagnose fatty liver in patients with alanine aminotransferase (ALT) >31 mg/dl and 41 mg/dl and aspartate aminotransferase (AST) >31 mg/dl and 47 g/dl in women and men, respectively and without other hepatic diseases. A total of 80 participants (20-50 years) with NAFLD were randomly allocated into two groups to receive either green tea extract (GTE) supplement (500 mg GTE tablet per day) or placebo for 90 days. At baseline and at the end of the intervention weight, serum ALT, AST, and alkaline phosphatase (ALP) were measured in fasting state, and dietary data were collected at baseline and end of the study. Results: Green tea group showed significant reductions in ALT and AST levels after 12 weeks period (P < 0.001). The placebo group showed a reduction in ALT and AST levels at the end of the study, but it was no significant. ALP levels showed significant reductions in both groups after 12 weeks period (P < 0.001). Conclusions: According to the findings of this study, GTE supplementation decrease liver enzymes in patients with NAFLD. It can be claimed that GTE prescribed can be considered as a treatment to improve serum levels of liver enzymes in NAFLD patients.

Earlier forms of food frequency questionnaire (FFQ) used in Iran have extensive lists of foods, traditional categories and food-based design, mostly with the interviewer-administered approach. The aim of the current paper is to describe the development of a dish-based, machine-readable, semi-quantitative food frequency questionnaire (DFQ). Within the framework of the Study on the Epidemiology of Psychological, Alimentary Health and Nutrition project, we created a novel FFQ using Harvard FFQ as a model. The following steps were taken to develop the questionnaire: Construction of a list of commonly consumed Iranian foods, definition of portion sizes, design of response options for consumption frequency of each food item and finally a pilot test of the preliminary DFQ. From a comprehensive list of foods and mixed dishes, we included those that were nutrient-rich, consumed reasonably often or contributed to between-person variations. We focused on mixed dishes, rather than their ingredients, along with foods. To shorten the list, the related food items or mixed dishes were categorized together in one food group. These exclusions resulted in a list of 106 foods or dishes in the questionnaire. The portion sizes used in the FFQ were obtained from our earlier studies that used dietary recalls and food records. The frequency response options for the food list varied from 6-9 choices from “never or less than once a month” to “12 or more times per day”. The DFQ could be a reasonable dietary assessment tool for future epidemiological studies in the country. Validation studies are required to assess the validity and reliability of this newly developed questionnaire.