Tirang R. Neyestani

National Nutrition and Food Technology Research Institute, Tehran, Iran · Nutrition Research

Different phenotypes of obesity are each related with different complications and comorbidities. We hypothesized that suboptimal vitamin D status is directly associated with an unhealthy metabolic status, especially if allied with obesity. This cross-sectional study was performed in the framework of the National Food and Nutrition Surveillance. Ove...

Background Both augmented inflammatory reaction and low vitamin D status are associated with depression but the magnitude of their relationships is unclear. This study was, therefore, conducted to evaluate the effects of vitamin D supplementation on serum 25(OH)D concentration, depression severity and some pro-inflammatory biomarkers in patients wi...

Background Vitamin D deficiency, a common problem among pregnant women, is linked with maternal inflammation, oxidative stress and consequent adverse pregnancy outcomes. The aim of this systematic review was to evaluate the effect of vitamin D supplementation on oxidative stress and inflammatory biomarkers in pregnant women according to the PRISMA...

Background The pandemic of the newly emerged coronavirus infection and its related disease, Covid-19, has influenced various aspects of human life including dietary habits. This study aimed to examine changes in dairy products consumption during Covid-19 lockdown period in a huge sample of Iranian households. Methods A cross-sectional descriptive-...

Background Nutritional inadequacy, especially micronutrients, is still a serious concern among children in developing countries. Dietary diversity score (DDS) has been recommended as a proxy for nutritional adequacy. The present study aims to develop a questionnaire to assess the dietary diversity among 24–59 months children in Iran; also, the vali...

Inflammation is a natural immune response to the foreign invaders to the body. However, inflammatory reaction needs to be precisely orchestrated from initiation to termination to keep the tissues and organs of the body safe. Consequently, any defect in mounting inflammatory response or in regulating its termination could be in opposition with the s...

Background The COVID-19 epidemic has affected diverse issues of life including economy, health and nutrition. This nationwide study was conducted to evaluate the effects of the epidemic lockdown-induced socio-economic changes on animal source proteins and cereals intakes of Iran population for the first time. Methods This was a cross-sectional des...

Background and Objectives: Overweight/obesity can be consequences or causative factors of depression. Vitamin D has been suggested as a contributing factor in depression and excessive body weight; however, the existing evidence is still unclear. The objective of this study was to assess statuses of overweight and obesity in patients with depression...

Introduction: Food waste reflects inadequate food intake and is of economic and environmental importance. Therefore, understanding the underlying factors is a must to combat food waste. Methods: A qualitative study was conducted using semi-structured interviews with managers, nurses, nutritionists, food providers, kitchen staff, and inpatients of...

Background and objective: Sunlight exposure, the main source of endogenous vitamin D synthesis, may increase the risk of non-melanoma skin cancers (NMSC) development. Vitamin D receptor (VDR) polymorphisms are associated with various malignancies. This study aimed to examine the associations between vitamin D status and VDR FokI polymorphisms in I...

Aim The aim of this meta-review was to establish the effects of green tea (GT) intake on some cardiometabolic risk factors including anthropometric measures, blood pressure as well as blood glucose and lipids using evidence from previous systematic reviews and meta-analyses. Data synthesis Articles were identified via searches in PubMed, Embase, a...

Background: This study was undertaken to analyze and compare Eastern Mediterranean (EM) countries in achievement of WHO nutrition global targets for children growth indicators by 2025. Methods: A total of 108 national surveys from 20 countries in EM region were analyzed to estimate the prevalence of stunting and wasting and 93 surveys to estimate t...

Background: It is documented that vitamin D may have a role in erythropoiesis as its deficiency is accompanied by an increased risk of anemia. Aim: This study aimed to examine whether improvement of vitamin D status through daily consumption of either fortified foods or supplements could impinge on certain hematologic parameters in adults. Methods:...

The associations between components of metabolic syndrome (MetS), insulin resistance (IR), and several malignancies have been reported. However, the possible link between IR and dermal malignancies, including non-melanoma skin cancers (NMSCs), has not been investigated to date. In this study, we aimed to examine the possible association between com...

Background Fast foods, though very popular, are commonly known as unhealthy foods. However, coronavirus pandemic may have influenced on food choices of the general population. This study investigated the changes in fast food consumption during epidemic lockdown 2020. Materials and Methods This study was part of a nationwide survey having been cond...

Background Structural equation modeling (SEM) is a method used to evaluate linear causal relationships among variables. This study aimed to investigate the direct and indirect effects of serum 25(OH) D on certain cardiovascular risk factors using SEM. Methods An analytical cross-sectional study was conducted in six provinces of Iran. Subjects (n =...

Objectives: This study was conducted to respond certain important questions regarding the efficacy of vitamin D fortification and supplementation in children using a meta-analytical approach. Methods: MEDLINE, PubMed, Embase, Cochrane Library, and Google Scholar were searched, and 2341 studies were found in a preliminary search. After screening...

Background Some evidence suggests indirect ameliorating effects of vitamin D in diabetes via adiponectin and sirtuins. This study aimed to evaluate the effects of daily intake of vitamin D-fortified yogurt drink, either with or without added calcium, on serum adiponectin, sirtuins (SIRT)1 and 6. Methods Briefly, 75 adults aged 30–60 years from bot...

Improvement of vitamin D status of the general population has been a challenge for policymakers. We conducted a meta-analysis to evaluate whether vitamin D-fortified products can be a suitable solution for tackling vitamin D deficiency (VDD). Our secondary objective was to determine the effect of some variables including age, latitude and body mass...

Hospitalization may affect patients' nutritional status due to the altered food intake. In addition to their health consequences, plate food waste includes several economic and environmental costs for the governments and societies. Therefore, the aim of the present investigation is primarily to assess the nutritional status of the patients hospital...

We investigated the effect of daily intake of yogurt drink fortified with either vitamin D alone or with added calcium on resting metabolic rate (RMR), thyroid hormones and homeostatic model assessment for insulin resistance in subjects with type 2 diabetes (T2D). A total of 75 adult subjects with T2D were randomly assigned to 1 of the 3 groups to...

There is some evidence for ameliorating effect of vitamin D on glycemic and lipidemic status which are likely to be mediated through other molecules including adiponectin. However, the overall results have been controversial. This study was conducted to evaluate the effect of vitamin D supplementation on serum adiponectin concentration. MEDLINE, Pu...

Background and Objectives: The COVID-19 pandemic and consequent lockdown has multifaceted effects on people's life including fall in economy which may affect food choices. This study was designed to evaluate changes in dietary intakes of the Iranian households during COVID-19 lockdown and also to predict the consequent health impacts. Materials and...

Background Food and Nutrition Surveillance (FNS) is an essential and practical tool for providing timely information at specified times for policy making. This study aimed to explore policymakers' expectations and perception on establishment of the FNS in Iran before its establishment. Materials and methods Data in this qualitative study were gath...

Objective: This study aimed to assess the validity and reliability of a dish-based, semi-quantitative food frequency questionnaire (DFFQ) for epidemiological studies in Iran. The DFFQ included 142 items (84 foods and 58 mixed dishes) which was filled in by 230 adults (110 men). All participants completed two separate DFFQs with a 6 months interval...

Background Vitamin D deficiency during pregnancy is common and is likely to be associated with metabolic complications in the mother. The aim of this study was to assess the efficacy of two doses of vitamin D supplementation during pregnancy on maternal and cord blood vitamin D status and metabolic and oxidative stress biomarkers. Methods The elig...

Context The common approaches of home fortification (HF) for prevention and/or treatment of micronutrient deficiencies are micronutrient powders (MNPs), foodlets, and lipid-based nutrient supplements (LNSs). There are mixed results for the impact of HF on growth and nutritional status of young children. Objective This systematic review was prepare...

Background: Food frequency questionnaires (FFQs) are widely used in large studies worldwide. They usually seek to rank people according to their usual food intake rather than a specific period of time. In the present study, we aimed to develop a dish-based, semi-quantitative FFQ to seek habitual diet of general population aged 9 to 65 years in Tehr...

Purpose High prevalence of vitamin D deficiency (VDD) justifies a cost-effective and sustainable strategy to combat VDD in the community. This study was undertaken for the first time to evaluate the efficacy of daily consumption of vitamin D fortified sunflower oil with a meal. Methods This single-blind trial was conducted in two separate institut...

Background There is evidence suggesting an effect of vitamin D on glycemic status through mediators including adiponectin and sirtuins. Objective To evaluate the effects of daily intake of vitamin D-fortified yogurt drink, either with or without added calcium, on serum adiponectin, sirtuins (SIRT)1 and 6. Design Briefly, 75 adults aged 30-60 yrs fr...

Background and Objectives: This study was carried out to assess food habits and their associations with weight status and metabolic risk factors in adults in Tehran, Capital of Iran. Materials and Methods: A cross-sectional survey was conducted in a sample of adults (n=227) over 18 years old residing in Tehran. Demographic, anthropometric and food...

Background: Hospitalization may seriously affect patients’ nutritional status and may occasionally be accompanied by malnutrition development or aggravation. Food intake is often altered during hospitalization, which is tightly connected to malnutrition. On the other hand, a huge amount of plate food wasted by patients, in addition to its health co...

Some studies have reported inaccuracy of predicting basal metabolic rate (BMR) by using common equations for Asian people. Thus, this study was undertaken to develop new predictive equations for the Iranian community and also to compare their accuracy with the commonly used formulas. Anthropometric measures and thyroid function were evaluated for 2...

Background: The association of ADV-36 infection and obesity has been reported in children. The objective of this study was to examine the hypothesis that the association between ADV-36 infection and adiposity may be mediated by sub-optimal vitamin D status of the host. Methods: Ninety one apparently healthy children in different weight categorie...

An amendment to this paper has been published and can be accessed via the original article.

Background : Low vitamin D levels are associated with a dysregulated hypothalamic-pituitary-adrenal (HPA) axis and depression but a causal relationship has not been established. This study aimed to evaluate the effects of vitamin D supplementation on depression severity, serum 25(OH)D, and some neurotransmitters in patients with mild to moderate de...

Background: Despite a remarkable reduction in the occurrence of many micronutrient deficiencies in most countries, vitamin D deficiency has remained a global problem. Age-adjusted disability-adjusted life years lost due to cardiovascular disease in the Eastern Mediterranean Region, including in the Islamic Republic of Iran, are higher than the glo...

Background: Sunlight exposure, the main source of endogenous vitamin D synthesis, may increase the risk of non-melanoma skin cancer (NMSC) development. Vitamin D receptor (VDR) polymorphisms are associated with 25(OH)D levels, cancer development and insulin resistance. This study was aimed to examine the associations among vitamin D status, VDR Fok...

Hypovitaminosis D during pregnancy is suggested to have a link with complications in both mother and infant. We aimed to evaluate the efficacy of two doses of vitamin D3 supplementation during pregnancy on maternal and cord blood vitamin D status, inflammatory biomarkers and maternal and neonatal outcomes. A total of 84 pregnant women (gestational...

Background Sunlight exposure, the main source of endogenous vitamin D synthesis, may increase the risk of non-melanoma skin cancer (NMSC) development. Vitamin D receptor (VDR) polymorphisms are associated with 25(OH)D levels, cancer development and insulin resistance. Objective This study aimed to examine the associations among vitamin D status, VD...

There is a higher demand for calorie-reduced foods. In the dairy industry, fat is separated to produce low-calorie products and fat-soluble vitamins such as A and D are also removed along with them. There are different factors leading to a significant decrease in people's sun exposure, which has a substantial role in isomerisation of 7-dehydrochole...

Objective To investigate seasonal variations of vitamin D status at different latitudes and if these changes are accompanied by corresponding variations in certain health parameters in children living in a broad latitudinal range in Iran. Design Longitudinal study. Subjects In total, 530 apparently healthy children aged 5–18 years were randomly s...

Upon being born, a human must breathe and eat to survive and, as it is with other mammals, milk is the first food that the baby encounters. Nature has equipped a mother's body with such intricate machinery to produce milk with an ever-changing composition according to the infant's needs. During and after weaning, the reliance on milk as a sole sour...

Background: In several disease conditions, patients must inevitably be nourished by enteral feeding (EF). Though in many countries, commercial formulas are routinely used for EF, in Iran still home-made formulas are commonly employed as commercial formulas are not covered by insurance. This may pose patients to malnutrition and bring about further...

This study aimed to develop a new prebiotic dairy dessert by adding different concentration of cereal flours (10 – 16% w/w), inulin (6 and 8% w/w) and sugar (2 and 4% w/w) into dairy dessert formulation. A mixture design approach was used to create nine formulation of dessert samples. Desserts were evaluated by consumers who were asked to answer a...

Objective to investigate the association of 25(OH)D concentrations with the risk of anemia in a large sample of children considering the effects of gender, body mass index (BMI), serum intact parathyroid hormone (iPTH) concentrations and iron status. Subjects In a cross-sectional study, we enrolled 937 children (493 boys and 444 girls) aged 9-12 y...

Purpose: This study aimed to evaluate the effect of daily consumption of vitamin D-fortified yogurt drink (doogh) in comparison with plain doogh on appetite-regulating hormones including leptin and ghrelin in type 2 diabetes (T2D) patients. Methods: In a single blind randomized clinical trial, subjects with T2D were randomly allocated to one of...

Objective: This study aimed firstly to assess zinc and iron status of 9-12-year-old children of Tehran and secondly to determine a cut-off for circulating biomarkers of iron status to identify children at increased risk of zinc deficiency. Research methods & procedures: In a cross-sectional study, demographic and anthropometric data from 505 boy...

The results of the present meta-analysis provide evidence that a healthy/prudent pattern decreases CRP level, while adherence to unhealthy/Western pattern leads to a higher level of CRP in adults.

Background: This study aimed to evaluate the vitamin D status in an adult population across latitudinal gradient and to investigate its possible associations with certain cardiometabolic risk factors. Methods: A total of 1406 healthy subjects aged 19-60 years were randomly selected from six regions of Iran across latitudinal gradient from 29° N...

Background: Remarkable disagreement among different systems of 25-hydroxy vitamin D 25(OH)D assay makes decision making for both clinical and community interventions very difficult. This study aimed to harmonize the results obtained from different 25(OH)D assay systems. Methods: A total of 275 serum samples were analyzed for 25(OH)D using DIAsou...

Background: Bread, as the staple food of Iranians, with average per capita consumption of 300 g d-1 , could potentially be a good vehicle for many fortificants, including iron. In this study, iron bioavailability from flat breads (three fortified and one whole wheat unfortified) was investigated using in vitro simulation of gastrointestinal digest...

We aimed to investigate the potential association between vitamin D and serum leptin levels by pooling together the results from observational studies and clinical trials. A systematic literature search of PubMed, Scopus, and Google Scholar was conducted up to March 2015. The analysis of observational studies was done on six papers that reported 9...

Background Recent data indicate a role for vitamin D in many health aspects including anthropometric measures and blood lipid profiles. Dermal vitamin D synthesis may be influenced by latitude. However, the contribution of latitude in vitamin D status and its association with anthropometric and blood lipid measures in Iranian children have not been...

Background and Objectives: In the original in vitro method for evaluation of iron bioavailability using caco-2 cell model, ferritin formation by cells is considered as a functional indicator of both absorption and utilization of iron. However, as iron is measured in the tested material and then ferritin concentration is measured in caco-2 cell lysa...

Background and Objectives: Globally, the prevalence of overweight/obesity is increasing at an alarming rate. According to the World Health Organization (WHO), about 1.9 billion adults worldwide are overweight, and of these, over 600 million are obese. The purpose of this study was to determine the prevalence of overweight and obesity in West Azerba...

Context: Bread can potentially be a suitable vehicle for fortification with vitamin D. Objective: This study was undertaken to evaluate (1) bioavailability of vitamin D from the fortified Iranian bread, and (2) the possible effects of daily consumption of the fortified bread on certain health aspects. Design, setting, and participants: This wa...

Objectives: This study was performed to examine the association between household food insecurity, self-efficacy and infant feeding styles in mothers with children under 2 years old in Varamin, Iran. Methods: In this cross-sectional study, 423 mothers aged 17-40 years from different areas of Varamin were selected by a multistage sampling methods...

In this chapter, the biology of vitamin D, including its calcemic and especially noncalcemic functions, is reviewed, with a special focus on vitamin D effects on immune function. The newest findings derived from studies on association of vitamin D with MS are also critically discussed. Finally, some issues for future investigation are presented in...

Introduction: There is sparse evidence of the effect of vitamin D on bone biomarkers in diabetic patients, and therefore, in a randomized clinical trial, we evaluated the effects of the daily intake of vitamin D, either with or without extra calcium, on selected bone biomarkers. Materials and Methods: Ninety women and men aged 30 - 50 years old wit...

Oxidative stress (OS) refers to an imbalance between potentially harmful free radicals and the body's mechanisms to efficiently detoxify them in favor of the free radicals. Consequently, excess free radicals can attack to and damage a wide range of biomolecules including proteins, lipids and nucleic acids. Antioxidant mechanisms of the body are und...

Background: Health consequences of food insecurity among infants and toddlers have not been fully examined. The purpose of this study was to assess the relationship between household food insecurity, mother's infant feeding practices and iron status of 6-24 months children. Methods: In this cross-sectional study, 423 mother-child pairs were randoml...

The most reliable indicator of Vitamin D status is circulating concentration of 25-hydroxycalciferol (25(OH) D) routinely determined by enzyme-immunoassays (EIA) methods. This study was performed to compare commonly used competitive protein-binding assays (CPBA)-based EIA with the gold standard, high-pressure liquid chromatography (HPLC). Concentra...

Background: Nutrition status is an important constituent of health in an elderly and evaluation of these groups are necessary for development of treatment protocols. The study aimed to estimate the prevalence of malnutrition with mini nutritional assessment (MNA) tool in the elderly living in nursing homes. In addition, the association of MNA resul...

Objective: This study aimed to investigate the associations between metabolic syndrome and type 2 diabetes and the presence of single nucleotide polymorphism of the vitamin D receptor gene in Iranian subjects with type 2 diabetes. Subjects and methods: Overall, 730 Iranian subjects (372 patients and 358 controls) were enrolled in this case-contr...

Emerging data suggest an association between low serum concentrations of 25(OH)D and central obesity. This study aimed to investigate the effects of daily intake of vitamin D-fortified yogurt drink (doogh) on central obesity indicators in subjects with type 2 diabetes (T2D) and the possible modulation of this effect by vitamin D receptor (VDR)-Cdx-...