Showing 21 results for Vitamin D
Bahareh Nikooyeh, Tirang.r Neyestani, Hamid Alavi-Majd, Ali Kalayi, Nastaran Shariatzadeh, Malihe Zahedirad, Soudabeh Heravi, Nima Tayebinejad, Shabnam Salekzamani, Mohammad Samadi,
Volume 1, Issue 1 (9-2014)
Abstract
Background and Objectives: There is convincing evidence that subjects concomitantly affected by type 2 diabetes (T2D) and metabolic syndrome (MeS) are at greater risk for cardiovascular disease (CVD). Many metabolic derangements in T2D might be attributed to poor vitamin D status. The purpose of this study was to investigate the associations among vitamin D status, MeS and glycemic status in subjects with T2D.
Materials and Methods: A total of 101 known cases of T2D (39 males, 62 females) were enrolled in a cross-sectional study by convenient sampling. Serum 25(OH)D3, glycemic markers and lipid profile were assessed.
Results: Mean concentration of serum 25(OH)D3 was 42.2±33.8 nmol/L. Prevalence of undesirable vitamin D status (25(OH)D < 50nmol/L) was significantly higher among the subjects with MeS as compared to those without MeS (p=0.020). The subjects with sufficient vitamin D status had 50% lower risk for MeS compared to those who had vitamin D deficiency, and this association remained significant even after additional adjustment for body mass index (BMI), percent of fat mass or waist circumference.
Conclusions: Our data showed that firstly higher vitamin D status is inversely associated with fasting glycemia, and secondly serum 25(OH)D3 predicts MeS risk in the subjects with T2D. Demonstrating the association of hypovitaminosis D with disorders of glucose metabolism and higher risk for development of further complications, notably CVD, may lead to a new target for preventive efforts at the population level.
Keywords: Vitamin D, Type 2 diabetes, Metabolic syndrome, Cardiovascular disease
Maliheh Zahedi-Rad, Bahareh Nikooyeh, Ali Kalayi, Nastaran Shariatzadeh, Tirang R. Neyestani,
Volume 2, Issue 2 (4-2015)
Abstract
Background and Objectives: Day-shift taxi drivers have a long duration of direct sun exposure. However, the efficiency of this occupational exposure in vitamin D synthesis has not been addressed yet. The aim of this study was to assess the vitamin D status of taxi drivers in Tehran, and examine vitamin D status association with some anthropometric and circulating biomarkers.
Materials and Methods: In a case control study, 53 taxi drivers and 80 apparently healthy subjects from other occupations were enrolled. Questionnaires for demographic data, supplement use, and duration of sun exposure were completed. Weight, height and waist circumference were measured. Blood samples were taken from all participants for complete blood cell count, fasting blood glucose (FBG), lipid profile, and 25-hydroxycholecalciferol (25 (OH)D) measurements.
Results: Taxi drivers, as compared to the controls, had significantly higher body mass index (BMI), waist circumference (WC), serum triglycerides (TG), and 25(OH)D concentrations. Moreover, 56.6% of the drivers had more than 2 hours of sun exposure during a day.
Conclusions: Despite having higher circulating concentrations of 25(OH)D, the taxi drivers had higher cardiometabolic risk factors. These findings indicate a need for nutritional education for taxi drivers.
Keywords: Vitamin D, Driving, Sun exposure
Maliheh Zahedirad, Bahareh Nikooyeh, Tirang R. Neyestani,
Volume 2, Issue 3 (6-2015)
Abstract
Background and Objectives: Vitamin D deficiency/insufficiency is a global health problem. The importance of this problem is doubled in growing children because of their increased need for skeletal growth. This investigation was performed firstly to assess vitamin D status, and secondly to examine its possible relationship with sex, residing area and duration of sun exposure in 9-12 years old children of Tehran.
Materials and Methods: We studied 257 randomly selected children out of 1111 children of a huge study, titled “Vitamin D and Calcium Deficiency Prevalence of Tehran’s Elementary School Children (VDPT)”, performed in fall and winter 2008 in Tehran. The children were without the history of diabetes, allergy or autoimmune disease, and any calcium, vitamin D and fish oil supplement use during the last three months. Venous blood samples were taken, and the sera were analyzed by high performance liquid chromatography (HPLC) for measuring 25-hydroxycalciferol (25(OH)D).
Results: The participating children comprised of 53.7% girls and 46.3% boys from different economical areas of Tehran (40.5% poor, 26% middle and 33.5% rich). Their mean age was 10.1±0.7 years, mean duration of sun exposure was 41.2±34.6 min/day, and mean serum 25(OH)D concentration was 21.9±15.6 nmol/L. Duration of sun exposure was not significantly different either between boys and girls (p=0.220), among different residing areas (p= 0.057), or between the girls and boys of different areas. The occurrence of vitamin D deficiency was 72.4% (n=186). Vitamin D status was significantly different between boys and girls (p= 0.01) and among the areas (P= 0.004). There was no significant relation between poor vitamin D status and duration of sun exposure (p=0.411).
Conclusions: The findings showed a noticeable occurrence of vitamin D deficiency/insufficiency among 9-12 years old children in Tehran. The data warrants urgent interventions.
Keywords: Vitamin D, 25-hydroxycalciferol, School children
Behnaz Abiri, Mohammad Reza Vafa, Mohsen Dehghani, Nazanin Moslehi, Javad Sarrafzadeh,
Volume 3, Issue 3 (7-2016)
Abstract
Background and Objectives: Sarcopenia is explained as the loss of muscle strength and muscle mass with aging‚ and is one of the major risk factors for metabolic diseases. Cross-sectional studies demonstrate that vitamin D is associated with sarcopenia in both men and women. The aim of this study was to investigate the effect of vitamin D supplement consumption on muscle strength, muscle function and body composition in middle-aged women.
Materials and Methods: In this randomized double-blind placebo-controlled trial, 71 women aged 40-55 years old, with the serum 25(OH)-D <25 ng/ml, were divided in two groups randomly, and received a 1000 IU vitamin D tablet (n=37) or a placebo (n=34), daily for 12 weeks. At the beginning and at the end of the study, dietary intake, anthropometric indices, muscle strength and function, serum 25(OH)-D, physical activity level and sun exposure were assessed. Statistical analysis was performed with SPSS version 20.
Results: A significant difference in serum 25(OH)-D was found between the intervention and placebo groups at the end of the study (P<0.001). In the vitamin D group, handgrip strength was improved, while hand grip strength (P=0.233) and knee extension strength (P=0.337) between the two groups did not differ significantly after 12 weeks. The mean of timed get up and go test, decreased significantly in the vitamin D group compared to the controls (P<0.001). Within the intervention group, body fat content decreased significantly after 12 weeks (P<0.001), but did not result a significant difference between the two groups (P=0.051).
Conclusions: It seems in this vitamin D-deficient middle-aged women group, 1000 IU vitamin D consumption daily for 12 weeks resulted in improvement of muscle function and body composition, but had no significant effect on muscle strength.
Keywords: Vitamin D, Muscle strength, Muscle function, Middle-aged women
Bahareh Nikooyeh, Tirang R Neyestani,
Volume 4, Issue 2 (4-2017)
Abstract
since early works on isolation and characterization of vitamin D by Elmer Verner McCollum and Edward Mellanby in 1900s, this molecule still seems mysterious (1-2). After several decades since discovery of the miraculous effect of cod liver oil in treatment of nutritional rickets, escalating number of reports provide a huge body of evidence for various effects of vitamin D on human body (3). The spectrum of vitamin D health effects is quite wide, from bone and muscles (so-called calcemic effects) to a variety of non-calcemic effects including cardiovascular, insulin function, adipogenesis, obesity, immunity and mental status. Consequently, having an optimal vitamin D status has attracted a huge attention (4-8).
Despite the fact that the body is equipped with the vitamin D photosynthetic machinery, undesirable vitamin D status is a global health problem due to many geographical, environmental as well as socio-cultural reasons (9-10). However, unlike most other nutrients, there is no consensus on definition of “desirable vitamin D status”. It is generally accepted that circulating 25-hydroxycalciferol (25(OH)D) concentration can well reflect the body's vitamin D status (11). However, there is no agreement on desirable serum 25(OH)D level (12). While some scientific bodies recommend concentrations above 50 nmol/L (13), some vitamin D experts criticize this recommendation and suggest as high concentrations as 75 and 100 nmol/L and even above (10). As a result, different research groups usually based on their experience, recommendation of the manufacturers of the commercial assay kits and
occasionally their tastes use various cutoff points to define vitamin D status of their study population. Needless to say that the occurrence rates reported by these studies may hardly be comparable. The problem of definition of vitamin D status becomes even more complicated when considering the effect of assay system on 25(OH)D test results (14).
Table 1 shows some of the cross-sectional researches preformed over a decade ago. The cutoffs used, range from 23 nmol/L (15) to as high as 87.5 nmol/L (16). Interestingly the prevalence of undesirable vitamin D status in 20-64 yr males based on 23 nmol/Lwas reported 81.3% (15) while in another study on mothers of newborns, the prevalence rate was as low as 5.7%, based on 25(OH)D<50 nmol/L (17). Part of these discrepancies might be due to the methods used in various studies. Disagreement of 25(OH)D assay results obtained from different assay systems has been already reported (14, 18-22). This could potentially disturb decision making at the clinical settings (23).
At the national level, two nationwide surveys on vitamin D are noticeable. In 2001, the first National Integrated Micronutrient Survey (NIMS I), reported the prevalence rates of undesirable vitamin D status among 15-23 month children and pregnant women as 3.7% and 0.9%, respectively (24). However, after a decade the prevalence rates in these age groups tremendously increased to 23.7% and 86%, respectively, as reported by NIMS II (25). These unexpectedly worrying numbers vigorously stimulated stake-holders at Deputy of Health of the
Iran Ministry of Health (MOH) to hold several sessions in order to take an urgent action. These sessions led to recommendations and implementations of supplementation for different population subgroups across the country.
Table 1. Occurrence rates of undesirable vitamin D status using different assay methods in different Iranian subpopulations
|
Author, year
|
Population
|
Method
|
Cutoff
|
Prevalence of undesirable vitamin D status
|
|
Moussavi M, [et al], 2005 (43)
|
153 boys and 165 girls, aged 14-18 yr
|
RIA
|
< 50 nmol/L
|
all subjects: 46.2% (72.1% in females and 18.3% in males)
|
|
Hashemipour S, [et al], 2004 (15)
|
1210 subjects 20-64 yr
|
RIA
|
Normal range: 23 to 113 nmol/L
|
81.3%
|
|
Salek M, [et al], 2008 (17)
|
88 newborns and their mothers
|
RIA
|
Mothers: < 50 nmol/L
Newborns: < 31.2 nmol/L
|
Mothers: 5.7%
Newborn: 4.5%
|
|
Kazemi A, [et al], 2009 (44)
|
67 full-term pregnant mothers
|
-
|
< 25 nmol/L
|
86% of the women and 75% of the newborns during winter and 46% of the mothers and 35% of the newborns during summer
|
|
Rahnavard Z, [et al], 2010 (16)
|
2396 healthy men
|
EIA
|
< 87.5 nmo/L
|
68.8%
|
|
Hovsepian S, [et al], 2011 (45)
|
1,111 healthy people-243 men and 868 women, 20-80 yr
|
RIA
|
< 75 nmol/L
|
70.4%
|
|
Kashi Z, [et al], 2011 (46)
|
351 subjects (66.4% women, 33.6% men) aged 11 to 69
|
EIA
|
< 75 nmol/L
|
87.5% in winter and 78.6% in summer
|
|
Kaykhaei MA, [et al], 2011 (47)
|
993 apparently healthy subjects
|
ECL
|
< 75 nmol/L
|
94.7%
|
|
Khalesi N, [et al], 2012 (48)
|
100 neonates and their mothers
|
Not reported
|
Not reported
|
85% of neonates and 74% of mothers
|
|
Neyestani TR, [et al], 2012 (27)
|
1111 children aged 9-12 yr
|
EIA
|
< 50 nmol/L
|
91.7 %
|
|
Talaei A, [et al], 2012 (49)
|
420 students 10-16 yr
|
RIA
|
< 50 nmol/L
|
84%
|
|
Alipour S, [et al, 2014 (50)
|
538 women aged 20-80 years
|
ECL
|
<35 nmol/L
|
69%
|
|
Faghih S, [et al], 2014 (51)
|
254 university students (19-32 yr)
|
RIA
|
< 75 nmol/l
|
95.2% of males
97.5% of females
|
|
Saki F, [et al], 2015 (29)
|
children (n=477) aged 9-18 years
|
HPLC
|
< 75 nmol/L
|
96%
|
|
Abbasian M, [et al], 2016 (52)
|
284 pregnant women and their newborn
|
EIA
|
< 75 nmol/L
|
Mothers: 61.3%
Neonates: 51.4%
|
|
Larijani B, [et al], 2016 (30)
|
444 middle and high school students
|
EIA
|
< 75 nmol/L
|
77.6%
|
Abbreviations: ECL: electrochemiluminescence; EIA: enzyme immunoassay; HPLC: high-performance liquid chromatography; RIA: radioimmunoassay.
Notwithstanding, some points have seemingly been overlooked in interpretation of NIMS II findings. Firstly, the 25(OH) D assay method used in NIMS I was radioimmunoassay (RIA) whereas in NIMS II was electrochemiluminescence binding immunoassay (ECLIA) using Elecsys system. Disagreement among different 25(OH) D systems has been demonstrated in several studies which was more prominent for RIA than the other systems (19-20, 22). More importantly, the cutoffs used to define vitamin D deficiency in NIMS I was 25(OH)D < 12 and <25 nmol/L while in NIMS II was <25 and <50 nmol/L for vitamin D deficiency and insufficiency, respectively (24-25). Obviously, this rise in cutoff points could cause a great increment in the prevalence rates.
The National Food and Nutrition Surveillance (FNS) revealed 93% of the Iranian children have suboptimal circulating 25(OH) D (< 50 nmol/L) during cold seasons (26). This occurrence rate is quite comparable with our earlier reports from Tehran children (27). Similar occurrence rates were observed in adults across latitudinal gradient (28). In these studies similar cutoff points and assay methods were employed. Other studies that used similar cutoffs but different assay systems reported different occurrence rates in almost similar age groups (29-30).
Though lots of reports suggest a pandemic of vitamin D deficiency (31-36), some researchers believe that this is a misconception (37). They believe that the Institute of Medicine (IOM) recommendation for desirable circulating 25(OH) D concentration is based on recommended daily intake (RDA) for vitamin D. However, RDA considers the population at the highest end of distribution whereas estimated average requirement (EAR) gives a more realistic picture of the population’s requirement. It is noteworthy that neither RDA nor EAR considers solar exposure. According to these researchers, based on EAR half of the population would need to have circulating 25(OH)D ≤ 40 nmol/L (16 ng/mL) (37). A major critique of this notion is that only calcemic effects of vitamin D were considered. Besides, it has been estimated that daily intake of 440 IU vitamin D (=11 μg) would result in 19.4 (CI: 13.9-24.9) nmol/L increment in serum 25(OH)D (38). Therefore, daily intake of vitamin D as much as RDA (600 IU) and EAR (400 IU) would result in an average increase of 26.4 and 17.6 nmol/L in circulating calcidiol. That means neither RDA nor EAR would be efficient in raising serum calcidiol concentrations to as high as 50 and 40 nmol/Lrespectively. at least in those people who do not have enough solar exposure for any reason.
The situation therefore seems absolutely confounding. The key question is raised as “what is the definition of vitamin D deficiency?” In other words, which criteria are mostly suitable for the Iranian population? Answer to this question is undisputedly important. One of the viable and sustainable strategies to tackle micronutrient deficiencies (including vitamin D) is fortification of staple foods (39). Without a concrete criterion, it would be hard, if not impossible, for stake-holders to decide how to implement and how to evaluate the effectiveness of the fortification program.
The other important issue is the variability of calcidiol assay results from different assay systems. To overcome this problem, employment of assay-specific cutoff points (40) as well as harmonization and standardization of the assay results have been proposed (41-42). Based on our experience, we believe that circulating 25(OH)D concentrations of 50 nmol/L (20 ng/mL) and above based on HPLC assay system could be considered adequate. This cutoff point could vary according to the assay system (42). Nevertheless, a national consensus is urgently needed on definition of adequate vitamin D status. Until that day, that we do hope it comes very soon, the establishment of a sustainable effective strategy against vitamin D deficiency is absolutely unrealistic.
Omid Nikpayam, Golbon Sohrab,
Volume 4, Issue 4 (9-2017)
Abstract
Background and Objectives: The polycystic ovary syndrome (PCOS) is one of the most common diseases diagnosed in women of childbearing age which is associated with increased risk of metabolic complications, including cardiovascular disease. Increasing C-reactive protein (CRP) as an inflammatory factor is common in these patients. In addition, vitamin D deficiency is quite common among females with PCOS. The aim of this study is to determine the relationship of CRP levels with vitamin D and metabolic factors in Non-obese Patients with PCOS.
Materials and Methods: This experimental study was done on 100 non-obese 20-40 years old females (BMI<30) who were diagnosed with PCOS. Based on CRP levels, the females are categorized in two groups (normal CRP<0.8 mg/dl). The serum levels of HOMA-IRC, FBS, HDL-C, LDL-CHL, Vitamin D and CRP of participants in the study were measured. Then, collected data was analyzed through the SPSS Software (version. 23). In all analysis, the p-value is presumed to be less than 0.05.
Results: The mean age of patients was 27.11±6.25. Patients in high CRP group, had significantly lower levels of HDL-C and higher Triglyceride (TG) compared to controls. In addition, the increase in CRP was associated with vitamin D deficiency. This was while no significant difference between the two groups of patients were observed in terms of insulin resistance.
Conclusions: The findings of present study suggest that higher CRP levels are positively correlated with vitamin D and HDL-C deficiency as well as an increased TG levels in non-obese females with PCOS. These findings have significant implications for the understanding of how vitamin D deficiency can contribute to inflammatory and metabolic responses in patients with PCOS. A future study could assess the long-term implications of vitamin D supplementation on inflammation and metabolic outcome of patients with PCOS.
Mehrnaz Tabibian, Malihe Sadeghi, Javad Mohtadinia, Mina Babashahi, Maryam Mirlohi,
Volume 5, Issue 1 (1-2018)
Abstract
Background and Objectives: : Vitamin D3 measurement in food and fortified food matrixes is usually interrupted by several variables. This study aimed to elaborate a specific vitamin D3 quantification method for fortified Taftoon bread considering different influential variables in each step of measurement.
Materials and Methods: Dough was fortified with (4μg/100g) and the standard protocol No.13579 was followed with some modification in the extraction and determination steps.
Results: Addition of ethanol before adding potassium hydroxide and heating up the samples in tight containers in saponification step ceased clumping the extracts and helps it’s homogeneity. In extraction, distilled water addition following extraction with diethyl ether and Petroleum ether, adding ethanol at each step of washing and using SPE column result in an appropriate experimental extract. In the chromatography step, mobile phase substitution from methanol to 5:95 water, methanol mixture provided the method with more differentiation power. Using the above condition, commercial vitamin D3 was recovered from fortified Taftoon dough with 82-100% recovery and recovery of spiked vitamin D2 from dough and bread were ranged as 94 and 86.5%, respectively, Limit Of Detection(LOD) and Limit Of Quantification(LOQ) of the method were 0.04 and 0.1mg L-1 respectively, which equaled 5μg/Kg and 10μg/Kg. True retention for the added commercial vitamin D3 in Taftoon bread was obtained as 83.4% which increased to 92% after six months storage in freezer.
Conclusions: Results of this study can be used to specify a protocol for vitamin D3 measurement in fortified bread samples. Modified experiment which is projected in this study would specify the general protocol of vitamin D3 measurement that was previously proposed in the national standard of Iran for developing a new and practical national standard document.
Bahareh Nikooyeh, Majid Hajifaraji, Amir-Hossein Yarparvar, Zahra Abdollahi, Mahnoosh Sahebdel, Amaneh Mosayebi Dehkordi, Dena Norouzi, Seyed Masoumeh Taghizadeh, Ali Kalayi, Nastaran Shariatzadeh, Maliheh Zahedirad, Tirang Neyestani,
Volume 5, Issue 1 (1-2018)
Abstract
Background and Objectives: Reports indicate that hypovitaminosis D is extremely common worldwide and is re-emerging as a major health problem globally. In the present study, the main objectives were: 1) to examine whether healthy men and women living in Ahvaz have adequate vitamin D status; 2) to assess association between vitamin D status and some cardiometabolic risk factors.
Materials and Methods: This was a cross-sectional study which was part of the National Food and Nutrition Surveillance (NFNS). A total of 235 apparently healthy women and men aged 20-60 met the inclusion criteria from the city of Ahvaz (latitude 31.3oN, 48.6oE). Anthropometric measurements including weight and height were taken. Serum 25-hydroxyvitamin D (25(OH)D) concentrations and lipid profile including triglycerides, total cholesterol, LDL-C and HDL-C were evaluated.
Results: Mean circulating 25(OH)D concentration was 25.4±12.7 nmol/L, with significant difference between men and women (p=0.015). Only 6 % of the participants had sufficient levels of vitamin D (25(OH)D ≥ 50 nmol/L). Results of logistic regression analyses after controlling for gender showed that subjects with hypovitaminosis D were almost 4.38 times more likely to be overweight/obese compared with subjects with vitamin D sufficiency (OR:4.38, p:0.011). There was no significant association between serum 25(OH)D concentration and the lipid profile components.
Conclusions: We found high prevalence of hypovitaminosis D in apparently healthy adults in Ahvaz, a sunny city of Iran. Our findings suggest that high vitamin D concentrations among the adult population are associated with a substantial decrease in body mass index. However, there was no association with the lipid profile components.
Soudabe Motamed, Bahareh Nikooyeh, Tirang R. Neyestani,
Volume 5, Issue 3 (6-2018)
Abstract
Background and Objectives: Vitamin D deficiency during pregnancy is prevalent throughout the world and has been associated with complications in mothers and infants. The aim of this study is to evaluate the efficacy of two doses of vitamin D supplementation (1000 IU/d versus 2000 IU/d) during pregnancy on maternal and cord blood vitamin D status, metabolic, inflammatory and oxidative stress biomarkers as well as maternal and neonatal outcomes (birth size and Apgar score).
Methods: A total of 84 pregnant women with the eligible criteria are randomly allocated to one of the two supplementation groups: (a) 1000 IU/d vitamin D which is routinely given to pregnant women, and (b) 2000 IU/d. Biochemical assessments of mothers are performed at the beginning and 34 weeks of gestation. They include serum concentrations of 25-hydroxycalciferol (25(OH)D), calcium, phosphate, intact parathyroid hormone (iPTH), fasting serum glucose (FSG), insulin, lipid profile including triglycerides (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL_C), as well as high sensitivity C-reactive protein (hs-CRP) and the maternal cell-culture supernatant concentrations of inflammatory cytokines IL-1β, IL-6 and TNF-α. Assessments of infants at delivery comprise cord blood serum concentrations of 25(OH)D, iPTH, hs-CRP, IL-1β, IL-6, TNF-α birth sizes and Apgar score.
Discussion: The results obtained from the clinical efficacy trials on the appropriate dose for vitamin D supplementation during pregnancy are controversial. The current study could be a step to attenuate the existent controversy on evaluating the efficacy of two doses of vitamin D supplement on a wide spectrum of both mother and newborn outcomes. Meanwhile our study could give a clue to the policy-makers at MOH by revealing the efficacy of currently prescribed 1000 IU/d vitaminD3 versus 2000 IU/d.
Zahra Saghafi, Bahareh Nikooyeh, Ali Jamali, Mercedeh Mehdizadeh, Azizollaah Zargaraan,
Volume 5, Issue 4 (10-2018)
Abstract
Background and Objectives: Previous research has established that Vitamin D3 (Cholecalciferol) deficiency is considered to be a highly prevalent nutritional problem worldwide. Data from National Food and Nutrition Surveillance Program (2015) revealed that prevalence of vitamin D3 deficiency in Iran is more than 70% of the population. Vegetable oils are considered to be potential candidates for fortification with vitamin D3. Although exposure to high temperatures has been shown to cause adverse effects in vitamin D3 content of food products, research to date has not yet determined the stability of added vitamin D3 in vegetable oils during cooking procedures.
Materials and Methods: An 80/20 % (eighty/twenty) mixture of fortified oils/water subjected to low temperature (105°C, for 0, 60, 120 and 180 minutes) and high temperature (160°C, for 0, 5, 10, 15, 20, 30, 60 minutes) under reflux condition in order to determine the destruction rate of vitamin D3. The vitamin D3 concentration was determined by HPLC method with following operating conditions: apparatus, SHIMADZU10-ATVP; column, C18 column, 5 mm, 150_4mm id; mobile phase, methanol; ambient temperature; flow rate, 1.0 ml/min
Results: This study has identified that retention rate of added vitamin D3 in corn, sunflower and canola oils during normal cooking process varies from 68.6% to 87.4%.
Conclusions: This study has shown that retention of added vitamin D3 in various vegetable oils depends on the range of natural vitamin D3 retention in cooking of foodstuffs. This result will be of interest to clinical researchers and policymakers concerned with the fortification of food products mainly vitamin D3 fortification.
Bahareh Nikooyeh, Tirang Neyestani,
Volume 5, Issue 4 (10-2018)
Abstract
There are a number of reports showing high prevalence of hypovitaminosis D across Iran. The objective of this study was to evaluate whether food fortification with vitamin D has the potential to increase serum 25(OH)D concentrations in Iranian people. MEDLINE, PubMed, EMBASE, and The Cochrane Central Register of Controlled Trials were searched for randomized controlled clinical trials involvingIranian participants to assess the effect of fortified food either with vitamin D2 or D3 (with or without calcium) versus control on serum 25(OH)D concentrations. Four studies used dairy products as a food source and bread was used in one experiment. The daily dose of vitamin D3, 1000 and 2000 IU, and the duration of administration ranged from 8 to 12 weeks. The moderate heterogeneity was detected across the included studies (P<0.00001; I2=55%).Using a random effects analysis (n=193), the efficacy effect was 34.6nmol/L (95% CI: 28.6, 40.8). The present meta-analysis showed that food fortification with vitamin D could be an effective tool to prevent and control hypovitaminosis D and Iranian population will most probably benefit from the vitamin D fortification as a national policy.
Mina Kaviani, Bahareh Nikooyeh, Hamid Zand, Parichehreh Yaghmaei, Tirang R. Neyestani,
Volume 6, Issue 4 (11-2019)
Abstract
Background and Objectives: Up to date, several pathophysiological mechanisms are suggested for evolution of depression, including inflammation, neurotransmitter and vitamin D pathways. The aim of this study is to evaluate the effects of vitamin D supplementation on serum 25-hydroxycalciferol [25(OH) D], intact parathyroid hormone (iPTH), some pro-inflammatory biomarkers and neurotransmitters supposedly involved in depression. Furthermore, effects of the vitamin D are studied on depression status in affected patients.
Materials and Methods: Patients with mild to moderate depression, aged 18–60 y, are participated in the study and randomly assigned into intervention (50,000 IU of cholecalciferol per two weeks) or control (placebo) groups. Duration of the intervention is eight weeks. Demographic and anthropometric parameters, blood pressure, biochemical values and depression status are recorded before and after intervention. Biochemical tests include serum 25(OH)D, iPTH, high-sensitivity C-reactive protein (hs-CRP), interleukin-1β (IL-1β), interleukin-6 (IL-6) and also neurotransmitters involved in depression include platelet serotonin and serum oxytocin.
Conclusions: Several parameters are linked to vitamin D and depression status. Findings of this study can help clarify roles of these parameters, which may further be used in depression preventive and therapeutic strategies.
Fateme Rezaiian, Bahareh Nikooyeh, Tirang R. Neyestani,
Volume 7, Issue 1 (1-2020)
Abstract
Background and Objectives: Evidence indicate relationships between the sunlight exposure, vitamin D status and non-melanoma skin cancer (NMSC) risk. Vitamin D receptor (VDR) polymorphisms have been linked to metabolic changes in insulin resistance and various cancers. The purpose of this study is to investigate relationships between the sunlight exposure and the NMSC risk. Furthermore, relationships between the VDR FokI polymorphism and vitamin D status and the insulin resistance in NMSC patients will be assessed.
Materials and Methods: A hospital-based case-control study is designed. Participants are randomly categorized into case and control groups. Eligible patients are adults who meet the inclusion criteria with verified diagnosis of NMSC with signed informed consents. Totally, 73 NMSC diagnosed cases and 72 healthy controls are recruited and their sunlight exposure data and genetic information are collected via interviews and high-resolution melting (HRM), respectively.
Conclusions: There are controversial reports on the relevance of sunlight exposure to non-melanoma skin cancer risk due to the dual effect of UVB radiation on promoting vitamin D3 synthesis in the skin and increasing DNA damage leading to skin cancer. Results of this study provide data on how much sunlight exposure includes beneficial health effects with no skin cancer risks. Vitamin D status may affect risks of insulin resistance-linked diseases such as cancers. Findings will contribute to the current knowledge of the roles of vitamin D, insulin resistance and FokI polymorphism in skin cancer development.
Vahid Ranaei, Zahra Pilevar, Tirang R Neyestani,
Volume 8, Issue 1 (1-2021)
Abstract
Several mitigation and suppression policies, such as social distancing, city lockdowns, remote working, testing, providing personal protective equipment and health care resource availability have been implemented by the governments in response to Covid-19 pandemic. Until now (October 23, 2020), over 1.14 million deaths in the world including 31,650 just in Iran have been officially attributed to this newly emerged viral disease (1). There is an enormous variation in the clinical symptoms of Covid-19, ranging from a mild common cold to severe symptoms such as acute respiratory distress syndrome (ARDS) and septic shock. Several factors may influence the severity of Covid-19 disease such as co-infection, co-morbidities, genetic and host factors including race, age, and obesity (2). Currently, there is no effective drug or vaccine available to treat or prevent the disease.
Mina Kaviani, Bahareh Nikooyeh, Hamid Zand, Parichehreh Yaghmaei, Tirang. R Neyestani,
Volume 8, Issue 4 (10-2021)
Abstract
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, considering possible roles of vitamin D.
Materials and Methods: A cross-sectional study was carried out on 56 18–60 year-old patients with mild to moderate depression. Demographic data were collected, serum 25(OH)D and anthropometric indices were assessed. Statuses of weight and abdominal obesity were assessed based on the body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR), respectively. Data analyses were carried out using SPSS Software v.21.
Results: The mean weight of the patients was 75.44 ± 14.52 kg. Moreover, 42.86 and 39.25% were overweight and obese indices, respectively. Most of the participants included abdominal obesity (96.43 and 60.71% based on WC and WHR, respectively). The mean of serum 25(OH)D was 80.37 ± 30.78 nmol l-1 . Results of multiple regression revealed that age was significantly linked to depression; however, this relationship was not statistically significant for anthropometric variables.
Conclusions: Overweight and obesity were prevalent in patients with mild to moderate depression. Appropriate preventive policy-making to carry out nutritional interventions with increasing physical activity (PA) seem necessary to decrease treatment costs in these patients.
Shiva Borzouei, Farid Azizi Jalilian, Fereshteh Mehri, Saeid Bashirian, Fatemeh Torkaman Asadi, Salman Khazaei,
Volume 9, Issue 2 (4-2022)
Abstract
Background and Objectives: Clinical evidence on the nutritional statuses of COVID-19 patients and their associations with COVID-19 clinical outcomes are limited. To the best of the authors’ knowledge, no studies have been carried out on COVID-19 patients of Iranian population. Therefore, the aim of this study was to assess vitamin D, vitamin B12, RBP, zinc, selenium, copper and magnesium levels in patients with COVID-19. Furthermore, associations of nutrient levels with the disease-linked death were investigated.
Materials and Methods: This cross-sectional study was carried out in hospitals affiliated to Hamadan University of Medical Sciences, Hamadan, Iran, on 98 COVID-19 positive patients, March to May 2020. Demographic and clinical data of the patients were collected from their clinical records. Blood samples of 5 ml were collected from the patients, which were used for hospital routine laboratory assays as well as measuring trace elements and vitamins. Comparison of chemical biomarkers based on the patient’s treatment outcomes was carried out using Mann-Whitney U test. For data analysis, Stata Software v.14 was used.
Results: From 98 COVID-19 positive patients, 16 (13.33%) patients died during the treatment. These patients had higher proportions of heart diseases (37.5% against 10.98%, p = 0.007). Moreover, the median of white blood cell counts was significantly higher in patients, who died during treatment (p = 0.002). For vitamin D3, vitamin B12, RBP, zinc, selenium, cupper and magnesium, 59.2, 12.24, 53.08, 30.61, 88.71, 16.33 and 26.53% of the patients had values below the reference value ranges of these elements, respectively. Comparison of chemical biomarkers based on the patient’s treatment outcomes did not show significant differences (p > 0.05).
Conclusions: Although results of this study did not show significant differences between the levels of the trace elements and vitamins with the outcomes in COVID-19 patients due to the small sample size of the present study, assessment of these relationships needs stronger evidence by designing large studies.
Neda Lotfollahi-Haghi, Saeid Ghavamzadeh, Shahsanam Gheibi, Siamak Asri-Rezaei, Zeinab Esmaeilzadeh,
Volume 9, Issue 3 (8-2022)
Abstract
Background and Objectives: Vitamin D deficiency is prevalent in patients with cystic fibrosis. However, possible effects of vitamin D deficiency on growth of children with cystic fibrosis is still unclear. The aim of this study was to assess vitamin D status and its associations with growth indices in cystic fibrosis children.
Materials and Methods: This cross-sectional descriptive study was carried out on registered cystic fibrosis patients residing in West Azerbaijan Province, Iran. Demographic, anthropometric and dietary assessments were carried out as well. The growth indicators, including weight‐for‐age, length‐for‐age, weight‐for‐length and body mass index‐for‐age Z-scores and percentiles, were assessed based on recommendations by World Health Organization and Centers for Disease Control and Prevention. Vitamin D status was assessed using serum 25-hydroxycalciferol [25(OH)D3] assay and concentrations of less than 20 and 20–30 ng/ml were considered deficiency and insufficiency, respectively.
Results: A total of 38 cystic fibrosis patients aged 91.7 m ±62.6 were enrolled in the study. Numbers of participants with no supplementation, insufficient (< 400 IU [< 1 y] and < 800 IU [> 1 y]) and sufficient supplementation were 12 (31.6%), 12 (31.6%) and 14 (36.8%), respectively. However, frequency of vitamin D insufficiency and deficiency was 30 (78.9%). Positive correlations between serum concentration of (25(OH)D3) and weight‐for‐age and body mass index for age Z-scores were reported. Based on body mass index for age percentile, healthy weight participants had higher serum concentrations of (25(OH)D3), compared to underweight patients (28.8 ±11 against 20.9 ±3.4; p < 0.05).
Conclusions: This study revealed that supplementation could improve serum concentrations of (25(OH)D3); however, rate of vitamin D insufficiency was high (64%)even in sufficiently supplemented participants. Appropriate supplementation and maintaining desired levels of 25(OH)D3 may have beneficial effects on cystic fibrosis patients’ growth.
Bahareh Nikooyeh, Tirang R. Neyestani,
Volume 10, Issue 3 (10-2023)
Abstract
Vitamin D was identified over one hundred years ago, yet vitamin D deficiency (VDD) is still the most prevalent nutritional problem all around the world. The National Food and Nutrition Surveillance together with other reports have documented alarming rates of VDD and its possible adverse consequences in both children and adults in Iran. However, the prevalence rates of VDD reported by various research groups show a wide range. In this short review, we discuss some of the main causes of these discrepancies and propose some strategies to minimize them. Finally, some key recommendations for future studies and combating VDD are presented for policymakers.
Highlights:
- Vitamin D deficiency (VDD) is a global health problem and Iran is no exception. Nevertheless, the prevalence rates of VDD reported by various research groups show a wide range.
- To have a better picture of vitamin D status in the community, standardization of definitions of vitamin D status and laboratory methods is necessary.
- One approach to minimize inter-method variations of 25(OH)D assay is harmonization.
- Using any method to assay circulating 25(OH)D, VDD prevalence rate of 50 percent and above is undoubtedly a major health problem and necessitates prompt intervention.
- Vitamin D fortification of flour is an effective strategy to improve vitamin D status of the community but must be examined in a pilot study.
Bahareh Nikooyeh, Mohammad Esmail Motlagh, Tirang Neyestani,
Volume 11, Issue 1 (3-2024)
Abstract
Background and Objectives: Vitamin D, crucial for bone health and calcium homeostasis, also impacts metabolic processes and endocrine functions. It may influence leptin, a key hormone regulating energy balance. This meta-analysis evaluates the effect of vitamin D supplementation on serum leptin concentrations, addressing inconsistencies and exploring its potential role in metabolic health.
Materials and Methods: This review examined supplementation with vitamin D, alone or with calcium, as an intervention for its effects on serum leptin concentrations. Following PRISMA guidelines, a comprehensive search of electronic databases up to March 2024 identified eligible trials. Eleven randomized clinical trials were included, assessing vitamin D supplementation versus placebo or control. The meta-analysis, registered in PROSPERO (www.crd.york.ac.uk/ PROSPERO/ CRD42020177472), used STATA for statistical analysis, with outcomes reported as mean differences (MD) and 95% confidence intervals (CIs).
Results: Initially, 503 studies were identified, with 366 excluded after screening. Ultimately, 11 studies with 819 participants were included. Trials varied in vitamin D dosage, frequency, and whether calcium was included. Pooled analysis found no significant effect of vitamin D on leptin concentrations (MD: -0.13, 95% CI -1.12 to 0.87). Subgroup analyses showed no differences based on intervention duration or calcium inclusion.
Conclusions: Our meta-analysis demonstrated that vitamin D supplementation does not significantly affect serum leptin levels, adding to the existing evidence on vitamin D metabolic roles. Further research is crucial to unravel the interaction between vitamin D and adipokines like leptin, given widespread vitamin D deficiency and its metabolic implications.
Reyhaneh Entezari, Vahid Pouresmaeil, Amir Amirabadi, Vahid Saadatian, Payam Izadpanahi,
Volume 11, Issue 4 (11-2024)
Abstract
Background and Objectives: In colorectal cancer patients experiencing depression and anxiety, vitamin D supplementation may boost mood by rectifying serum 25(OH)D levels. This study assessed the potential for vitamin D to alleviate symptoms of depression and anxiety in colorectal cancer patients with insufficient clinical evidence available.
Materials and Methods: In this study, 46 colorectal adenocarcinoma patients were included based on specific inclusion criteria. Serum 25(OH)D levels were assessed using enzyme-linked immunosorbent assay and assessed anxiety and depression using Zung's questionnaire at baseline. Based on the baseline serum 25(OH)D levels, patients were categorized into four groups of < 12 ng/ml, 12–20 ng/ml, 20–30 ng/ml and ≥ 30 ng/ml. A standard dose of vitamin D supplementation was administered based on the study protocol. After 12 w, serum 25(OH)D levels, anxiety and depression were assessed and statistical analyses were carried out.
Results: In this clinical trial, 80% of patients (median age, 56.8 y) had inadequate baseline serum 25(OH)D levels (< 30 ng/ml), with 28.3% having depressive symptoms (Zung SDS score > 50) and 37% showing anxiety symptoms (Zung SAS score ≥ 40). The average serum 25(OH)D level increased from 25.4 ng/ml before the intervention to 34.8 ng/ml post-intervention. Significant differences were reported in serum 25(OH)D levels before and after the intervention (p = 0.0001). Additionally, significant decreases were reported in the mean scores for anxiety (p = 0.021) and depression (p = 0.015) after the intervention. Changes in serum 25(OH)D levels were significant and inversely correlated with changes in depression (p = 0.0186) and anxiety (p = 0.0099) scores.
Conclusions: Vitamin D supplementation may significantly improve depression and anxiety symptoms in colorectal adenocarcinoma patients.
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