Effect of vitamin D supplementation on type 2 diabetes biomarkers: an umbrella of interventional meta-analyses

Effects of vitamin D supplementation on metabolic parameters in women with polycystic ovary syndrome: a randomized controlled trial

OBJECTIVE

The aim of this study was to explore the effects of vitamin D supplementation on metabolic parameters in women with polycystic ovary syndrome (PCOS).

METHODS

A total of 60 PCOS women with vitamin D deficiency or insufficiency were enrolled in this randomized controlled trial. Participants were randomized to vitamin D group (2000 IU/day) or control group. The observational parameters were measured at baseline and after treatment, including body mass index (BMI), waist to hip ratio (WHR), oral glucose tolerance test (OGTT) and insulin release test, and lipid metabolism parameters.

RESULTS

The serum 25(OH)D concentrations at different time points after vitamin D supplementation were significantly higher than that in control group (P < 0.05). The BMI, WHR, insulin concentrations, homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) concentrations in women of Vitamin D group after 12 weeks of treatment were significantly lower than that in women of control group (P < 0.05). The serum insulin concentrations and HOMA-IR at different time points of OGTT, serum TG, TC and LDL-C concentrations in women of vitamin D group (obesity) were significantly lower compared with control group (obesity) (P < 0.05). The BMI, WHR, TG, TC and LDL-C concentration in women of vitamin D group (IR) were significantly lower compared with control group (IR) (P < 0.05). No significant difference was observed in metabolic parameters between vitamin D group (non-obesity) and control group (non-obesity) (P > 0.05), and these differences of metabolic parameters were also not observed between vitamin D group (non-IR) and control group (non-IR) (P > 0.05).

CONCLUSION

Vitamin D supplementation had beneficial effects on metabolic parameters in PCOS women, especially in women with obesity or insulin resistance.

Relationship Between Glycated Hemoglobin (HbA1c) and Vitamin D Levels in Type 2 Diabetes Patients: A Retrospective Cross-Sectional Study

BACKGROUND

Significant links between low serum levels of vitamin D3 and insufficient glycemic control in patients with type 2 diabetes mellitus (T2DM) have been reported previously in the literature. However, there is no exciting evidence on the association between glycated hemoglobin (HbA1c) and vitamin D levels in T2DM individuals in our nation (Yemen). This study aimed to investigate the relationship between HbA1c and vitamin D levels in T2DM patients in a resource-limited setting.

METHOD

A retrospective cross-sectional study was conducted at the Al-Raffa Center, Ibb, Yemen between June 2018 and September 2023 including 396 patients diagnosed with T2DM. The patient characteristics, comorbidities, HbA1c, and vitamin D levels were gathered from patients' medical profiles. Linear regression analysis was used to find the factors associated with vitamin D deficiency (serum 25(OH)D levels < 20 ng/mL) among T2DM patients. Subsequently, the correlation between HbA1c and vitamin D levels was examined using receiver operating characteristic (ROC) curve analysis.

RESULTS

The mean age was 44.6 ±14.6 years and most of them (n= 227, 57.3%) were female and from a rural area (n= 229, 57.8%). Comorbidities were hypertension, dyslipidemia disease, and cardiovascular disease in 176 (44.4%), 63 (15.9%), and 88 (22.2%) cases, respectively. The mean HbA1c was 8.1 ±2.5%. The mean vitamin D level was 26.9 ±16.5 ng/mL and low vitamin D was present in 260 (65.7%) (vitamin D deficiency in 160 (40.4%) and vitamin D insufficiency in 100 (25.3%) cases). In regression analysis, obesity (>30 kg/m2) (odds ratio (OR): 299.49; 95% confidence interval (CI): 72.66 - 1234.42, p <0.0001), higher HbA1c levels (OR: 1.61; 95% CI: 1.26 - 2.05, p =0.0001), and urban residence (OR: 23.98; 95% CI: 5.62 - 102.42, p <0.0001) were associated with vitamin D deficiency. There was a negative correlation between the vitamin D level and HbA1c which was statistically significant (correlation coefficient r: -0.5452; 95% CI: -0.6109 to -0.4720, p <0.0001). Using the ROC analysis, the serum vitamin D value of ≤18.42 ng/ml was the best cut-off point to predict hyperglycemia (area under the curve: 0.633, 95% CI: 0.672 to 0.770, sensitivity: 52%, specificity: 84.71 %, Yoden's index: 0.3671, p <0.001). Based on this cut-off, 39.4% of individuals (37.5% in the normoglycemic group and 90.9% in the hyperglycemic group) were vitamin D deficient.

CONCLUSION

In this study, low vitamin D was common among T2DM patients, especially those with poor glycemic control. We observed a link between HbA1c levels, urban residency, and BMI with vitamin D deficiency in T2DM patients. The association was distinguished by low vitamin D levels and elevated HbA1c. Additionally, we found that the serum vitamin D value of ≤18.42 ng/ml was the best cut-off point to predict hyperglycemia in T2DM patients with moderate agreement. To manage their disease, patients with T2DM should take their medications as prescribed and live a healthy lifestyle. This will increase their overall health, especially their vitamin D levels.

Nutritional Challenges in Nursing Homes: Pilot Study on Macronutrient Intake and Status of Vitamins D and B12

Older adults living in nursing homes (NH) are considered a population group that could be at risk in terms of nutrition, even more so than their community-dwelling peers. Evidence on the nutritional status of NH residents is scarce, as they are commonly excluded from population-based dietary studies. This is also the case in Slovenia. In the presented pilot study, we assessed the intake of macronutrients as well as the intake and status of vitamin D and vitamin B12 on a sample of NH and NH daycare center users to explore the need for a larger representative study. The pilot study included 37 participants from three Slovenian NH (20 participants) and their daycare centers (17 participants). Daycare centers offer daytime care services for older adults, where users are also provided with major meals during their stay. Intakes of energy and nutrients were estimated by three 24 h dietary records. Fasting blood samples were collected for the assessment of vitamin D and vitamin B12 status. Over 90% of the participants had daily energy and protein intakes below recommendations (reference values: energy intake: males 2100 kcal and females 1700 kcal; protein intake > 1 g/kg body mass). The males' median daily intakes of vitamin D were 1.7 µg (1.5 µg females), and 2.3 µg for vitamin B12 (2.0 µg females). None of the participants had adequate vitamin D intake (>20 µg), and 92.3% males and 87.5% females had inadequate vitamin B12 intake (<4 µg). The prevalence of vitamin D deficiency (serum 25-OH-D conc. < 30 nmol/L) was 100% among NH residents and 53% among NH daycare center users. The prevalence of vitamin B12 deficiency was found in 20% of NH residents. The study results highlighted that certain nutrients might be critical in this population, especially among NH residents; however, a more thorough investigation with the inclusion of other important markers of nutritional status should be performed on a larger, representative sample to support the development and implementation of appropriate public health interventions.

Two-Month Consumption of Orange Juice Enriched with Vitamin D3 and Probiotics Decreases Body Weight, Insulin Resistance, Blood Lipids, and Arterial Blood Pressure in High-Cardiometabolic-Risk Patients on a Westernized Type Diet: Results from a Randomized Clinical Trial

This study examined the effects of orange juice (OJ) supplemented with vitamin D3 (2000 IU) and probiotics (Lacticaseibacillus casei Shirota and Lacticaseibacillus rhamnosus GG, 108 cfu/mL) on cardiometabolic risk factors in overweight and obese adults following a Westernized-type diet. Fifty-three high-risk individuals were randomly assigned to one of two groups. Over 8 weeks, one group consumed a vitamin D3 and probiotic-enriched OJ and the other regular OJ (control). Diets remained unchanged and were documented through food diaries. Measures of metabolic and inflammatory markers and blood pressure were measured at the start and end of the study. Post-intervention, the enriched OJ group showed the following significant metabolic improvements (without changes in triglycerides, inflammation, or central blood pressure): reduced fasting insulin, peripheral blood pressure, body weight (-1.4 kg 95% CI: -2.4, -0.4), energy (-270 kcal 95% CI: -553.2, -13.7), macronutrient (dietary fat -238 kcal 95% CI: -11.9, -1.0; carbohydrates -155 kcal 95% CI: -282.4, -27.3; sugars -16.1 g 95% CI: -11.9, -1.0) intake, and better lipid profiles (total cholesterol -10.3 mg/dL 95% CI: -21.4, 0.9; LDL-C -7 mg/dL 95% CI: -13.5, -0.5). The enriched OJ led to weight loss, less energy/macronutrient consumption, improved lipid profiles, and increased insulin sensitivity after 8 weeks in those following a Westernized diet, thus indicating potential benefits for cardiometabolic risk. This study was a part of FunJuice-T2EDK-01922, which was funded by the EU Regional Development Fund and Greek National Resources.

High glucose-induced injury in human umbilical vein endothelial cells is alleviated by vitamin D supplementation through downregulation of TIPE1

BACKGROUND

Diabetes mellitus (DM) and its associated vascular complications have become a worldwide health concern. The effects and mechanism of vitamin D supplementation on endothelial function under high glucose condition remain elusive.

METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with 35 mM glucose, then 100 nM vitamin D were added. Transwell migration assay, CCK-8, immunofluorescence, flow cytometry, autophagy flux and transmission electric microscope were performed.

RESULTS

Vitamin D reduced apoptosis, promoted migration and enhanced viability of HUVECs, decreased TIPE1 (Tumor necrosis factor-α-induced protein 8-like 1) under high glucose conditions. Overexpression of TIPE1 reverses the effects of vitamin D by increasing ROS production, inflammation, cell apoptosis, and suppressing autophagy, cell migration and viability. And vitamin D negatively correlated with TIPE1 mRNA level in DM patients.

CONCLUSIONS

Vitamin D reverses the harmful effects of high glucose on HUVECs by reducing TIPE1 expression. And vitamin D supplementation could help to alleviate high glucose-induced injury in type 2 diabetes mellitus patients with microvascular complications.

Effects of combined aerobic exercise and diet on cardiometabolic health in patients with obesity and type 2 diabetes: a systematic review and meta-analysis

BACKGROUND

Lifestyle modifications involving diet and exercise are recommended for patients diagnosed with obesity and type 2 diabetes mellitus (T2DM). The purpose of this review was to systematically evaluate the effects of combined aerobic exercise and diet (AEDT) on various cardiometabolic health-related indicators among individuals with obesity and T2DM.

METHODOLOGY

A comprehensive search of the PubMed/Medline, Web of Science, Scopus, Science Direct, Cochrane, and Google Scholar databases was conducted for this meta-analysis. The Cochrane risk of bias tool was used to evaluate eligible studies, and the GRADE tool was used to rate the certainty of evidence. A random-effects model for continuous variables was used, and the results were presented as mean differences or standardised mean differences with 95% confidence intervals.

RESULTS

A total of 16,129 studies were retrieved; 20 studies were included, and data were extracted from 1,192 participants. The findings revealed significant improvements in body mass index, body weight, waist circumference, systolic blood pressure, diastolic blood pressure, total cholesterol, triglycerides, fasting blood glucose, fasting plasma insulin, glycated hemoglobin, leptin, interleukin-6, C-reactive protein, and adiponectin (p < 0.05) compared to the standard treatment (ST) group. No significant differences were observed between the AEDT and ST groups in fat mass, hip circumference, waist-to-hip ratio, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and tumor necrosis factor-alpha. The present findings are based on low- to moderate-quality evidence.

CONCLUSIONS

AEDT may be a critical behavior for holistic cardiometabolic health-related benefits as a contemporary anti-obesity medication due to its significant positive impact on patients with obesity and T2DM. Nevertheless, further robust evidence is necessary to determine whether AEDT is an effective intervention for lowering cardiovascular and metabolic risk factors among individuals with obesity and T2DM.

Could vitamin D concentration be a marker of a long hospital stay in older adults patients?

Background and aims

Vitamin D plays a pleiotropic role in the human body. Some studies have suggested that hypovitaminosis D may serve as a marker of comorbidity severity and length of hospital stay. Hospitalized older adults patients with a higher comorbidity burden tend to have lower vitamin D status, which negatively impacts the length of their hospital stay. Vitamin D deficiency has been identified as a significant risk factor for a prolonged hospital stay. This study aimed to investigate the link between vitamin D status and prolonged hospital stays, focusing on geriatric patients, and to assess the variation in hospitalization duration among geriatric patients with different vitamin D statuses.

Methods

The study sample comprised of 422 patients aged over 60 years admitted to the geriatric department. Blood samples were collected in the morning on the day of admission. According to the diagnostic threshold defining serum 25(OH)D concentration approved for Central Europe, patients were divided into two groups (deficiency group and suboptimal group). Patients were divided into two groups based on hospitalization duration: the first, "shorter hospitalization," included stays up to 11 days, whereas the second, "longer hospitalization," encompassed stays of 12 days and above.

Results

In total, 242 Caucasian patients, primarily women (172 women and 70 men), were recruited in the study. Patients with vitamin D deficiency had extended hospital stays compared with those with vitamin D levels below 49.92 nmol/L: 10.0 (8.00-13.00) days vs. 9.00 (8.00-11.00) days, P = 0.044. Hospitalization length (in days) had a negative correlation with vitamin D blood status (nmol/L) (P = 0.0005; R = -0.2243). ROC analysis indicated that patients with vitamin D levels below 31.2 nmol/L had a 47% higher chance of extended hospitalization, whereas those with levels above 31.2 nmol/L had a 77% higher chance of avoiding it. A significant majority of patients with suboptimal 25(OH)D levels experienced shorter hospital stays (≤11 days) than those with vitamin D deficiency (64.6%), P = 0.045.

Conclusion

The study findings indicate that lower serum levels of 25(OH)D in hospitalized patients within the geriatric department are linked to extended hospital stays. Vitamin D holds potential as a predictor of hospitalization duration in geriatric patients. Nonetheless, further research is imperative to account for additional factors affecting health status and hospitalization duration in older adults individuals.