Body composition in nonobese individuals according to vitamin D level

Effects of vitamin D supplementation on metabolic syndrome parameters in patients with obesity or diabetes in Brazil, Europe, and the United States: A systematic review and meta-analysis

Plasma 25-dihydroxyvitamin D levels appear reduced in patients with obesity or type 2 diabetes, as reported in several observational studies. However, the association between these reduced hormone levels and metabolic parameters is unclear. In any case, vitamin D supplementation in patients with Metabolic Syndrome is standard. Still, the impacts of this supplementation on conditions such as glycemia, blood pressure, and lipidemia are debatable. Based on this question, we carried out a systematic review and meta-analysis of randomized clinical trials in Brazil, Europe, and the United States that analyzed the effects of vitamin D supplementation on Metabolic Syndrome parameters in patients with obesity or type 2 diabetes. Our search yielded 519 articles and included 12 randomized controlled trials in the meta-analysis. Vitamin D supplementation had no effect on any of the outcomes analyzed (fasting blood glucose and insulinemia, glycated hemoglobin, HOMA index, systolic and diastolic blood pressure, weight, waist circumference, total cholesterol, LDL and HDL, and triglycerides). However, subgroup analyses indicated that using vitamin D up to 2000 IU daily reduced participants' fasting blood glucose and glycated hemoglobin. Furthermore, the intervention reduced diastolic blood pressure only in participants with vitamin D deficiency. At least two studies showed a high risk of bias using the Rob2 protocol. According to the GRADE protocol, the evidence quality varied from moderate to very low. These results indicate that vitamin D supplementation does not improve patients' metabolic parameters and that the association between plasma 25-dihydroxyvitamin D levels and Metabolic Syndrome may not be causal but caused by other confounding characteristics. However, in any case, the quality of evidence is still low, and more randomized clinical trials are essential to clarify these relationships.

Serum Vitamin D3 as a Potential Biomarker for Neuronal Damage in Smoldering Multiple Sclerosis

Permanent inflammatory demyelinating and neurodegenerative processes lead to neurological disability in patients with multiple sclerosis (MS). The anti-inflammatory properties of vitamin D3 (VitD) are well established, but its role in neurodegeneration is still uncertain. The usefulness of the serum concentration of VitD as a potential biomarker in evaluating brain injury in terms of recently known smoldering MS was under consideration. Methods: We assessed the concentrations of the parameters of brain injury (NF-H, GPAF, S100B, UCHL1) in the cerebrospinal fluid (CSF) of relapsing-remitting (RRMS, n = 123) and progressive MS (PMS, n = 88) patients in the group with normal levels of VitD (VitDn) and in the VitD deficiency group (VitDd). The levels of NF-H and UCHL1 were higher in the group of VitDd compared to VitDn. The higher serum levels of VitD were correlated with lower concentrations of GFAP, NF-H and S100B in the CSF of the whole group of MS patients and in women with MS as opposed to the levels of UCHL1. In men, there were noted negative correlations between the levels of serum VitD and GFAP and NF-H in CSF but not between VitD and S100B and UCHL1. The negative correlations were observed between VitD and the selected parameters of brain injury in MS patients, in women as well as in men. The concentrations of serum VitD together with selected parameters of brain injury in CSF seem to be promising biomarkers of neurodegeneration processes in smoldering MS.

Lack of awareness and ethnic polarity is a major cause of metabolic associated fatty liver disease in high-risk diabetes population in South London

BACKGROUND

Metabolic associated fatty liver disease (MAFLD) stands as the leading cause of chronic liver disease globally. Notably, individuals with metabolic risk factors, such as diabetes and obesity, exhibit a staggering prevalence of MAFLD, with estimates reaching up to 70%. However, despite its widespread occurrence, there's a noticeable gap in understanding and awareness about MAFLD among these high-risk groups.

OBJECTIVES

The main objective of this study was to assess the awareness and prevalence of MAFLD among diabetic patients who regularly receive secondary care focusing particularly on how multiethnic backgrounds and associated lifestyle preferences influence these health outcomes.

DESIGN

Cross-sectional study.

METHODS

Patients with type 2 diabetes (T2D) who regularly attend Lambeth Diabetes Intermediate Care Team clinics were invited to undergo MAFLD screening using FibroScan. Those who agreed to participate were provided with structured questionnaires on diet, physical activity, and MAFLD knowledge by a hepatologist. For each participant, anthropometric data, medical history, liver stiffness measurement, and controlled attenuation parameter (CAP) were documented. Steatosis was identified with a CAP value of ⩾275 dB/m, and advanced fibrosis was flagged at values of ⩾8 kPa.

RESULTS

The FibroScan data was valid in 96.4% (215), 53.5% (115/215) had steatosis and 26.2% (58/215) had liver fibrosis in this multiethnic high-risk group. Awareness of MAFLD was notably low at 30.9%. Alarmingly, 69% of patients diagnosed with liver fibrosis were unfamiliar with the condition. Additionally, understanding of MAFLD showed variation among different ethnic groups with highest levels were demonstrated in the Caucasian/White population (46%). Majority (96%) of these subjects were receiving specific lifestyle advice from healthcare professionals due to metabolic conditions and comorbidities. However, most patients preferred diets that were rich in carbohydrates (65.8%) and only 43% subjects performed moderate exercise daily highlighting lack of understanding regarding MAFLD and lifestyle management.

CONCLUSION

There's a pressing need for increased awareness of MAFLD, especially in multiethnic high-risk groups. Additionally, the development of cost-effective strategies to stratify risk is essential to address this growing health concern.

Vitamin D Status and Longitudinal Changes in Body Composition in Patients with Chronic Obstructive Pulmonary Disease - A Prospective Observational Study

Background

Alterations in body weight and composition are common in patients with chronic obstructive pulmonary disease (COPD) and are independent predictors for morbidity and mortality. Low vitamin D status is also more prevalent in patients with COPD compared to controls and has been related to lower lung function, muscle atrophy and impaired musculoskeletal function. This study aimed to evaluate the association between vitamin D levels and status with body composition (BC), as well as with its changes over time.

Patients and Methods

Patients with COPD and controls without COPD, participating in the Individualized COPD Evaluation in relation to Ageing (ICE-Age) study, a prospective observational study, were included. Plasma 25-hydroxyvitamin D (25(OH)D) was measured at baseline and BC was measured by dual-energy X-ray absorptiometry scan, at baseline and after two years of follow-up. Multiple linear regression analyses were performed to assess the relationships between 25(OH)D (nmol/l) and longitudinal changes in BMI, fat-free mass index (FFMI), fat mas index (FMI) and bone mineral density (BMD).

Results

A total of 192 patients with COPD (57% males, mean ± SD age, 62 ± 7, FEV1, 49 ± 16% predicted) and 199 controls (45% males, mean ± SD age 61 ± 7) were included in this study. Vitamin D levels were significantly lower in patients with COPD (64 ± 26 nmol/L, 95% CI 60-68 nmol/L versus 75 ± 25 nmol/L, 95% CI 72-79 nmol/L) compared to controls. Both patients and controls presented a significant decline in FFMI and T-score hip, but vitamin D level or status did not determine differences in BC or changes in BC over time in either COPD or controls.

Conclusion

Vitamin D status was not associated with BC or longitudinal changes in BC. However, vitamin D insufficiency and low BMD were more prevalent in patients with COPD compared to controls.

Prevalence of vitamin D deficiency in South America: a systematic review and meta-analysis

CONTEXT

Vitamin D deficiency is considered a global public health issue, even in low-latitude countries where there is abundant sunlight radiation. Nevertheless, the prevalence of vitamin D insufficiency and deficiency in the South American continent has not been well characterized.

OBJECTIVE

The aim of this review was to estimate the prevalence of vitamin D deficiency (25-hydroxy-calciferol < 20 ng/mL) in South American populations.

DATA SOURCES

Seven electronic databases (MEDLINE, Web of Science, Embase, Biblioteca Virtual de Saúde, SciELO, Scopus, and Google Scholar) were searched systematically for observational studies published before July 1, 2021, and reporting vitamin D status of healthy adults in South America.

DATA EXTRACTION

Data were extracted using a standardized form. Risk of bias was assessed by the Joanna Briggs Institute Critical Appraisal Instrument for Studies Reporting Prevalence. All steps were conducted independently by two authors. Data were pooled using a random-effects model. Stratified meta-analysis and meta-regression were conducted (R software).

DATA ANALYSIS

Of 9460 articles identified, 96 studies with a total of 227 758 participants were included. The overall prevalence of vitamin D deficiency was 34.76% (79 studies; 95%CI, 29.68-40.21; I2 = 99%). There were significant differences in prevalence rates related to age, sex, country, latitude, season, and year of publication.

CONCLUSION

The prevalence of vitamin D deficiency is unexpectedly elevated in South American populations. Public health strategies should include efforts to prevent, detect, and treat vitamin D deficiency.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020169439.

Vitamin D and chronotype: is there any relationship in individuals with obesity?

PURPOSE

Chronotype is the attitude to perform most of the daily activities in the morning ("morning chronotype", MC) or in the evening ("evening chronotype", EC). The latter, as well as vitamin D deficiency, has been associated with an increased risk of obesity-related complications, likely through the promotion of insulin resistance. Therefore, we aimed to investigate whether there is any relationship between vitamin D (25-OH-D) and chronotype in individuals with obesity.

METHODS

In this cross-sectional study, we enrolled 59 individuals (43.1 ± 13 years; 17M/42F) with obesity. Anthropometric parameters, lifestyle habits, personal medical history, chronotype, insulin resistance, and 25-OH-D were assessed.

RESULTS

Individuals with EC presented significantly higher BMI than MC (p < 0.001), greater waist (p = 0.012), and hip circumferences (p = 0.001). Individuals with EC showed significantly lower insulin sensitivity (p = 0.017) and 25-OH-D than MC. In addition, the prevalence of vitamin D deficiency and impaired fasting glucose was significantly higher in EC than in MC. 25-OH-D directly correlated with chronotype score (r = 0.351; p = 0.019) whereas inversely with BMI (r = - 0.363; p = 0.016). The regression analysis showed that BMI was most tightly associated with 25-OH-D concentrations (β = - 0.323, p = 0.032), followed by chronotype score (β = 0.340, p = 0.042). Using chronotype score as the dependent variable, BMI significantly predicted a lower chronotype score (β = - 0.586, p < 0.001).

CONCLUSION

The present study showed that 25-OH-D, as well as chronotype, correlate independently with obesity.

Sex differences in vitamin D metabolism, serum levels and action

The ubiquity of vitamin D metabolising enzymes and vitamin D receptors in mammalian organisms suggests that vitamin D has pleiotropic effects. There are quite a few studies indicating the anticancer, cardioprotective and antidiabetic effects of vitamin D; however, the best-documented actions of vitamin D are the regulation of Ca-phosphate balance and its effect on immune function.Vitamin D levels in organisms are modulated by many environmental and non-environmental factors. One potential factor that may influence vitamin D levels and effects is the sex of the individuals studied. This review focuses on the scientific evidence indicating different synthesis and metabolism of vitamin D in females and males, mainly from PubMed database sources. The article verifies the sex differences in vitamin D levels reported around the world. Moreover, the different effects of vitamin D on the musculoskeletal, cardiovascular, nervous and immune systems, as well as cancer in males and females, were discussed.Most studies addressing sex differences in vitamin D levels and effects are observational studies with conflicting results. Therefore, carefully designed clinical trials and experiments on animal models should be carried out to determine the role of non-environmental factors that may differentiate vitamin D levels in females and males.

Leukocyte telomere length as a compensatory mechanism in vitamin D metabolism

Vitamin D deficiency is common among postmenopausal women. Telomere length can be a potential protective mechanism for age-related diseases. The objective of our study is to examine the association of vitamin D supplementation on leukocyte telomere length (LTL) in healthy postmenopausal women with vitamin D deficiency. The study was designed as a placebo-controlled study to investigate the short-term effects of vitamin D supplementation and seasonal changes on vitamin D related parameters, including 25(OH)D, 1,25(OH)2D parathormone (PTH), Vitamin D binding protein (VDBP), vitamin D receptor (VDR), and telomere length in a cohort of postmenopausal women (n = 102). The group was divided as supplementation (n = 52) and placebo groups (n = 50). All parameters were measured before and after treatment. Serum VDBP levels were measured by ELISA method and VDR, GC (VDBP) gene expressions and relative telomere lengths were measured in peripheral blood mononuclear cells (PBMC) using a quantitative real-time PCR method. The results demonstrate that baseline levels were similar between the groups. After vitamin D supplementation 25(OH)D, 1,25(OH)2D, PTH and VDBP levels were changed significantly compared to the placebo group. At the end of the study period, LTL levels were significantly increased in both groups and this change was more prominent in placebo group. The change in GC expression was significant between treatment and placebo groups but VDR expression remained unchanged. Even though the study was designed to solely assess the effects of vitamin D supplementation, LTL was significantly increased in the whole study group in summer months suggesting that LTL levels are affected by sun exposure and seasonal changes rather than supplementation. The study displayed the short-term effect of Vitamin D supplementation on vitamin D, PTH levels, LTL and vitamin D associated gene expressions. The relation between Vitamin D and LTL is not linear and could be confounded by several factors such as the population differences, regional and seasonal changes in sun exposure.

The role of vitamin D and vitamin D deficiency in orthopaedics and traumatology-a narrative overview of the literature

Vitamin D is considered to play an important role in musculoskeletal health. It’s classical function is the regulation of calcium and phosphate homeostasis, thus ensuring a balanced bone metabolism that is characterised by an equal amount of bone resorption and bone formation. In the past decades, a plethora of pre-clinical and clinical studies reporting on potential health-beneficial properties of vitamin D have emerged. Moreover, there is an abundance of reports highlighting vitamin D deficiency and insufficiency in patients with almost innumerable diseases. Further, it is estimated that more than one billion people globally are affected by insufficient vitamin D levels. As such, research on vitamin D has been particularly popular over the past years. In orthopaedics and traumatology, most studies describe favourable effects of vitamin D in general. However, the relative importance of vitamin D is oftentimes debated. In this narrative review of the literature, we consider first, the properties of vitamin D and how vitamin D, vitamin D deficiency and the vitamin D receptor (VDR) impact on musculoskeletal health. Secondly, we provide an overview of studies reporting the prevalence of vitamin D deficiency in traumatology and diverse orthopaedic diseases including bone oncology. Lastly, we emphasise recent findings and touch on future perspectives in vitamin D research.