Association of vitamin D levels with type 2 diabetes in older working adults

Determinants of Vitamin D deficiency among type 2 diabetes mellitus patients: A retrospective study

Recent studies have shown an association between vitamin D deficiency (VDD) and type 2 diabetes mellitus patients (T2DM), but the precise relationship between these conditions has yet to be clarified. In this study, we aimed to estimate the incidence of VDD among diabetic patients and identify any relationship between diabetes and the determinants of VDD among T2DM individuals. A retrospective cross-sectional study was conducted at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Patients of either gender were selected from electronic records and checked for vitamin D levels, glycosylated hemoglobin (HbA1c), and other parameters. A total of 864 subjects were enrolled. Subjects were grouped according to HbA1c levels, with < 5.7%, 5.7% to 6.49%, and > 6.5% considered normal, impaired, and diabetic, respectively. VDD was common, with an incidence of 723 (83.7%) subjects. A significantly lower vitamin D level was found in diabetic subjects than in nondiabetic subjects (29.1 ± 12.0 vs 44.0 ± 28.3, P < .001). A total of 207/209 (99%) subjects with impaired HbA1c and 179/183 (97.8%) people with diabetes had VDD. Interestingly, none of the diabetic or impaired HbA1c subjects had normal vitamin D levels. A significant association was found between VDD and being > 50 years old, overweight, or obese, as well as HbA1c, fasting plasma glucose, calcium, and total cholesterol (TC) levels. A high rate of VDD and significantly lower vitamin D levels were found in diabetic subjects. Age, being overweight, obesity, HbA1c, and fasting plasma glucose were the few determinants of VDD among T2DM patients. These findings highlight the importance of addressing vitamin D status in managing and preventing T2DM, particularly in those over the age of 50, those who have higher body weight, and those with raised HbA1c and fasting plasma glucose levels.

Vitamin D Serum Levels in Type 2 Diabetic Patients: A Cross-Sectional Study

Background and objective

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by hyperglycemia. It is linked with an increase in morbidity (e.g., blindness, kidney failure, stroke, cardiovascular diseases, limb amputations), premature mortality, high healthcare costs, and is quickly becoming a global epidemic disorder. Several studies have shown that vitamin D supplements reduce insulin resistance in T2DM and improve insulin secretion and sensitivity. In this study, we aimed to determine the prevalence of vitamin D deficiency in T2DM patients in Saudi Arabia.

Methods

This was a retrospective cross-sectional study conducted at the King Faisal University Health Centre in Saudi Arabia. The study used patient data during the period from October 2014 to January 2021. After obtaining approval from the King Faisal University Polyclinic Administration, we collected patient data from the King Faisal University Health Centre. The Ethics and Research Committee at the College of Medicine of King Faisal University granted ethical approval with the approval number (2020-11-82). The relevant patient data were collected, including age, gender, nationality, and blood test findings (vitamin D and HbA1c levels).

Results

A total of 191 T2DM patients participated in this study. The mean age of the patients was 56.1 ± 11.4 years (range: 21-85 years); 107 (56%) patients were females, and 137 (71.7%) were Saudis. There were 134 (70.2%) patients with vitamin D deficiency, 53 (27.7%) with vitamin D insufficiency, and only four (2.1%) with normal vitamin D levels.

Conclusion

Based on our findings, the prevalence of vitamin D deficiency among T2DM patients is highly associated with poor diabetic control.

On the anti-correlation between COVID-19 infection rate and natural UV light in the UK

While it is well established that the rate of COVID-19 infections can be suppressed by social distancing, environmental effects may also affect it. We consider the hypothesis that natural Ultra-Violet (UV) light is reducing COVID-19 infections by enhancing human immunity through increasing levels of Vitamin-D and Nitric Oxide or by suppressing the virus itself. We focus on the United Kingdom (UK), by examining daily COVID-19 infections (F) and UV Index (UVI) data from 23 March 2020 to 10 March 2021. We find an intriguing empirical anti-correlation between log10(F) and log10(UVI) with a correlation coefficient of -0.934 from 11 May 2020 (when the first UK lockdown ended) to 10 March 2021. The anti-correlation may reflect causation with other factors which are correlated with the UVI. We advocate that UVI should be added as a parameter in modelling the pattern of COVID-19 infections and deaths. We started quantifying such correlations in other countries and regions.

Association of Telomere Length and Serum Vitamin D Levels with Type 2 Diabetes Mellitus and its Related Complications: A Possible Future Perspective

Evidence show that shortened telomere length (TL) and low Vitamin D levels can increase the risk of type 2 diabetes mellitus (T2DM) and its associated complications. T2DM has been considered as an age-related disease, it may be associated with TL. The study aimed to evaluate the association of TL and Vitamin D levels with complications of T2DM and the impact of Vitamin D on TL in patients with T2DM. This 1-year cross-sectional study was conducted at a tertiary care hospital on 90 patients. Height, weight, body mass index, waist-hip ratio was calculated. Fasting blood sugars, postprandial blood sugar, and glycated hemoglobin (HbA1c) were analyzed. Absolute TL was obtained from quantitative real-time polymerase chain reaction (qPCR). Vitamin D estimation was done by chemiluminescent immunoassay. Descriptive analysis of the data was done using R i386 3.6.3. The study found a positive correlation between TL and Vitamin D levels (r = 0.64; P < 0.0001). The interaction with high HbA1c levels and lower levels of Vitamin D led to the shortening of TL (P = 0.0001). The median of TL and mean of Vitamin D levels were significantly less in the diabetic group (P < 0.0001). Vitamin D levels positively affected the TL and its levels had an inverse relation with the HbA1c levels. This association had a significant effect on the shortening of TL. Vitamin D also had a significant association with other diabetic complications that instigated the shortening of TL. Therefore, assessing the role of Vitamin D levels on the shortening of TL can prove to be crucial biomarkers in managing optimal glycemic levels in T2DM patients.

Essential sufficiency of zinc, ω-3 polyunsaturated fatty acids, vitamin D and magnesium for prevention and treatment of COVID-19, diabetes, cardiovascular diseases, lung diseases and cancer

Despite the development of a number of vaccines for COVID-19, there remains a need for prevention and treatment of the virus SARS-CoV-2 and the ensuing disease COVID-19. This report discusses the key elements of SARS-CoV-2 and COVID-19 that can be readily treated: viral entry, the immune system and inflammation, and the cytokine storm. It is shown that the essential nutrients zinc, ω-3 polyunsaturated fatty acids (PUFAs), vitamin D and magnesium provide the ideal combination for prevention and treatment of COVID-19: prevention of SARS-CoV-2 entry to host cells, prevention of proliferation of SARS-CoV-2, inhibition of excessive inflammation, improved control of the regulation of the immune system, inhibition of the cytokine storm, and reduction in the effects of acute respiratory distress syndrome (ARDS) and associated non-communicable diseases. It is emphasized that the non-communicable diseases associated with COVID-19 are inherently more prevalent in the elderly than the young, and that the maintenance of sufficiency of zinc, ω-3 PUFAs, vitamin D and magnesium is essential for the elderly to prevent the occurrence of non-communicable diseases such as diabetes, cardiovascular diseases, lung diseases and cancer. Annual checking of levels of these essential nutrients is recommended for those over 65 years of age, together with appropriate adjustments in their intake, with these services and supplies being at government cost. The cost:benefit ratio would be huge as the cost of the nutrients and the testing of their levels would be very small compared with the cost savings of specialists and hospitalization.

Association of vitamin D receptor polymorphisms with metabolic syndrome-related components: A cross-sectional study

BACKGROUND

The association between vitamin D receptor (VDR) polymorphisms and metabolic syndrome (MS) has been demonstrated by epidemiological studies while their correlation remain controversial. The aim of this study is to investigate the association of VDR gene polymorphisms with MS and MS-related components in the two communities of Hangzhou.

METHODS

A total of 394 subjects were enrolled in the cross-sectional study. Four VDR gene polymorphisms (ApaI, BsmI, FokI, and TaqI) were selected based on human genome sequence databases and genotyped using the MassARRAY Analyzer Compact.

RESULTS

In lipid profile, the TT genotype of ApaI had a significantly lower risk of hypertriglyceridemia compared with the GG+GT genotypes (recessive model: OR = 0.141; 95% CI = 0.041-0.486; p < 0.01) and the GG genotype (codominant model: OR = 0.155; 95% CI = 0.044-0.545; p < 0.01). The levels of triglyceride (TG) in the TT genotype of ApaI were lower than the GG+GT genotypes (1.29 ± 0.63 vs. 1.78 ± 1.59 mmol/L, p < 0.01). Furthermore, the AA+GA carriers of BsmI had lower levels of high-density lipoprotein cholesterol (HDL-C) than the GG carriers (1.28 ± 0.29 vs. 1.42 ± 0.34 mmol/L, p < 0.05). The CC+TC carriers of TaqI also suffered from lower HDL-C compared with the TT carriers (1.27 ± 0.29 vs. 1.42 ± 0.34 mmol/L, p < 0.01). For arterial blood pressure, the CC carriers had lower systolic blood pressure (SBP) than the TT+TC carriers (p < 0.01) and the TT carriers of FokI (p < 0.05). However, the FokI polymorphisms were not associated with SBP and the mean blood pressure of both groups laid within the normal range.

CONCLUSIONS

In our study, VDR polymorphisms show no association with the MS risk. The present results suggest that the VDR ApaI polymorphism is associated with hypertriglyceridemia and predisposed to developing MS, while the variants of BsmI and TaqI seem to affect HDL-C. Nevertheless, the effect of FokI variants with SBP is ambiguous.

The role of vitamin D in prevention of type 2 diabetes. A meta-analysis

BACKGROUND AND AIMS

Recently, there are evidences that have shown vitamin D homeostasis has an impact in the development of type 2 diabetes. However, still it is unclear if vitamin D supplementation reduces the risk of overt diabetes. This meta-analysis of cross-sectional studies and RCTs was conducted to evaluate the role of vitamin D in prevention of type 2 diabetes and to elucidate this controversial topic.

METHODS

A systematic search for English-language literature was done via PUBMED/Medline and Google Scholar up to March 2020. Based on a fixed and random effects model, the OR, HR and 95% CI were used to evaluate the combined risk. This study followed Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) Guidelines.

RESULTS

After eligibility assessment 10 studies with a total of 34,882 participants were included in meta-analysis. Meta-analysis of cross-sectional studies suggested that there was a statistically significant association between the vitamin D and type 2 Diabetes; the pooled OR (95%CI) was 1.77 [1.51, 2.07] (P < 0.001). Meta-analysis of RCTs have shown that there was no statistically significant association between vitamin D supplementation and prevention of type 2 Diabetes, the pooled HR (95%CI) was 0.89 [0.77, 1.02] (P = 0.08).

CONCLUSION

In conclusion, this meta-analysis suggests that there is association between the vitamin D and type 2 diabetes. However, the result of RCTs suggests emphasis of future studies for genetic factors such as polymorphic variants of the VDR gene as one factor in this complex process.

Perspective: Vitamin D deficiency and COVID-19 severity - plausibly linked by latitude, ethnicity, impacts on cytokines, ACE2 and thrombosis

BACKGROUND

SARS-CoV-2 coronavirus infection ranges from asymptomatic through to fatal COVID-19 characterized by a 'cytokine storm' and lung failure. Vitamin D deficiency has been postulated as a determinant of severity.

OBJECTIVES

To review the evidence relevant to vitamin D and COVID-19.

METHODS

Narrative review.

RESULTS

Regression modelling shows that more northerly countries in the Northern Hemisphere are currently (May 2020) showing relatively high COVID-19 mortality, with an estimated 4.4% increase in mortality for each 1 degree latitude north of 28 degrees North (P = 0.031) after adjustment for age of population. This supports a role for ultraviolet B acting via vitamin D synthesis. Factors associated with worse COVID-19 prognosis include old age, ethnicity, male sex, obesity, diabetes and hypertension and these also associate with deficiency of vitamin D or its response. Vitamin D deficiency is also linked to severity of childhood respiratory illness. Experimentally, vitamin D increases the ratio of angiotensin-converting enzyme 2 (ACE2) to ACE, thus increasing angiotensin II hydrolysis and reducing subsequent inflammatory cytokine response to pathogens and lung injury.

CONCLUSIONS

Substantial evidence supports a link between vitamin D deficiency and COVID-19 severity but it is all indirect. Community-based placebo-controlled trials of vitamin D supplementation may be difficult. Further evidence could come from study of COVID-19 outcomes in large cohorts with information on prescribing data for vitamin D supplementation or assay of serum unbound 25(OH) vitamin D levels. Meanwhile, vitamin D supplementation should be strongly advised for people likely to be deficient.

Is the shielding effect of cholecalciferol in SARS CoV-2 infection dependable? An evidence based unraveling

Despite being announced as a global health concern and emergency in January by WHO, designing specific treatment for SARS-CoV-2 is still a summit yet to be conquered. Currently, many drugs are being tested in the clinical scenario and vitamins play a significant role in therapeutic management. Based on the available evidence, we postulate that maintaining normal vitamin D₃ levels may reduce severity, mortality risk of COVID-19. This review elucidates the alarming need for randomized clinical trials to determine the role of vitamin D in patient prognosis in COVID-19 infection and on latitude bases epidemiological outcome.

Editorial: low population mortality from COVID-19 in countries south of latitude 35 degrees North supports vitamin D as a factor determining severity

LINKED CONTENT This article is linked to Al‐Ani et al and Garg et al papers. To view these articles, visit https://doi.org/10.1111/apt.15779 and https://doi.org/10.1111/apt.15796.

A Potential Linking between Vitamin D and Adipose Metabolic Disorders

Vitamin D has been discovered centuries ago, and current studies have focused on the biological effects of vitamin D on adipogenesis. Besides its role in calcium homeostasis and energy metabolism, vitamin D is also involved in the regulation of development and process of metabolic disorders. Adipose tissue is a major storage depot of vitamin D. This review summarized studies on the relationship between vitamin D and adipogenesis and furthermore focuses on adipose metabolic disorders. We reviewed the biological roles and functionalities of vitamin D, the correlation between vitamin D and adipose tissue, the effect of vitamin D on adipogenesis, and adipose metabolic diseases. Vitamin D is associated with adipogenesis, and vitamin D supplements can reduce the burden caused by metabolic diseases. The review provides new insights and basis for medical therapy on adipose metabolic diseases.

The optimal vitamin D cut-off value associated with hyperglycemia in an Iranian population

Background

Vitamin D deficiency may accelerate the risk of type 2 diabetes mellitus. The association of vitamin D with hyperglycemia may be influenced by lifestyle.

Objective

To evaluate the relationship between vitamin D status and hyperglycemia among the workers' population.

Methods

This was a medical records review of 7054 Iranian factory workers participating in an annual health check-up for employees. Of those, potential participants were included in this analysis if data for serum 25-hydroxyvitamin D [25(OH) D] levels were also available.

Results

Data of 429 male participants were used for this analysis. Of those, 61.07% had serum 25(OH)D concentrations lower than the sufficient level [≥20 ng/ml]. Hyperglycemic participants had significantly lower 25(OH)D than those with normal fasting blood glucose (FBG). Regression analyses highlighted serum 25(OH)D as a significant determinant of hyperglycemia [OR: 0.943(0.901, 988); p = 0.01]. The association between 25(OH)D and FBG remained significant after adjustment for potential confounders (p = 0.008). Using the ROC analysis, the serum 25(OH)D value of 14.7 ng/ml was the optimal cut-off point to predict hyperglycemia in this population (sensitivity: 63.6%, specificity: 62.3%, p = 0.01).

Conclusion

Our results revealed a considerable proportion of participants with serum 25(OH)D below the optimal level as well as a significant inverse association between vitamin D status and hyperglycemia among the factory workers. These findings highlight the importance of including the evaluation of vitamin D status as a part of annual health examinations for employees, and may help health policy- makers prevent or delay type 2 diabetes mellitus among the workers' population.

Study of relationship between total vitamin D level and NAFLD in a sample of Egyptian patients with and without T2DM

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is increasing recently due to increasing the prevalence of obesity. Insulin resistance (IR) is the mutual pathological cause for both T2DM and NAFLD. Vitamin D acts against IR by its anti-inflammatory and regulation of insulin secretion as pancreatic beta cells express vitamin D receptor (VDR).

AIM

Assessment of relationship between Total vitamin D level and NAFLD a sample of Egyptian patients with and without T2DM.

METHODS

The current study included 110 Egyptian subjects. They divided into 4 groups: Group 1: 30 diabetic patients with NAFLD Group 2: 30 diabetic patients without NAFLD Group 3: 30 NAFLD patients without diabetes Group 4: 20 healthy controls. Vitamin D level assessment, AST, ALT, GGT, total cholesterol, LDL, triglycerides, fasting and 2 h post prandial plasma glucose, glycosylated hemoglobin, albumin and creatinine calculation of FLI were assessed.

RESULT

There was a statistical significant decrease in total vitamin D level in T2DM patients with NAFLD than either T2DM or NAFLD only patients.(15.5 ± 7.46 vs 24.4 ± 8.19 and 22.86 ± 9.58 ng/ml respectively) also Total vitamin D level is negatively correlated with age, weight, BMI, WC, total cholesterol, LDL, TG, FPG, HbA1c and FLI.

CONCLUSION

There is a decrease in total vitamin D in T2DM patients with NAFLD.

NIPA2 regulates osteoblast function via its effect on apoptosis pathways in type 2 diabetes osteoporosis

Type 2 diabetes osteoporosis has recently become a hot topic in the study of diabetic complications, but the specific mechanism of its development remains unclear. Non-imprinted in Prader-Willi/Angelman syndrome region protein 2 (NIPA2), a highly-selective magnesium ion transporter, has been found to be associated with type 2 diabetes. In this study we aimed to investigate the specific role and mechanism of NIPA2 in the pathogenesis of type 2 diabetes osteoporosis. We first used western blotting, PCR, immunofluorescence, and magnesium ion probes to detect changes of NIPA2 and intracellular magnesium levels in osteoblasts at different concentrations of advanced glycation end products (AGEs). We then up- or down-regulated NIPA2 using a lentivirus and analyzed apoptotic biomarkers as well as the osteogenic ability of osteoblasts. We found that AGEs dose-dependently down-regulated the expression of NIPA2 in osteoblasts. NIPA2 also regulated osteoblast apoptosis by affecting the intracellular magnesium level and further affecting the osteogenic capacity of osteoblasts. Our study revealed the changes of NIPA2 in response to AGEs in the environment, as well as its function and mechanism in osteoblasts, demonstrating its important role in the pathogenesis of type 2 diabetes osteoporosis. The study suggests that NIPA2 is a potential target for the treatment of type 2 diabetes osteoporosis.

Vitamin D and cardiometabolic disorders: a review of current evidence, genetic determinants and pathomechanisms

Vitamin D deficiency has been implicated in the pathophysiology of cardiometabolic disorders including obesity, type 2 diabetes mellitus, cardiovascular diseases and polycystic ovary syndrome. Despite a large number of experimental and observational studies supporting a role for vitamin D in these pathologies, randomized controlled trials have reported little to no effect of vitamin D supplementation in the prevention or treatment of these disorders, although some results remain ambiguous. Polymorphisms in genes related to vitamin D metabolism, particularly in the vitamin D receptor and binding protein and the metabolizing enzyme 1-α-hydroxylase, have emerged as potential contributors to these divergent results. It is now becoming increasingly recognized that the effects and potential benefits of vitamin D supplementation may vary by several factors including vitamin D deficiency status, ethnicity and/or the presence of genetic variants, which affect individual responses to supplementation. However, these factors have seldom been explored in the available literature. Future trials should consider inter-individual differences and, in particular, should aim to clarify whether certain subgroups of individuals may benefit from vitamin D supplementation in the context of cardiometabolic health.

Impact of 1,25(OH) 2 D 3 on TG content in liver of rats with type 2 diabetes

PURPOSE

To evaluate the effects of 1,25 dihydroxy vitamin D3 (1,25(OH)2D3) on the content of triglyceride (TG), as well as on the gene and protein expressions of adiponectin receptor 2 (AdipoR2), p38 mitogen-activated protein kinase (P38MAPK), and lipoprotein lipase (LPL) in the liver of rats with type 2 diabetes mellitus (T2DM) so as to provide theoretical basis for exploring the mechanism by which 1,25(OH)2D3 regulates TG.

METHODS

Wistar rats were divided into four groups (n=25), with different treatments and detected the gene and protein expressions of AdipoR2, p38MAPK, and LPL in the liver tissue by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. Meanwhile, the content of TG in the liver tissue was detected by the Enzyme-linked immunosorbent assay.

RESULTS

The expression of AdipoR2, p38MAPK, LPL gene and protein in the liver of VitD intervention group was significantly higher than that in T2DM group (P <0.05), while the TG content was significantly lower than that in T2DM group (P <0.05).

CONCLUSION

1,25(OH)2D3 can decrease the content of TG in the liver, and its mechanism may be achieved by upregulating the expressions of AdipoR2, p38MAPK, and LPL in the liver.

Vitamin D ratio and glycaemic control in individuals with type 2 diabetes mellitus: A systematic review

Several studies have suggested a favorable role for vitamin D in glycaemic metabolism and its potential as adjuvant treatment of type 2 diabetes mellitus. This review discusses the role of vitamin D in the glycaemic control of individuals with type 2 diabetes mellitus and evaluates the effect of vitamin D supplementation on glycaemic markers in this population. Literature searches were performed in the BIREME, LILACS, and PubMed databases using the Medical Subject Headings and words related to vitamin D, type 2 diabetes mellitus, and glycaemic control. Interventional and observational studies were considered eligible. The evaluation of the included studies was independently performed by 2 evaluators at all stages of selection, data extraction, and bias risk assessment. The primary outcome was the relationship between vitamin D levels and glucose metabolism markers in type 2 diabetes mellitus individuals. The secondary outcome was the effect of vitamin D supplementation on the glycaemic control markers in individuals with type 2 diabetes mellitus. The inverse relationship between vitamin D and variables of glucose metabolism was verified. Interventional studies revealed that vitamin D supplementation did not alter glycaemic control markers in most studies. Few studies have shown positive effects with a significant reduction in the percentage of glycated haemoglobin, insulin, and glucose concentrations, and changes in homeostatic model assessment-insulin resistance and beta cell, and quantitative insulin sensitivity check index. Therefore, despite the association of vitamin D with glucose metabolism, there is insufficient evidence of the beneficial effects of its supplementation on the metabolic control of type 2 diabetes mellitus.

Prevalence of vitamin D deficiency and its associated factors among the urban elderly population in Hyderabad metropolitan city, South India

BACKGROUND

Deficiency of vitamin D has been associated with various health conditions. However, vitamin D deficiency (VDD) and factors associated with VDD are not well studied, especially among the urban elderly population of India.

AIM

To assess the prevalence of VDD and its associated factors among the urban free-living elderly population in Hyderabad.

SUBJECTS AND METHODS

A community-based cross-sectional study was conducted among 298 urban elderly (≥60 years) by adapting a random sampling procedure. Demographic particulars were collected. Blood pressure and anthropometric measurements were recorded using standard equipment. Fasting glucose, lipid profile and 25-hydroxy vitamin D [25(OH) D] were estimated in plasma samples.

RESULTS

The mean ± SE plasma vitamin D and the prevalence of VDD among the urban elderly population were 19.3 ± 0.54 (ng/ml) and 56.3%, respectively. The prevalence of VDD was significantly associated with education, high body mass index (BMI), hypertension (HT) and metabolic syndrome (MS). Multiple logistic regression analysis revealed HT as a significant predictor of vitamin D deficiency and the risk of VDD was double among the elderly with hypertension.

CONCLUSIONS

The prevalence of VDD was high among the urban elderly population in the south Indian city of Hyderabad. High BMI, MS, HT and education are significant associated factors of VDD.

Is Hypovitaminosis D Related to Incidence of Type 2 Diabetes and High Fasting Glucose Level in Healthy Subjects: A Systematic Review and Meta-Analysis of Observational Studies

There is evidence that vitamin D status is associated with type 2 diabetes. Many observational studies have been performed investigating the relationship of vitamin D status and circulating biomarkers of glycemic regulation. To find out whether this association holds, we conducted a systematic review and meta-analysis of cross sectional and longitudinal studies. We searched Pubmed, Medline and Embase, all through June 2017. The studies were selected to determine the effect of vitamin D on the parameters of glucose metabolism in diabetic and non-diabetic subjects. Correlation coefficients from all studies were pooled in a random effects meta-analysis. The risk of bias was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. We found significant inverse relationship of vitamin D status with glycemic level in both diabetic (r = -0.223, 95% CI = -0.184 to -0.261, p = 0.000) and non-diabetic (r = -0.073, 95% CI = -0.052 to -0.093, p = 0.000) subjects. This meta-analysis concludes that hypovitaminosis D is associated with increased risk of hyperglycemia both in diabetic and non-diabetic subjects. A future strategy for the prevention of impaired glycemic regulation could be individualized supplementation of vitamin D.

Association between low serum 25-hydroxyvitamin D and depression in a large sample of Chinese patients with type 2 diabetes mellitus

BACKGROUND

Because of the absence of data on the direct association between vitamin D and depression in patients with diabetes, we examined the association between vitamin D state (assessed by 25-hydroxyvitamin D [25(OH)D]) and the prevalence of depression in adult patients with type 2 diabetes mellitus(T2DM).

METHOD

Cross-sectional data were obtained from 2786 patients with T2DM recruited from a Chinese diabetes registry. Patients' records were reviewed to obtain data pertaining to age, sex, Body Mass Index (BMI), marital status, level of education, smoking status, duration of diabetes mellitus, use of insulin, and presence of additional illnesses. A multiple logistic regression analysis adjusted for potential confounders was used to assess independent associations between serum levels of 25 (OH)D and depression (defined by the Patient Health Questionnaire-9).

RESULTS

Using the PHQ-9 cutoff value of ≥10, 5.71% (159/2786; 95% CI: 4.85-6.57%) were considered to have depression. The serum 25(OH)D levels were significantly lower in diabetic patients with depression than those patients without depression [10.2(IQR, 7.6-15.2)ng/ml vs. 14.6(IQR, 10.7-19.8)ng/ml, respectively; P<0.0001]. Multivariate logistic regression analysis considering traditional risk factors and other biomarkers showed an inverse relationship between serum 25 (OH)D levels and depression when serum 25 (OH)D were used as a continuous variable (OR, 0.84; 95% CI, 0.77-0.90; P<0.001). Compared with the first quartile of serum 25 (OH)D levels, the second quartile OR for depression was 0.83 (95% CI, 0.75-0.92, P=0.012). For the third and fourth quartiles, it was 0.40 (95% CI, 0.33-0.52, P<0.001) and 0.15 (95% CI, 0.08-0.22; P<0.001), respectively.

CONCLUSIONS

We observed a significant negative association between serum levels of 25 (OH)D and depression in Chinese patients with T2DM.

Association between Obesity and Serum 25(OH)D Concentrations in Older Mexican Adults

Background: Vitamin D is essential for maintaining bone mineralization and calcium homeostasis, and prevents falls and fractures in older adults. Mexico is undergoing an epidemiologic and demographic transition with increasing obesity rates. The study’s aim was to determine the association of obesity with serum 25-hydroxyvitamin D [25(OH)D] concentrations in older Mexican adults. Methods: Data from 1772 Mexicans, aged ≥50 years, enrolled in a sub-sample of the 3rd wave of the Mexican Health and Aging Study, were included. Serum 25(OH)D concentrations were used to define vitamin D status, and were categorized into tertiles. Body mass index measures were used to categorize older adults into under/normal weight, overweight, and obese groups. Multinomial logistic regression models were used to assess the relationship, adjusting for potential confounders. Results: Approximately 40% and 37% of older Mexican adults were either overweight or obese, respectively. Compared to under/normal weight older Mexicans, obese adults were 1.78 times (95% Confidence Interval (CI) 1.27–2.48) and 1.94 times (95% CI 1.40–2.68) more associated with the first and second tertile concentrations of serum 25(OH)D, respectively. Overweight adults were 1.52 times (95% CI 1.12–2.06) more associated with the second tertile of serum 25(OH)D concentration than under/normal weight adults. Conclusion: Overweight/Obesity was found to be significantly associated with low concentrations of serum 25(OH) in older Mexican adults.

Effects of Vitamin D deficiency treatment on metabolic markers in Hashimoto thyroiditis patients

Background:

The aim of the current trial was to investigate the effect of Vitamin D treatment on metabolic markers in people with Vitamin D deficiency and thyroid autoimmunity.

Materials and Methods:

In this double-blind, randomized, placebo-controlled clinical trial, 65 Vitamin D deficient euthyroid or hypothyroid patients with positive TPO-Ab were enrolled. They randomly allocated into two groups to receive oral Vitamin D_{3 (}50000 IU weekly) and placebo for 12 weeks. Serum concentration of calcium, phosphorus, albumin, C-reactive protein, blood urea nitrogen, creatinine, glycated hemoglobin (HbA1c), insulin, fasting plasma glucose (FPG), triglyceride (TG), total cholesterol, and high-density lipoprotein were measured in both groups before and after the trial. Homeostasis model assessment estimates of beta cell function (HOMA-B) and HOMA-insulin resistance (HOMA-IR) were calculated before and after trial in both groups.

Results:

Thirty-three and thirty-two participants were allocated to Vitamin D-treated and placebo-treated groups, respectively. Mean (standard error) level of Vitamin D increased significantly in Vitamin D-treated group (45.53 [1.84] ng/mL vs. 12.76 [0.74] ng/mL, P = 0.001). The mean of HbA1c and insulin was increased significantly both in Vitamin D-treated and placebo-treated groups (P < 0.05). Other variables did not meet a significant change after trial (P = NS). In between-group comparison, there was not any significant difference between Vitamin D-treated and placebo-treated groups regarding measures of HOMA-B, HOMA-IR, FPG, HbA1c, and TG (P = NS).

Conclusion:

Our findings showed that weekly 50000 IU oral Vitamin D3 for 12 weeks did not improve metabolic markers, IR, or insulin secretion in Vitamin D deficient patients with Hashimoto thyroiditis.

Association between the BsmI Polymorphism in the Vitamin D Receptor Gene and Breast Cancer Risk: Results from a Pakistani Case-Control Study

BACKGROUND

Vitamin D is postulated to decrease the risk of breast cancer by inhibiting cell proliferation via the vitamin D receptor (VDR). Two common single nucleotide polymorphisms (SNPs) in the VDR gene, rs1544410 (BsmI) and rs2228570 (FokI), are inconsistently associated with breast cancer risk in Caucasian populations, while data for Asians are scarce. Here, we investigated the possible contribution of these SNPs to breast cancer risk in Pakistani breast cancer patients and in controls participating in a hospital-based breast cancer case-control study (PAK-BCCC).

METHODS

Genotyping of the BsmI and FokI SNPs was performed by PCR-based restriction fragment length polymorphism (RFLP) analysis of 463 genetically enriched female breast cancer cases with known BRCA1/2 status and in 1,012 controls from Pakistan. The association between SNP genotypes and breast cancer risk was investigated by logistic regression adjusted for potential breast cancer risk factors and stratified by BRCA1/2 status and family history. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported.

RESULTS

The b allele of the BsmI was associated with an increased breast cancer risk (per b allele OR 1.28, 95% CI 1.09-1.49, P = 0.003). Subgroup analysis revealed that this effect was restricted to BRCA1/2 non-carriers (per b allele OR 1.33, 95% CI 1.11-1.59, P = 0.002) and was stronger in those who reported a positive family history of breast and/or ovarian cancer (per b allele OR 1.64, 95% CI 1.20-2.22, P = 0.002). No association with breast cancer risk was detected for the FokI SNP.

CONCLUSIONS

The BsmI polymorphism in the VDR gene may be associated with an increased breast cancer risk in Pakistani women negative for BRCA1/2 germline mutations.