Obesity and hypovitaminosis D: causality or casualty?

An Overview of Different Vitamin D Compounds in the Setting of Adiposity

A large body of research shows an association between higher body weight and low vitamin D status, as assessed using serum 25-hydroxyvitamin D concentrations. Vitamin D can be metabolised in adipose tissue and has been reported to influence gene expression and modulate inflammation and adipose tissue metabolism in vitro. However, the exact metabolism of vitamin D in adipose tissue is currently unknown. White adipose tissue expresses the vitamin D receptor and hydroxylase enzymes, substantially involved in vitamin D metabolism and efficacy. The distribution and concentrations of the generated vitamin D compounds in adipose tissue, however, are largely unknown. Closing this knowledge gap could help to understand whether the different vitamin D compounds have specific health effects in the setting of adiposity. This review summarises the current evidence for a role of vitamin D in adipose tissue and discusses options to accurately measure vitamin D compounds in adipose tissue using liquid chromatography tandem mass spectrometry (LC/MS-MS).

Management of the pediatric patient with asthma and obesity

Asthma and obesity are 2 of the most significant chronic diseases of childhood. Both are major public health problems that have been increasing in prevalence. Obesity increases the risk of developing asthma in children, and in children with asthma, obesity increases asthma severity and morbidity. The nature of this relationship is complex and not fully understood, but some pediatric patients with "obesity-related asthma" may represent a phenotype that differs from the more classical, atopic pediatric asthma. In this review, we investigate and discuss some of the currently available literature regarding treatment for asthma complicated by obesity in the pediatric population. We cover the importance of healthy lifestyle modifications, management of obesity-related comorbidities, and the potential role of nutritional supplementation or modification. We then review recent literature, mostly in adults, investigating the potential role of obesity or diabetes medications in the management of patients with asthma who have obesity. Finally, we discuss some of the necessary next steps before these potential new treatments can be considered as part of the standard clinical management of asthma.

Vitamin D status and its relationship with obesity indicators in Moroccan adult women

Background: Although vitamin D deficiency has been studied in various populations, there are few data on its prevalence and associated factors among Moroccan women. Aim: To determine the prevalence of vitamin D deficiency and investigate its association with body mass index (BMI), waist circumference, and serum concentrations of parathyroid hormone, calcium, and phosphorus in a sample of Moroccan adult women. Methods: This is a cross-sectional study conducted at Mohammed V Military Hospital of Instruction, Rabat. Anthropometric measurements and biochemical analyses were performed using standard procedures Results: A total of 714 women aged 18-65 years participated in this study. The overall prevalence of vitamin D deficiency was 74.4%. Approximately 24% and 51% of women had severe and moderate vitamin D deficiency, respectively. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were inversely correlated with BMI in vitamin D-deficient subjects (P = 0.036) and with parathyroid hormone 1-84 (PTH1-84) levels in the study sample (P = 0.010). PTH1-84 concentrations were greater among overweight/obese individuals compared to their non-overweight peers (P = 0.001) and tended to be higher among vitamin D-deficient women than vitamin D-sufficient women (P = 0.053). Conclusion: This study showed a very high prevalence of vitamin D deficiency in this sample of Moroccan women. Lower serum 25(OH)D levels were associated with increased BMI in vitamin D-deficient women and with elevated PTH1-84 levels among the study sample. Although these findings come from a convenience sample of women that attended a nutrition clinic, they underscore the urgent need to develop public health interventions to improve women's vitamin D status.

Vitamin D status and supplementation before and after Bariatric Surgery: Recommendations based on a systematic review and meta-analysis

Bariatric surgery is associated with a postoperative reduction of 25(OH) vitamin D levels (25(OH)D) and with skeletal complications. Currently, guidelines for 25(OH)D assessment and vitamin D supplementation in bariatric patients, pre- and post-surgery, are still lacking. The aim of this work is to analyse systematically the published experience on 25(OH)D status and vitamin D supplementation, pre- and post-surgery, and to propose, on this basis, recommendations for management. Preoperatively, 18 studies including 2,869 patients were evaluated. Prevalence of vitamin D insufficiency as defined by 25(OH)D < 30 ng/mL (75 nmol/L) was 85%, whereas when defined by 25(OH)D < 20 ng/mL (50 nmol/L) was 57%. The median preoperative 25(OH)D level was 19.75 ng/mL. After surgery, 39 studies including 5,296 patients were analysed and among those undergoing either malabsorptive or restrictive procedures, a lower rate of vitamin D insufficiency and higher 25(OH)D levels postoperatively were observed in patients treated with high-dose oral vitamin D supplementation, defined as ≥ 2,000 IU/daily (mostly D3-formulation), compared with low-doses (< 2,000 IU/daily). Our recommendations based on this systematic review and meta-analysis should help clinical practice in the assessment and management of vitamin D status before and after bariatric surgery. Assessment of vitamin D should be performed pre- and postoperatively in all patients undergoing bariatric surgery. Regardless of the type of procedure, high-dose supplementation is recommended in patients after bariatric surgery.

Vitamin D deficiency in adolescents with obesity - Altered metabolism or environmental factors?

Introduction

Introduction: obesity childhood is related to vitamin D deficiency. The aim of this study was to compare vitamin D status between adolescents with obesity living in an urban area and in a rural area. We hypothesized that environmental factors would be decisive in reducing the body content of vitamin D in patients with obesity. Methods: a cross-sectional clinical and analytical study (calcium, phosphorus, calcidiol and parathyroid hormone) was carried out in a group of 259 adolescents with obesity (BMI-SDS > 2.0), 249 adolescents with severe obesity (BMI-SDS > 3.0) and 251 healthy adolescents. The place of residence was categorized as urban or rural. Vitamin D status was defined according to the US Endocrine Society criteria. Results: vitamin D deficiency was significantly higher (p < 0.001) in severe obesity (55 %) and obesity groups (37.1 %) than in the control group (14 %). Vitamin D deficiency was more frequent in severe obesity (67.2 %) and obesity groups (51.2 %) living in urban areas than in those living in rural areas (41.5 % and 23.9 %, respectively). The patients with obesity living in urban residence did not present significant seasonal variations in vitamin D deficiency in contrast to those patients with obesity living in rural residence. Conclusions: the most probable mechanism for vitamin D deficiency in adolescents with obesity, rather than altered metabolic is the environmental factors (sedentary lifestyle and lack of adequate sunlight exposure).

The Sunlight-Vitamin D Connection: Implications for Patient Outcomes in the Surgical Intensive Care Unit

This review delves into the intricate relationship between Vitamin D and patient outcomes in the Surgical Intensive Care Unit (SICU). Vitamin D, known for its multifaceted roles in immune modulation, inflammation regulation, and maintenance of calcium homeostasis, emerges as a pivotal factor in the care of critically ill patients. Our exploration reveals a high prevalence of Vitamin D deficiency in the SICU, primarily attributable to limited sunlight exposure, comorbidities, and medication use. Importantly, Vitamin D status impacts infection rates, mortality, and length of stay in the SICU, making it a clinically relevant consideration. Mechanistic insights into the immunomodulatory and anti-inflammatory effects of Vitamin D shed light on its potential benefits in critical care. However, challenges, including accurate assessment, individualised supplementation, and ethical considerations regarding sunlight exposure, are evident. The prospect of personalised Vitamin D supplementation strategies offers promise for optimising patient care. In conclusion, the Sunlight-Vitamin D Connection holds significant potential to improve outcomes in the SICU, emphasising the importance of further research and tailored approaches for the well-being of critically ill individuals.

Optimizing vitamin D status in polycystic ovary syndrome: a systematic review and dose-response meta-analysis

CONTEXT

Polycystic ovary syndrome (PCOS) is a common and complex endocrine disorder in women of reproductive age. Vitamin D supplementation is a promising complementary therapy for PCOS, yet there is no consensus on an optimal dose, leading to a lack of evidence-based supplementation guidelines.

OBJECTIVE

The objective of this study was to conduct a vitamin D dose-response meta-analysis among women with PCOS.

DATA SOURCES

MEDLINE, CINAHL, and EMBASE databases from inception to November 2022 were searched for relevant articles.

DATA EXTRACTION

Study screening and bias assessment were conducted by 2 independent reviewers. Eight relevant studies were identified; data for serum 25(OH)D (nmol/L) at baseline and at 12 weeks in each intervention group (mean ± SD) and vitamin D dose were extracted.

DATA ANALYSIS

Estimates across studies were used to create a pooled curve, using restricted cubic splines with knots at the 10th, 50th, and 90th percentiles of the distribution of doses, to estimate the mean difference in effect for serum 25(OH)D at each dose compared with 0 IU/day. Sensitivity analyses were conducted fixing knots at 4000 IU/day and 7000 IU/day, which were a priori identified as potentially important thresholds, and to assess model fit and estimate heterogeneity. The pooled analysis demonstrated strong evidence of a dose-response relationship (P < .001), suggesting an increasing effect with increasing dose. An initial increase in serum 25(OH)D was evident until doses of approximately 3000 IU/day; this was followed by a plateau in effect between approximately 3000 IU/day and 5000 IU/day. The effect of supplementation with >5000 IU/day was unclear, given the minimal data at higher doses. The curve produced robust results for moderate doses (3000 IU/day to 4000 IU/day), which were not sensitive to model specification.

CONCLUSION

Women with PCOS are responsive to vitamin D supplementation, but the benefit of providing doses of >3000 IU/day appears minimal. Further data is required to determine dose-response at doses of >5000 IU/day, and whether higher intakes provide a clinically meaningful advantage in this population.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021259396.

IGF1 Genetic Polymorphism and the Association between Vitamin D Status and BMI Percentiles in Children

Both the IGF1 axis and hypovitaminosis D play a role in childhood obesity, either as a cause or a causality. While some studies suggest an interrelation between vitamin D status, IGF1, and obesity, this mechanism remains obscure. The aim of this study, therefore, was to explore associations between four genetic polymorphisms in the IGF1 axis in hypovitaminosis D-related obesity. The study included 116 pre-pubertal Israeli Arab children (52 girls), mean age 9.4 ± 2.6. Serum 25(OH)D was measured and anthropometric measures were obtained. Genomic DNA was extracted from peripheral EDTA-treated anti-coagulated blood using a standard protocol. Genotypes were determined using the Taqman allelic discrimination assay. The IGF genetic score was computed according to the additive genetic score model. A moderate-to-high negative correlation (r = 0.580, p < 0.05) was seen between the vitamin D status and body mass index (BMI) percentile of participants with high GS. Yet, no correlations were seen between vitamin D status and BMI percentile for participants with a low-to-moderate genetic score (GS) (GS ≤ 2). These results suggest that IGF1 genetic scores associated with elevated circulating IGF1 may indicate a tendency toward developing hypovitaminosis D-associated obesity.

Calcifediol in the management of vitamin D deficiency-related skeletal and extraskeletal diseases: overview and clinical cases

As well as being essential for musculoskeletal health, vitamin D is involved in numerous other physiological processes. Poor vitamin D status is linked to a wide range of diseases, including cardiovascular disease, autoimmune conditions, pulmonary disorders and upper respiratory tract infections. While optimal target concentrations of serum 25-hydroxyvitamin D (25(OH)D) for health maintenance or therapeutic purposes are still the subject of debate, there is reasonable agreement that serum 25(OH)D levels <50 nmol/L (20 ng/mL) constitute vitamin D deficiency and that severe deficiency states (serum 25(OH)D levels <25-30 nmol/L ≈ 10-12 ng/mL) should be avoided. Main strategies to maintain or improve vitamin D status are food supplementation and therapeutic use of medicinal forms of vitamin D. In this review, we examine evidence that implicates vitamin D deficiency in diverse conditions in the clinical settings of endocrinology, rheumatology, pneumology and reproductive health. Cholecalciferol (vitamin D3) is the most frequently used vitamin D supplement worldwide, though calcifediol (25-hydroxyvitamin D3) has recently become more widely available. Calcifediol is one step closer than cholecalciferol in the metabolic pathway to biologically active vitamin D. Pharmacokinetic differences between these vitamin D metabolites confer putative advantages for calcifediol in certain clinical situations. The clinical use of calcifediol is explored more closely through case studies, which illustrate its adjunctive role in the treatment of several vitamin D deficiency-related skeletal and extraskeletal diseases.

Effect of Vitamin D Deficiency on Voice: A Review of the Literature

OBJECTIVE

The purpose of this study is to review the current literature on the effect of hypovitaminosis D on voice.

STUDY DESIGN

Narrative review.

METHODS

The literature search from electronic databases included PubMed/MEDLINE, EMBASE, SCOPUS, and Google Scholar. Search terms included voice, voice quality, voice disorders, larynx, laryngology, acoustic analysis, vitamin D, calcitriol, cholecalciferol, vitamin D deficiency, and vitamin D insufficiency. All studies on patients with vitamin D deficiency, which included subjective and objective voice assessments, were reviewed.

RESULTS

A total of 39 studies were retrieved. Only four studies met the above-mentioned inclusion criteria and hence were included in this review. The total number of subjects analyzed was 466. The subjective voice outcome measures used were the Voice Handicap Index-10 (VHI-10), self-reported phonatory symptoms, and the GRBAS scale. Objective voice outcome measures included fundamental frequency, jitter, shimmer, noise-to-harmonic ratio, maximum phonation time, and dysphonia severity index.

CONCLUSION

Vitamin D deficiency has no significant effect on laryngeal muscles. There was no statistically significant difference in VHI-10 score, self-reported dysphonia, perceptual voice evaluation scores, or any of the acoustic measures between those with or without vitamin D deficiency.

Association between vitamin D deficiency and lipid profiles in overweight and obese adults: a systematic review and meta-analysis

OBJECTIVE

The association between vitamin D deficiency and lipid profiles in adults with overweight or obesity remains unclear and inconsistent. The aim of our study was to determine the relationship between lipid profiles and vitamin D deficiency in the overweight and obese adults.

METHODS

Four databases, including PubMed, the Web of Science, EMBASE and the Cochrane Library, were used to identify all studies on vitamin D status and lipid levels, including the serum levels of triglycerides (TGs), total cholesterol (TC), low-density lipoprotein cholesterol (LDL), and high-density lipoprotein cholesterol (HDL). The Weighted mean difference (WMD) with 95% confidence intervals (CIs) using random-effects models was used to assess the association between the lipid profile and vitamin D deficiency.

RESULTS

Twenty-one articles that included a total of 7952 adults with overweight or obesity (BMI ≥ 25 kg/m2) were included. The overall results revealed that compared with the controls, individuals with vitamin D deficiency showed higher levels of TG (WMD = 15.01; 95%CI, 2.51-27.52) and TC (WMD = 8.61; 95%CI, 1.31-15.92). Moreover, vitamin D deficiency was related to an increased level of LDL (WMD = 6.12; 95%CI, 0.02-12.23). HDL level was inversely associated with the vitamin D deficiency status (WMD = -2.57; 95%CI, -4.26, -0.88).

CONCLUSIONS

Among the adults with overweight or obesity, the vitamin D deficient group displayed impaired lipid profiles, including increased TG, TC and LDL levels and reduced HDL level.

Maternal vitamin D status and risk of childhood overweight at 5 years of age in two Nordic cohort studies

Introduction

Maternal vitamin D status during pregnancy has been suggested to have a role in childhood adiposity development, but results are conflicting. Our aims were to investigate [1] the relationships between maternal 25-hydroxyvitamin D (25OHD) during pregnancy and the child's body mass index (BMI) and risk of overweight at 5 years of age, and [2] maternal pre-pregnancy BMI as effect modifier for these associations.

Methods

Data sources included a subsample from the Norwegian Mother, Father and Child Cohort Study (MoBa sub-cohort; N = 2,744) and the Swedish GraviD cohort study (N = 891). Maternal 25OHD was analyzed in gestational week 18 in the MoBa sub-cohort and week 10 in the GraviD cohort. In the MoBa sub-cohort, parents reported their child's documented measures of weight and length or height from the health card at routine check-up. In the GraviD cohort, this information was collected directly from medical records. Childhood overweight (including obesity) was identified using the International Obesity Task Force cut-offs. Linear and logistic regression models were used to investigate the association between maternal 25OHD and child's BMI and risk of overweight at 5 years of age in each cohort separately, and in a pooled dataset.

Results

In the pooled analysis, maternal 25OHD <30 nmol/L was associated with lower BMI in children at 5 years of age, but not with risk of overweight. Interaction analysis showed that the association was predominant among children of mothers with pre-pregnancy BMI ≥25 kg/m2.

Conclusion

Low maternal vitamin D status, particularly in mothers with overweight or obesity, predicted lower BMI in their five-year-old children. However, there was no evidence of an effect on overweight in these children.

The Mutual Interplay between Bone, Glucose and Lipid Metabolism: The Role of Vitamin D and PTH

BACKGROUND

We sought to investigate the mutual interplay between bone, glucose and lipid metabolism in a wide cohort of community-based subjects.

METHODS

We studied 1240 blood donors (F/M ratio 1/3.2, mean age 41.9 ± 11.7 SD). Serum ionized (Ca⁺⁺), magnesium (Mg⁺⁺), 25-hydroxy-vitamin D [25(OH)D], PTH-1-84, 1,25-dihydroxyvitamin D [1,25(OH)₂D], total cholesterol (C), HDL-C, triglycerides and glucose were measured and LDL-C levels were calculated in all subjects.

RESULTS

25(OH)D negatively correlated with BMI (R = -0.11), PTH (R = -0.16) (p < 0.0001), total C (R = -0.06, p < 0.05) and triglycerides (R = -0.13, p < 0.0001) and positively with 1,25(OH)₂D (R = 0.12) and creatinine (R = 0.17) (p < 0.0001). Serum PTH positively correlated with total C (R = 0.08, p < 0.01), LDL-C (R = 0.1, p < 0.001), triglycerides (R = 0.09, p < 0.01) and glucose (R = 0.15, p < 0.0001) and negatively with HDL-C (R = -0.09, p < 0.01). The odds of showing abnormal serum triglycerides and HDL-C increased as 25(OH)D decreased (p < 0.0001 and p < 0.03) and PTH increased (p < 0.03 and p = 0.05), while the odds of showing abnormal LDL-C levels increased in association with elevated PTH (p < 0.01).

CONCLUSION

Vitamin D, PTH, glucose and lipid metabolism are mutually influenced. Hypovitaminosis D predisposes toward worsening lipid profiles through the actions of PTH, while serum PTH levels per se associate with higher glucose and LDL-C levels.

Vitamin D intake and determinants of vitamin D status during pregnancy in The Norwegian Mother, Father and Child Cohort Study

Background

Norwegian data on vitamin D status among pregnant women indicate a moderate to high prevalence of insufficient vitamin D status (25-hydroxyvitamin D (25OHD) concentrations ≤50  nmol/L). There is a lack of population-based research on vitamin D intake and determinants of 25OHD in pregnant women from northern latitudes. The aims of this study were (1) to evaluate total vitamin D intake from both diet and supplements, (2) to investigate determinants of vitamin D status, and (3) to investigate the predicted response in vitamin D status by total vitamin D intake, in pregnant Norwegian women.

Methods

In total, 2,960 pregnant women from The Norwegian Environmental Biobank, a sub-study within The Norwegian Mother, Father and Child Cohort Study (MoBa), were included. Total vitamin D intake was estimated from a food frequency questionnaire in gestational week 22. Concentrations of plasma 25OHD was analyzed by automated chemiluminescent microparticle immunoassay method in gestational week 18. Candidate determinant variables of 25OHD were chosen using stepwise backward selection and investigated using multivariable linear regression. Predicted 25OHD by total vitamin D intake, overall and stratified by season and pre-pregnancy BMI, was explored using restricted cubic splines in an adjusted linear regression.

Results

Overall, about 61% of the women had a total vitamin D intake below the recommended intake. The main contributors to total vitamin D intake were vitamin D supplements, fish, and fortified margarine. Higher 25OHD concentrations were associated with (in descending order of the beta estimates) summer season, use of solarium, higher vitamin D intake from supplements, origin from high income country, lower pre-pregnancy BMI, higher age, higher vitamin D intake from foods, no smoking during pregnancy, higher education and energy intake. During October-May, a vitamin D intake according to the recommended intake was predicted to reach sufficient 25OHD concentrations >50  nmoL/L.

Conclusion

The findings from this study highlight the importance of the vitamin D intake, as one of few modifiable determinants, to reach sufficient 25OHD concentrations during months when dermal synthesis of vitamin D is absent.

Vitamin D in atherosclerosis and cardiovascular events

Both experimental and clinical findings linking vitamin D to cardiovascular (CV) risk have prompted consideration of its supplementation to improve overall health. Yet several meta-analyses do not provide support for the clinical effectiveness of this strategy. Meanwhile, the understanding of the roles of vitamin D in the pathophysiology of CV diseases has evolved. Specifically, recent work has revealed some non-classical pleiotropic effects of vitamin D, increasing the complexity of vitamin D signalling. Within particular microenvironments (e.g. dysfunctional adipose tissue and atherosclerotic plaque), vitamin D can act locally at cellular level through intracrine/autocrine/paracrine feedforward and feedback circuits. Within atherosclerotic tissues, 'local' vitamin D levels may influence relevant systemic consequences independently of its circulating pool. Moreover, vitamin D links closely to other signalling pathways of CV relevance including those driving cellular senescence, ageing, and age-related diseases-among them CV conditions. This review updates knowledge on vitamin D biology aiming to clarify the widening gap between experimental and clinical evidence. It highlights the potential reverse causation confounding correlation between vitamin D status and CV health, and the need to consider novel pathophysiological concepts in the design of future clinical trials that explore the effects of vitamin D on atherosclerosis and risk of CV events.

Vitamin D and malabsorptive gastrointestinal conditions: A bidirectional relationship?

This paper is one of the outcomes of the 5th International Conference "Controversies in Vitamin D" held in Stresa, Italy from 15 to 18 September 2021 as part of a series of annual meetings which was started in 2017. The scope of these meetings is to discuss controversial issues about vitamin D. Publication of the outcomes of the meeting in international journals allows a wide sharing of the most recent data with the medical and academic community. Vitamin D and malabsorptive gastrointestinal conditions was one of the topics discussed at the meeting and focus of this paper. Participants to the meeting were invited to review available literature on selected issues related to vitamin D and gastrointestinal system and to present their topic to all participants with the aim to initiate a discussion on the main outcomes of which are reported in this document. The presentations were focused on the possible bidirectional relationship between vitamin D and gastrointestinal malabsorptive conditions such as celiac disease, inflammatory bowel diseases (IBDs) and bariatric surgery. In fact, on one hand the impact of these conditions on vitamin D status was examined and on the other hand the possible role of hypovitaminosis D on pathophysiology and clinical course of these conditions was also evaluated. All examined malabsorptive conditions severely impair vitamin D status. Since vitamin D has known positive effects on bone this in turn may contribute to negative skeletal outcomes including reduced bone mineral density, and increased risk of fracture which may be mitigated by vitamin D supplementation. Due to the immune and metabolic extra-skeletal effects there is the possibility that low levels of vitamin D may negatively impact on the underlying gastrointestinal conditions worsening its clinical course or counteracting the effect of treatment. Therefore, vitamin D status assessment and supplementation should be routinely considered in all patients affected by these conditions. This concept is strengthened by the existence of a possible bidirectional relationship through which poor vitamin D status may negatively impact on clinical course of underlying disease. Sufficient elements are available to estimate the desired threshold vitamin D level above which a favourable impact on the skeleton in these conditions may be obtained. On the other hand, ad hoc controlled clinical trials are needed to better define this threshold for obtaining a positive effect of vitamin D supplementation on occurrence and clinical course of malabsorptive gastrointestinal diseases.

Calcifediol: a review of its pharmacological characteristics and clinical use in correcting vitamin D deficiency

BACKGROUND

In addition to the role of vitamin D in bone mineralization, calcium and phosphate homeostasis, and skeletal health, evidence suggests an association between vitamin D deficiency and a wide range of chronic conditions. This is of clinical concern given the substantial global prevalence of vitamin D deficiency. Vitamin D deficiency has traditionally been treated with vitamin D₃ (cholecalciferol) or vitamin D₂ (ergocalciferol). Calcifediol (25-hydroxyvitamin D₃) has recently become available more widely.

METHODS

By means of targeted literature searches of PubMed, this narrative review overviews the physiological functions and metabolic pathways of vitamin D, examines the differences between calcifediol and vitamin D₃, and highlights clinical trials conducted with calcifediol in patients with bone disease or other conditions.

RESULTS

For supplemental use in the healthy population, calcifediol can be used at doses of up to 10 µg per day for children ≥ 11 years and adults and up to 5 µg/day in children 3-10 years. For therapeutic use of calcifediol under medical supervision, the dose, frequency and duration of treatment is determined according to serum 25(OH)D concentrations, condition, type of patient and comorbidities. Calcifediol differs pharmacokinetically from vitamin D₃ in several ways. It is independent of hepatic 25-hydroxylation and thus is one step closer in the metabolic pathway to active vitamin D. At comparable doses to vitamin D₃, calcifediol achieves target serum 25(OH)D concentrations more rapidly and in contrast to vitamin D₃, it has a predictable and linear dose-response curve irrespective of baseline serum 25(OH)D concentrations. The intestinal absorption of calcifediol is relatively preserved in patients with fat malabsorption and it is more hydrophilic than vitamin D₃ and thus is less prone to sequestration in adipose tissue.

CONCLUSION

Calcifediol is suitable for use in all patients with vitamin D deficiency and may be preferable to vitamin D₃ for patients with obesity, liver disease, malabsorption and those who require a rapid increase in 25(OH)D concentrations.

Gluten-Free Diet and Metabolic Syndrome: Could Be a Not Benevolent Encounter?

Celiac disease is a rising disorder and is becoming frequently diagnosed in recent years. To date, the only available treatment is the gluten-free diet (GFD). The role of gluten on components of metabolic syndrome and on related inflammatory response is still unclear due to controversial results. In recent years, scientific focus on this topic has been growing up, in particular regarding the role of the GFD on glycometabolic parameters and diabetes. In addition, studies on the remaining components showed discordant results, which was likely due to heterogeneous and large celiac disease populations and to the lack of prospective studies. Furthermore, knowledge about the role of the GFD on inflammatory cytokines and the relationship among vitamin D and celiac disease, metabolic syndrome (MS) and GFD is needed. In this narrative review, we provided evidence regarding the role of the GFD on glycometabolic parameters, cholesterol, triglycerides, waist circumference, blood pressure and inflammatory cascade, also evaluating the role of vitamin D, trying to summarize whether this nutritional pattern may be a value-added for subjects with dysmetabolic conditions. Finally, due to the limited findings and very low-certainty evidence, predominantly based on observational studies, the real effects of a GFD on different components of MS, however, are unclear; nevertheless, an improvement in HDL levels has been reported, although data on glycemic levels are discordant.

Vitamin D insufficiency and its association with adipokines and atherogenic indices in patients with metabolic syndrome: A case-control study

INTRODUCTION

Vitamin D deficiency is one of the most common nutritional disorders in most countries of the world. The present study was designed and implemented with the aim of investigating the relationship between vitamin D deficiency and the level of adipokines, atherogenesis indicators and factors related to metabolic syndrome.

METHODS

This case-control study was done on 195 patients with metabolic syndrome aged 20-50 y who attended the health centers in Zabol County, northeast Iran, between April 2021 and January 2022. Anthropometric and biochemical parameters were measured for all subjects with standard methods. To determine serum 25(OH)D levels, we used enzymatic linked immunosorbent assay (ELISA) kits. Atherogenic index of plasma (AIP) was calculated as log (TG/HDL-c). The visceral adiposity index (VAI) and the lipid accumulation product (LAP) were estimated according to standard formulas.

RESULTS AND DISCUSSION

Participants in the case group had lower serum levels of 25(OH)D compared to controls (19.8 ± 6.2 ng/ml vs. 41.2 ± 9.7ng/ml, P<0.001). We found that the mean serum levels of fasting blood sugar (P=0.023) and TG (P=0.008) as well as HOMA-IR (P=0.023) were significantly higher in the cases compared to controls. Also, patients with MetS and vitamin D insufficiency (cases) had higher AIP (P=0.040) and LAP (P=0.012) than controls. Furthermore, serum 25(OH)D levels showed significant inverse correlations with serum RBP-4 and a positive correlation with serum omentin-1 concentrations. The results of the present study showed that vitamin D deficiency correlated with some of the cardiometabolic risk factors among the patients with MetS.

Pediatric obesity-Long-term consequences and effect of weight loss

Childhood obesity is, according to the WHO, one of the most serious challenges of the 21st century. More than 100 million children have obesity today. Already during childhood, almost all organs are at risk of being affected by obesity. In this review, we present the current knowledge about diseases associated with childhood obesity and how they are affected by weight loss. One major causative factor is obesity-induced low-grade chronic inflammation, which can be observed already in preschool children. This inflammation-together with endocrine, paracrine, and metabolic effects of obesity-increases the long-term risk for several severe diseases. Type 2 diabetes is increasingly prevalent in adolescents and young adults who have had obesity during childhood. When it is diagnosed in young individuals, the morbidity and mortality rate is higher than when it occurs later in life, and more dangerous than type 1 diabetes. Childhood obesity also increases the risk for several autoimmune diseases such as multiple sclerosis, Crohn's disease, arthritis, and type 1 diabetes and it is well established that childhood obesity also increases the risk for cardiovascular disease. Consequently, childhood obesity increases the risk for premature mortality, and the mortality rate is three times higher already before 30 years of age compared with the normal population. The risks associated with childhood obesity are modified by weight loss. However, the risk reduction is affected by the age at which weight loss occurs. In general, early weight loss-that is, before puberty-is more beneficial, but there are marked disease-specific differences.

Vitamin D status modulates mitochondrial oxidative capacities in skeletal muscle: role in sarcopenia

Skeletal muscle mitochondrial function is the biggest component of whole-body energy output. Mitochondrial energy production during exercise is impaired in vitamin D-deficient subjects. In cultured myotubes, loss of vitamin D receptor (VDR) function decreases mitochondrial respiration rate and ATP production from oxidative phosphorylation. We aimed to examine the effects of vitamin D deficiency and supplementation on whole-body energy expenditure and muscle mitochondrial function in old rats, old mice, and human subjects. To gain further insight into the mechanisms involved, we used C2C12 and human muscle cells and transgenic mice with muscle-specific VDR tamoxifen-inducible deficiency. We observed that in vivo and in vitro vitamin D fluctuations changed mitochondrial biogenesis and oxidative activity in skeletal muscle. Vitamin D supplementation initiated in older people improved muscle mass and strength. We hypothesize that vitamin D supplementation is likely to help prevent not only sarcopenia but also sarcopenic obesity in vitamin D-deficient subjects.

Vitamin D Status and Potential Therapeutic Options in Critically Ill Patients: A Narrative Review of the Clinical Evidence

Vitamin D covers roles of paramount importance in the regulation of multiple physiological pathways of the organism. The metabolism of vitamin D involves kidney-liver crosstalk and requires an adequate function of these organs, where vitamin D is progressively turned into active forms. Vitamin D deficiency has been widely reported in patients living in the community, being prevalent among the most vulnerable subjects. It has been also documented in many critically ill patients upon admission to the intensive care unit. In this context, vitamin D deficiency may represent a risk factor for the development of life-threatening clinical conditions (e.g., infection and sepsis) and worse clinical outcomes. Several researchers have investigated the impact of vitamin D supplementation showing its feasibility, safety, and effectiveness, although conflicting results have put into question its real benefit in critically ill patients. The existing studies included heterogeneous critically ill populations and used slightly different protocols of vitamin D supplementation. For these reasons, pooling up the results is difficult and not conclusive. In this narrative review, we described vitamin D physiology and the pathophysiology of vitamin D depletion with a specific focus on critically ill patients with liver dysfunction, acute kidney injury, acute respiratory failure, and sepsis.

Changes in Metabolic Parameters in Patients with Diabetic Kidney Disease Depending on the Status of D3

BACKGROUND

Type 2 diabetes is a metabolic disease characterized by hyperglycemia as a result of insulin resistance and decreased insulin secretion. A relatively large number of patients with this type of diabetes have abdominal obesity, which also affects insulin resistance development. Chronic hyperglycemia can lead to damage and dysfunction of various organs, and a striking example is diabetic nephropathy. Diabetic nephropathy is a specific kind of kidney damage that occurs due to complications of diabetes and is accompanied by the formation of diffuse or nodular glomerulosclerosis, which can lead to terminal renal failure and requires immediate substitution through renal therapy or renal transplantation. Diabetic nephropathy is diagnosed with albuminuria and a decrease in the rate of glomerular filtration.

METHODS

This review was based on a literature search for the most important evidence of vitamin D as a possible method of prevention for obesity, type 2 diabetes, and diabetic nephropathy. Collected published articles were summarized according to their overall themes.

RESULTS

In this review, we considered vitamin D as a possible method of treatment for type 2 diabetes, as well as its complications, including diabetic nephropathy.

CONCLUSION

Studies show that vitamin D inhibits the renin-angiotensin-aldosterone system, resulting in improved renal function in diabetic nephropathy. Vitamin D also has antiinflammatory, antiproliferative, and anti-metastatic effects, which improve endothelial function.

Analysis of Bone Histomorphometry in Rat and Guinea Pig Animal Models Subject to Hypoxia

Hypoxia may be associated with alterations in bone remodeling, but the published results are contradictory. The aim of this study was to characterize the bone morphometry changes subject to hypoxia for a better understanding of the bone response to hypoxia and its possible clinical consequences on the bone metabolism. This study analyzed the bone morphometry parameters by micro-computed tomography (μCT) in rat and guinea pig normobaric hypoxia models. Adult male and female Wistar rats were exposed to chronic hypoxia for 7 and 15 days. Additionally, adult male guinea pigs were exposed to chronic hypoxia for 15 days. The results showed that rats exposed to chronic constant and intermittent hypoxic conditions had a worse trabecular and cortical bone health than control rats (under a normoxic condition). Rats under chronic constant hypoxia were associated with a more deteriorated cortical tibia thickness, trabecular femur and tibia bone volume over the total volume (BV/TV), tibia trabecular number (Tb.N), and trabecular femur and tibia bone mineral density (BMD). In the case of chronic intermittent hypoxia, rats subjected to intermittent hypoxia had a lower cortical femur tissue mineral density (TMD), lower trabecular tibia BV/TV, and lower trabecular thickness (Tb.Th) of the tibia and lower tibia Tb.N. The results also showed that obese rats under a hypoxic condition had worse values for the femur and tibia BV/TV, tibia trabecular separation (Tb.Sp), femur and tibia Tb.N, and BMD for the femur and tibia than normoweight rats under a hypoxic condition. In conclusion, hypoxia and obesity may modify bone remodeling, and thus bone microarchitecture, and they might lead to reductions in the bone strength and therefore increase the risk of fragility fracture.

High Prevalence of Hypovitaminosis D in Adolescents Attending a Reference Centre for the Treatment of Obesity in Switzerland

Background: Hypovitaminosis D is common in populations with obesity. This study aimed at assessing (1) the prevalence of hypovitaminosis D and (2) the associations between vitamin D levels and cardiovascular risk factors in adolescents attending a reference centre for the treatment of obesity. Design: Cross-sectional pilot study conducted in the paediatric obesity unit of the Lausanne university hospital, Switzerland. Methods: Participants were considered eligible if they (1) were aged between 10 to 16.9 years and (2) consulted between 2017 and 2021. Participants were excluded if (1) they lacked vitamin D measurements or (2) the vitamin D measurement was performed one month after the base anthropometric assessment. Hypovitaminosis D was considered if the vitamin D level was <30 ng/mL (<75 nmol/L). Severe obesity was defined as a BMI z-score > 3 SD. Results: We included 52 adolescents (31% girls, mean age 13 ± 2 years, 33% with severe obesity). The prevalence of hypovitaminosis D was 87.5% in girls and 88.9% in boys. The vitamin D levels were inversely associated with BMI, Spearman r and 95% CI: −0.286 (−0.555; −0.017), p = 0.037; they were not associated with the BMI z-score: −0.052 (−0.327; 0.224), p = 0.713. The vitamin D levels were negatively associated with the parathormone levels (−0.353 (−0.667; −0.039), p = 0.028) and positively associated with the calcium levels (0.385 (0.061; 0.708), p = 0.020), while no association was found between vitamin D levels and blood pressure and lipid or glucose levels. Conclusion: almost 9 out of 10 adolescents with obesity in our cohort presented with hypovitaminosis D. Hypovitaminosis D does not seem to be associated with a higher cardiovascular risk profile in this group.

Association between anthropometric markers of adiposity, adipokines and vitamin D levels

Inverse association between serum levels of vitamin D and obesity has been pointed out in several studies. Our aim was to identify to the associations between vitamin D levels and a large panel of anthropometric markers and adipokines. Cross-sectional study including 6485 participants. Anthropometric markers included body mass index (BMI), % body fat, waist, waist-to-hip (WHR), waist-to-height (WHtR), conicity index, body roundness index (BRI) and a body shape index (ABSI). 55.7% of women and 60.1% of men presented with vitamin D deficiency. Vitamin D levels were negatively associated with most anthropometric markers, with correlation coefficients ranging between −0.017 (ABSI) and −0.192 (BMI) in women and between −0.026 (weight) and −0.130 (% body fat) in men. Vitamin D levels were inversely associated with leptin levels in both sexes and positively associated with adiponectin levels in women only. The likelihood of vitamin D deficiency increased with increasing adiposity levels, except for ABSI (women) and BMI (men). Total body fat, rather than localized or unevenly distributed body fat, is the adiposity marker most associated with decreased vitamin D levels. Monitoring vitamin D levels in people with overweight/obesity is essential.

Vitamin D insufficiency, excessive weight gain, and insulin resistance during pregnancy

BACKGROUND AND AIMS

Vitamin D insufficiency has been related to metabolic complications during pregnancy, including insulin resistance. There is evidence that excessive weight gain can negatively influence 25-hydroxyvitamin D (25(OH)D) concentrations. We aimed to investigate the association of vitamin D insufficiency during pregnancy (25(OH)D₃ < 75 nmol/L in the second and third trimesters) with insulin resistance, and explore whether excessive gestational weight gain (GWG) could modify such relationship.

METHODS AND RESULTS

A prospective longitudinal analysis was conducted within the MINA-Brazil Study among 444 pregnant women enrolled in antenatal care and with complete data on 25(OH)D₃, weight gain, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR). Quantile and logistic regression models were conducted with adjustment for sociodemographic, obstetric, and lifestyle characteristics, as well as gestational age and seasonality at outcome assessment. Predicted probabilities for insulin resistance (HOMA-IR>2.71) were estimated according to excessive GWG. Persistent vitamin D insufficiency was associated with increasing insulin concentrations (p for trend = 0.04); pregnant women with vitamin D insufficiency in the second or third trimester had an odds ratio of 1.83 (95% confidence interval (95% CI) = 1.03, 3.27) for insulin resistance, with significant modification by GWG (p = 0.038). Among participants without excessive GWG, the predicted probability for insulin resistance was 0.345 (95% CI = 0.224, 0.467) for those with persistent vitamin D insufficiency, and 0.134 (95% CI = 0.046, 0.221) for those who were sufficient in vitamin D. Probabilities for insulin resistance did not vary according to vitamin D status among participants with excessive GWG.

CONCLUSION

Vitamin D insufficiency was associated with insulin resistance in the third trimester of pregnancy, dependent on excessive GWG.

No Association between Vitamin D and Weight Gain: A Prospective, Population-Based Study

Background: The association between vitamin D and weight gain remains controversial due to important limitations in the studies. We investigated the relationship between vitamin D levels and 5 and 10 years of weight and waist circumference change in a population-based prospective cohort study. Methods: Prospective study including participants aged between 35 and 75 years living in the city of Lausanne, Switzerland. Weight and waist change at 5- and 10-year follow-up were assessed according to baseline vitamin D status (normal, insufficiency and deficiency). Results: A total of 3638 participants (47.9 % women, mean age 51.6 ± 10.4 years) were included for the 5-year follow-up. No association was found between vitamin D categories and weight change, multivariate-adjusted average ± standard error: 1.6 ± 0.3, 1.5 ± 0.2 and 1.2 ± 0.1 kg for normal, insufficiency and deficiency, respectively, p = 0.159. For waist change, the corresponding values were 3.3 ± 0.4, 3.3 ± 0.2 and 3.4 ± 0.2 cm, p = 0.792. For the 10-year follow-up, data from 2999 participants (45.8% women, mean age 50.8 ± 10.3 years) were used. No association was found for weight 2.3 ± 0.4, 2.3 ± 0.2 and 2.0 ± 0.2 kg, p = 0.588, or for waist 3.7 ± 0.4, 3.6 ± 0.3 and 4.2 ± 0.2 cm for normal, insufficiency and deficiency, respectively, p = 0.259. Conclusion: No association between vitamin D status and weight or waist gain at 5- and 10-year follow-up was found.

Factors associated with trabecular bone score in postmenopausal women with type 2 diabetes and normal bone mineral density

BACKGROUND

Osteoporosis and type 2 diabetes (T2D) have been recognized as a widespread comorbidity leading to excess mortality and an enormous healthcare burden. In T2D, bone mineral density (BMD) may underestimate the risk of low-energy fractures as bone quality is reduced. It was hypothesized that a decrease in the trabecular bone score (TBS), a parameter assessing bone microarchitecture, may be an early marker of impaired bone health in women with T2D.

AIM

To identify clinical and body composition parameters that affect TBS in postmenopausal women with T2D and normal BMD.

METHODS

A non-interventional cross-sectional comparative study was conducted. Potentially eligible subjects were screened at tertiary referral center. Postmenopausal women with T2D, aged 50-75 years, with no established risk factors for secondary osteoporosis, were included. BMD, TBS and body composition parameters were assessed by dual-energy X-ray absorptiometry. In women with normal BMD, a wide range of anthropometric, general and diabetes-related clinical and laboratory parameters were evaluated as risk factors for TBS decrease using univariate and multivariate regression analysis and analysis of receiver operating characteristic (ROC) curves.

RESULTS

Three hundred twelve women were initially screened, 176 of them met the inclusion criteria and underwent dual X-ray absorptiometry. Those with reduced BMD were subsequently excluded; 96 women with normal BMD were included in final analysis. Among them, 43 women (44.8%) showed decreased TBS values (≤ 1.31). Women with TBS ≤ 1.31 were taller and had a lower body mass index (BMI) when compared to those with normal TBS (Р = 0.008 and P = 0.007 respectively). No significant differences in HbA1c, renal function, calcium, phosphorus, alkaline phosphatase, PTH and 25(ОН)D levels were found. In a model of multivariate linear regression analysis, TBS was positively associated with gynoid fat mass, whereas the height and androgen fat mass were associated negatively (all P < 0.001). In a multiple logistic regression, TBS ≤ 1.31 was associated with lower gynoid fat mass (adjusted odd ratio [OR], 0.9, 95% confidence interval [CI], 0.85-0.94, P < 0.001), higher android fat mass (adjusted OR, 1.13, 95%CI, 1.03-1.24, P = 0.008) and height (adjusted OR, 1.13, 95%CI, 1.05-1.20, P < 0.001). In ROC-curve analysis, height ≥ 162.5 cm (P = 0.04), body mass index ≤ 33.85 kg/m² (P = 0.002), gynoid fat mass ≤ 5.41 kg (P = 0.03) and android/gynoid fat mass ratio ≥ 1.145 (P < 0.001) were identified as the risk factors for TBS reduction.

CONCLUSION

In postmenopausal women with T2D and normal BMD, greater height and central adiposity are associated with impaired bone microarchitecture.

Bone loss induced by cancer treatments in breast and prostate cancer patients

Cancer and cancer therapies are a major factor risk for osteoporosis due to bone loss and deterioration of bone microarchitecture. Both factors contribute to a decrease in bone strength and, consequently, increased bone fragility and risk of fracture. Cancer-associated bone loss is a multifactorial process, and optimal interdisciplinary management of skeletal health, accurate assessment of bone density, and early diagnosis are essential when making decisions aimed at reducing bone loss and fracture risk in patients who have received or are receiving treatment for cancer. In this document, a multidisciplinary group of experts collected the latest evidence on the pathophysiology of osteoporosis and its prevention, diagnosis, and treatment with the support of the Spanish scientific society SEOM. The aim was to provide an up-to-date and in-depth view of osteoporotic risk and its consequences, and to present a series of recommendations aimed at optimizing the management of bone health in the context of cancer.

Vitamin D is associated with body composition and fat intake, but not with cardiometabolic parameters in adults with obesity

Adults with obesity are at higher risk for developing hypovitaminosis D. Some studies suggest that reduced levels of serum 25-hydroxyvitamin D (25(OH)D) may also be related to disorders in cardiometabolic parameters. However, because of the association between 25(OH)D and obesity, we hypothesized that body composition can be a confounding factor in the association of 25(OH)D with cardiometabolic parameters, and that 25(OH)D is inversely associated with body composition and cardiometabolic parameters and directly associated with fat intake. The aim of this study was to analyze the associations between 25(OH)D with body composition, fat intake, and cardiometabolic parameters in adults with obesity. This cross-sectional study consisted of 52 adults with obesity (61.53% female; 37.50 ± 6.88 years; body mass index [BMI]: 33.60 ± 2.89 kg/m²). Cardiometabolic parameters (fasting blood glucose, insulin resistance index, C-reactive protein, blood pressure, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and cholesterol), body mass, BMI, waist circumference, body fat percentage, and fat intake were evaluated. Body mass was negatively associated with 25(OH)D (β = -0.108; P = .048; and R² = 0.090) and BMI (β = -0.621; P = .031; and R² = 0.103), both adjusted for fat intake. 25(OH)D was positively associated with fat intake (β = 0.129; P = .045 and R² = 0.078) adjusted for sex, age, and skin color. Cardiometabolic parameters were not associated with 25(OH)D, even after adjusted by body composition variables. However, the high prevalence of hypovitaminosis D (75%) and the negative association between 25(OH)D and body composition reinforce the importance of analyzing and monitoring vitamin D status in this population.

Different Vitamin D Supplementation Strategies in the First Years of Life: A Systematic Review

Vitamin D (VD) is an essential micronutrient with multiple functions for human growth, and adequate intake should be guaranteed throughout life. However, VD insufficiency is observed in infants all over the world. Low VD concentration in the breast milk of non-supplemented mothers and low compliance to VD daily supplementation are the main causes of VD insufficiency, especially in the long term. Furthermore, VD supplementation dosages are still debated and differ by country. We conducted a systematic review to compare the most recent evidence on different postnatal VD supplementation strategies, determining whether supplementation given to the mother is as effective as that administered directly to the child, and whether different dosages and administration schedules differ significantly in terms of efficacy and safety. We identified 18 randomized controlled trials (RCTs) addressing the role of infant (n = 961), maternal (n = 652) or combined infant and maternal VD supplementation (n = 260 pairs). In all studies, similar outcomes emerged in terms of efficacy and safety. According to our findings, alternative approaches of VD supplementation may be adopted, especially in cases where the adherence to daily supplementation strategies is poor. This review shows that different dosages and supplementation strategies result in similar VD sufficiency rates. Therefore, international guidelines may be revised in the future to offer multiple and different options of supplementation for specific settings and ages.

Vitamin D in Osteosarcopenic Obesity

Osteosarcopenic obesity is a unique clinical condition where low bone and muscle mass coexist in individuals with obesity. Alterations in adipose tissue, skeletal muscle and bone are strictly interconnected, and vitamin D plays key roles in several metabolic pathways that are involved in maintaining musculoskeletal health and glucose homeostasis. We reviewed the available literature on mechanisms underlying osteosarcopenic obesity, with a focus on the role of vitamin D in the pathogenesis and treatment of the condition. We found that, although evidence from large observational studies and pre-clinical experiments strongly supports a role of vitamin D deficiency in the pathogenesis of osteosarcopenic obesity, the common belief that vitamin D improves musculoskeletal health lacks solid clinical evidence, as trials specifically aimed at assessing the effects of vitamin D supplementation in patients with osteosarcopenic obesity are not available, and trials that investigated the role of vitamin D on muscle and bone health in other patient populations either showed no or even detrimental effects. We conclude that large observational and interventional studies including individuals with osteosarcopenic obesity representative of different sex, age and race are needed to better define the role of vitamin D in the pathogenesis and treatment of this condition.

Influence of Obesity on Bone Turnover Markers and Fracture Risk in Postmenopausal Women

Background and aims: The relationship between obesity and bone metabolism is controversial. In recent decades, the protective role of obesity in the development of osteoporosis is questioned. The aims of this study are the following: to evaluate the differences in bone turnover markers between postmenopausal women with and without obesity and to compare the risk of fracture at five years between these groups. Methods: An observational longitudinal prospective cohort study of postmenopausal women with obesity (O) (body mass index (BMI) > 30 kg/m2) and non-obesity (NoO) (BMI < 30 kg/m2) is designed. 250 postmenopausal women are included in the study (NoO: 124 (49.6%) and O: 126 (50.4%)). It measures epidemiological variables, dietary variables (calcium intake, vitamin D intake, smoking, alcohol consumption, and physical activity), biochemicals (β-crosslap, type I procollagen amino-terminal peptide (P1NP), 25OH-vitamin D, and parathyroid hormone (PTH)), anthropometric variables, and fracture data five years after the start of the study. The mean age is 56.17 (3.91) years. Women with obesity showed lower levels of vitamin D (O: 17.27 (7.85) ng/mL, NoO: 24.51 (9.60) ng/mL; p < 0.01), and higher levels of PTH (O: 53.24 (38.44−65.96) pg/mL, NoO: 35.24 (25.36−42.40) pg/mL; p < 0.01). Regarding the bone formation marker (P1NP), it was found to be high in women without obesity, O: 45.46 (34.39−55.16) ng/mL, NoO: 56.74 (45.34−70.74) ng/mL; p < 0.01; the bone resorption marker (β-crosslap) was found to be high in women with obesity, being significant in those older than 59 years (O: 0.39 (0.14) ng/mL, NoO 0.24 (0.09) ng/mL; p < 0.05). No differences are observed in the risk of fracture at 5 years based on BMI (OR = 0.90 (95%CI 0.30−2.72); p = 0.85). Conclusions: Postmenopausal women with obesity showed lower levels of bone formation markers; older women with obesity showed higher markers of bone resorption.

Vitamin D deficiency: a potential risk factor for cancer in obesity?

Obesity is considered an abnormal or excessive accumulation of adipose tissue, due to a prolonged positive energy balance that arises when energy intake is greater than energy expenditure, leading to an increased risk for the individual health and for the development of metabolic chronic diseases including several different types of cancer. Vitamin D deficiency is a metabolic alteration, which is often associated with the obesity condition. Vitamin D is a liposoluble vitamin, which plays a pivotal role in calcium-phosphate metabolism but extraskeletal effects have also been described. Among these, it plays an important role also in adipocyte physiology and glucose metabolism, typically dysregulated in subjects affected by obesity. Moreover, it is now recognized that Vitamin D also influences the processes of cell proliferation, differentiation, adhesion potentially leading to carcinogenesis. Indeed, data indicate a potential link between vitamin D levels and cancer, and higher vitamin D concentrations have been associated with a lower risk of developing different kinds of tumors, including breast, colon, lymphoma, lung, and prostate cancers. Thus, this review will revise the literature regarding this issue investigating and highlighting the potential mechanism of action, which might lead to new therapeutical options.

Hypocalcemia in COVID-19: Prevalence, clinical significance and therapeutic implications

COVID-19 extra-pulmonary features include several endocrine manifestations and these are becoming strongly clinically relevant in patients affected influencing disease severity and outcomes.At the beginning of COVID-19 pandemic no population data on calcium levels in patients affected were available and in April 2020 a first case of severe acute hypocalcemia in an Italian patient with SARS-CoV-2 infection was reported. Subsequently, several studies reported hypocalcemia as a highly prevalent biochemical abnormality in COVID-19 patients with a marked negative influence on disease severity, biochemical inflammation and thrombotic markers, and mortality. Also a high prevalence of vertebral fractures with worse respiratory impairment in patients affected and a widespread vitamin D deficiency have been frequently observed, suggesting an emerging "Osteo-Metabolic Phenotype" in COVID-19.To date, several potential pathophysiological factors have been hypothesized to play a role in determining hypocalcemia in COVID-19 including calcium dependent viral mechanisms of action, high prevalence of hypovitaminosis D in general population, chronic and acute malnutrition during critical illness and high levels of unbound and unsaturated fatty acids in inflammatory responses.Since hypocalcemia is a frequent biochemical finding in hospitalized COVID-19 patients possibly predicting worse outcomes and leading to acute cardiovascular and neurological complications if severe, it is reasonable to assess, monitor and, if indicated, replace calcium at first patient hospital evaluation and during hospitalization.

Effect of Vitamin D and Docosahexaenoic Acid Co-Supplementation on Vitamin D Status, Body Composition, and Metabolic Markers in Obese Children: A Randomized, Double Blind, Controlled Study

Obese children are at high risk of developing vitamin D deficiency. Omega-3 polyunsaturated fatty acids and their derivatives might have a beneficial effect on vitamin D status of obese children, due to their anti-inflammatory action, and increasing its absorption. This multicenter, randomized, double-blind controlled study aims to investigate the effect of vitamin D and docosahexaenoic acid (DHA) co-supplementation for six months on vitamin D status, body composition, and metabolic markers of obese children with vitamin D deficiency. A total of 108 children were enrolled and 73 children completed the study: 33 were supplemented with an oral dose of 500 mg of DHA and 1200 IU/day of vitamin D3 and 41 were supplemented with 1200 IU/day of vitamin D3 + wheat germ oil. At the end of the study, more than 50% of the subjects improved their vitamin D status. However, co-supplementation was not more effective than vitamin D plus wheat germ oil. Fat mass percentage was significantly reduced, and body mass index improved in both groups, even if all the subjects were still obese at the end of the study. Children receiving both vitamin D and DHA presented a higher increase of DHA levels that could be relevant to prevent inflammatory-associated complications of obesity, but they had no effect on vitamin D levels.

An Overview of Systematic Reviews of the Role of Vitamin D on Inflammation in Patients with Diabetes and the Potentiality of Its Application on Diabetic Patients with COVID-19

Almost two years have passed since the outbreak reported for the first time in Wuhan of coronavirus disease 2019 (COVID-19), due to severe acute respiratory syndrome (SARS)-CoV-2 coronavirus, rapidly evolved into a pandemic. This infectious disease has stressed global health care systems. The mortality rate is higher, particularly in elderly population and in patients with comorbidities such as hypertension, diabetes mellitus, cardiovascular disease, chronic lung disease, chronic renal disease, and malignancy. Among them, subjects with diabetes have a high risk of developing severe form of COVID-19 and show increased mortality. How diabetes contributes to COVID-19 severity remains unclear. It has been hypothesized that it may be correlated with the effects of hyperglycemia on systemic inflammatory responses and immune system dysfunction. Vitamin D (VD) is a modulator of immune-response. Data from literature showed that vitamin D deficiency in COVID-19 patients increases COVID-19 severity, likely because of its negative impact on immune and inflammatory responses. Therefore, the use of vitamin D might play a role in some aspects of the infection, particularly the inflammatory state and the immune system function of patients. Moreover, a piece of evidence highlighted a link among vitamin D deficiency, obesity and diabetes, all factors associated with COVID-19 severity. Given this background, we performed an overview of the systematic reviews to assess the association between vitamin D supplementation and inflammatory markers in patients with diabetes; furthermore, vitamin D’s possible role in COVID-19 patients was assessed as well. Three databases, namely MEDLINE, PubMed Central and the Cochrane Library of Systematic Reviews, were reviewed to retrieve the pertinent data. The aim of this review is to provide insight into the recent advances about the molecular basis of the relationship between vitamin D, immune response, inflammation, diabetes and COVID-19.

Simultaneous Determination of Vitamin D and Its Hydroxylated and Esterified Metabolites by Ultrahigh-Performance Supercritical Fluid Chromatography-Tandem Mass Spectrometry

In this study, an analytical method has been developed that, for the first time, allows simultaneous determination of vitamin D₂ and vitamin D₃ along with their hydroxylated and esterified forms. A group of 12 vitamin D analogues including vitamin D₂ and vitamin D₃, seven hydroxylated metabolites, and three ester forms were separated in a single 8.0 min run using ultrahigh-performance supercritical fluid chromatography coupled with triple quadrupole tandem mass spectrometry. Electrospray ionization and atmospheric pressure chemical ionization were investigated as ion sources, of which the latter showed a higher ionization efficiency. Chromatographic conditions were thoroughly evaluated by a step-by-step method, whereas an experimental design was applied for the optimization of the ionization parameters. Calibration and repeatability studies were carried out to validate the instrumental methodology showing determination coefficients higher than 0.9992 and good intra- and interday precision with relative standard deviations for areas and retention times lower than 10 and 2.1%, respectively, for all target analytes. Limits of quantification were below 3.03 μg/L for all compounds. The methodology was then validated and applied for the evaluation of human plasma samples in order to demonstrate its applicability to the analysis of vitamin D analogues in biological samples. Samples of five individuals were analyzed. Results show that linoleate-D₃, vitamin D₂, vitamin D₃, 25-hydroxyvitamin D₂, 24,25-dihydroxyvitamin D₃, and 1,25-dihydroxyvitamin D₃ could be detected in most samples, while the two latter also were quantified in all analyzed samples.

The Role of Macronutrients, Micronutrients and Flavonoid Polyphenols in the Prevention and Treatment of Osteoporosis

Osteoporosis is considered an age-related disorder of the skeletal system, characterized primarily by decreased bone mineral density (BMD), microstructural quality and an elevated risk of fragility fractures. This silent disease is increasingly becoming a global epidemic due to an aging population and longer life expectancy. It is known that nutrition and physical activity play an important role in skeletal health, both in achieving the highest BMD and in maintaining bone health. In this review, the role of macronutrients (proteins, lipids, carbohydrates), micronutrients (minerals—calcium, phosphorus, magnesium, as well as vitamins—D, C, K) and flavonoid polyphenols (quercetin, rutin, luteolin, kaempferol, naringin) which appear to be essential for the prevention and treatment of osteoporosis, are characterized. Moreover, the importance of various naturally available nutrients, whether in the diet or in food supplements, is emphasized. In addition to pharmacotherapy, the basis of osteoporosis prevention is a healthy diet rich mainly in fruits, vegetables, seafood and fish oil supplements, specific dairy products, containing a sufficient amount of all aforementioned nutritional substances along with regular physical activity. The effect of diet alone in this context may depend on an individual’s genotype, gene-diet interactions or the composition and function of the gut microbiota.

rs7041 and rs4588 Polymorphisms in Vitamin D Binding Protein Gene (VDBP) and the Risk of Diseases

The purpose of the study was to investigate the role of vitamin D binding protein (VDBP, DBP) and its polymorphism in the vitamin D pathway and human health. This narrative review shows the latest literature on the most popular diseases that have previously been linked to VDBP. Vitamin D plays a crucial role in human metabolism, controlling phosphorus and calcium homeostasis. Vitamin D binding protein bonds vitamin D and its metabolites and transports them to target tissues. The most common polymorphisms in the VDBP gene are rs4588 and rs7041, which are located in exon 11 in domain III of the VDBP gene. rs4588 and rs7041 may be correlated with differences not only in vitamin D status in serum but also with vitamin D metabolites. This review supports the role of single nucleotide polymorphisms (SNPs) in the VDBP gene and presents the latest data showing correlations between VDBP variants with important human diseases such as obesity, diabetes mellitus, tuberculosis, chronic obstructive pulmonary disease, and others. In this review, we aim to systematize the knowledge regarding the occurrence of diseases and their relationship with vitamin D deficiencies, which may be caused by polymorphisms in the VDBP gene. Further research is required on the possible influence of SNPs, modifications in the structure of the binding protein, and their influence on the organism. It is also important to mention that most studies do not have a specific time of year to measure accurate vitamin D metabolite levels, which can be misleading in conclusions due to the seasonal nature of vitamin D.

Vitamin D Levels Are Associated With Blood Glucose and BMI in COVID-19 Patients, Predicting Disease Severity

CONTEXT

A high prevalence of vitamin D (VD) deficiency in COVID-19 patients has been reported and hypothesized to increase COVID-19 severity likely because of its negative impact on immune and inflammatory responses. Furthermore, clear associations between hypovitaminosis D and fat body mass excess and diabetes, factors associated with COVID-19 severity, have been widely recognized.

OBJECTIVE

The aim of this study was to evaluate in COVID-19 patients the relationship between VD levels and inflammatory response, body mass index (BMI), blood glucose (GLU), and disease severity.

METHODS

Patients admitted to San Raffaele-Hospital for COVID-19 were enrolled in this study, excluding those with comorbidities and therapies influencing VD metabolism. 25-Hydroxyvitamin D levels, plasma GLU levels, BMI, and inflammatory parameters were evaluated at admission.

RESULTS

A total of 88 patients were included. Median VD level was 16.3 ng/mL and VD deficiency was found in 68.2% of patients. VD deficiency was found more frequently in male patients and in those affected by severe COVID-19. Regression analyses showed a positive correlation between VD and PaO2/FiO2 ratio, and negative correlations between VD and plasma GLU, BMI, neutrophil/lymphocyte ratio, C-reactive protein, and interleukin 6. Patients with both hypovitaminosis D and diabetes mellitus, as well those with hypovitaminosis D and overweight, were more frequently affected by a severe disease with worse inflammatory response and respiratory parameters, compared to those without or just one of these conditions.

CONCLUSION

We showed, for the first-time, a strict association of VD levels with blood GLU and BMI in COVID-19 patients. VD deficiency might be a novel common pathophysiological mechanism involved in the detrimental effect of hyperglycemia and adiposity on disease severity.

Vitamin D status is favorably associated with the cardiovascular risk factors in adults with obesity

BACKGROUND & AIMS

Previous investigations have been indicated that vitamin D deficiency is an amendable risk for cardiovascular disease (CVD) in the general populations. Limited data is available concerning the relationship of vitamin D status and risk factors of CVD in the individuals with obesity and the existing data are highly controversial. We investigated whether serum vitamin D situation is related to multiple traditional CVD risk factors in Iranian obese subjects.

METHODS

A cross-sectional study was done among 214 Iranian adults with obesity (94 males and 120 females) aged 20-60 years, who attended the specialized outpatient clinics in Zabol city. Participants were categorized as vitamin D sufficient, insufficient, and deficient according to their serum 25(OH)D concentrations. Afterward, the presence of hypercholesterolemia, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), high low-density lipoprotein cholesterol (LDL-C) as well as diabetes, hypertension, and high serum concentrations of high-sensitivity C-reactive protein (hs-CRP) as CVD risk factors were evaluated in the participants.

RESULTS

There was a noticeable regular trend regarding hypercholesterolemia (p = 0.008), high LDL-C (p = 0.024), hypertension (p = 0.021), and high hs-CRP (p < 0.0001) across various categories of vitamin D status. In adjusted model, vitamin D-deficient subjects were at higher risk for having hypercholesterolemia (OR: 3.22, p = 0.031), high LDL-C (OR: 2.37, p = 0.047), hypertension (OR: 2.32, p = 0.042), and high hs-CRP (OR: 5.49, p = 0.001) than ones with sufficient vitamin D status.

CONCLUSIONS

Vitamin D deficiency in obese subjects was found to be strongly related to higher risk of unfavorable lipid profile, hypertension, and high hs-CRP.

Vitamin D: Dosing, levels, form, and route of administration: Does one approach fit all?

The 4^th International Conference on Controversies in Vitamin D was held as a virtual meeting in September, 2020, gathering together leading international scientific and medical experts in vitamin D. Since vitamin D has a crucial role in skeletal and extra-skeletal systems, the aim of the Conference was to discuss improved management of vitamin D dosing, therapeutic levels and form or route of administration in the general population and in different clinical conditions. A tailored approach, based on the specific mechanisms underlying vitamin D deficiency in different diseases that were discussed, was recommended. Specifically, in comparison to healthy populations, higher levels of vitamin D and greater amounts of vitamin D were deemed necessary in osteoporosis, diabetes mellitus, obesity (particularly after bariatric surgery), and in those treated with glucocorticoids. Emerging and still open issues were related to target vitamin D levels and the role of vitamin D supplementation in COVID-19 since low vitamin D may predispose to SARS-CoV-2 infection and to worse COVID-19 outcomes. Finally, whereas oral daily cholecalciferol appears to be the preferred choice for vitamin D supplementation in the general population, and in most clinical conditions, active vitamin D analogs may be indicated in patients with hypoparathyroidism and severe kidney and liver insufficiency. Parenteral vitamin D administration could be helpful in malabsorption syndromes or in states of vitamin D resistance.Specific guidelines for desired levels of vitamin D should be tailored to the different conditions affecting vitamin D metabolism with the goal to define disease-specific normative values.

Nutritional Management in Bariatric Surgery Patients

The obesity epidemic, mainly due to lifestyle changes in recent decades, leads to serious comorbidities that reduce life expectancy. This situation is affecting the health policies of many nations around the world. Traditional measures such as diet, physical activity, and drugs are often not enough to achieve weight loss goals and to maintain the results over time. Bariatric surgery (BS) includes various techniques, which favor rapid and sustained weight loss. BS is a useful and, in most cases, the best treatment in severe and complicated obesity. In addition, it has a greater benefit/risk ratio than non-surgical traditional therapies. BS can allow the obese patient to lose weight quickly compared with traditional lifestyle changes, and with a greater probability of maintaining the results. Moreover, BS promotes improvements in metabolic parameters, even diabetes remission, and in the quality of life. These changes can lead to an increase of life expectancy by over 6 years on average. The nutrition of people before and after BS must be the subject of indications from a trained staff, and patients must be followed in the subsequent years to reduce the risk of malnutrition and the associated problems. In particular, it is still debated whether it is necessary to lose weight prior to surgery, a procedure that can facilitate the surgeon's work reducing the surgical risk, but at the same time, lengthens preparation times increasing the risks associated with concomitant pathologies. Furthermore, preventing nutritional deficiencies prior to the intervention can improve the results and reduce short- and long-term mortality.

Association of serum 25-hydroxyvitamin D concentration with anthropometric measures in children and adolescents: the CASPIAN-V study

BACKGROUND

Serum 25-hydroxyvitamin D (25(OH)D) concentrations reflect vitamin D status, with deficiency implicated as an underlying factor for many adverse health effects. This study aims to analyze the association between vitamin D status and different anthropometric measures in a large pediatric population.

METHODS

This nationwide cross-sectional study was conducted in 2019 in blood samples obtained from school students of 30 provinces in Iran. Participants were 2596 children and adolescents aged 7-18 years. Weight, height, waist circumference (WC), hip circumference (HC), neck circumference (NC), and wrist circumference (WrC) were measured. Body mass index (BMI) and waist-to-height ratio (W/HtR) were calculated. Serum 25(OH)D concentrations were measured using chemiluminescent immunoassay.

RESULTS

Participants consisted of 55% boys, 71.3% urban inhabitants, with a mean (SD) age of 12.1 (3.0) years. Overall, vitamin D deficiency was documented in 10.6% of participants, insufficiency in 60.4%, and sufficiency in 29% of the population studied. The mean of BMI and WC was higher in the vitamin D deficient than in the vitamin D sufficient group (19.31 kg/m² and 69.24 cm vs. 18.34 kg/m² and 65.73 cm, respectively, P < 0.01). Multivariate linear regression models revealed a significant association of vitamin D insufficiency with WC and W/HtR (P < 0.05). Likewise, in the multivariate regression models, vitamin D deficiency was associated with BMI, WC, and W/HtR (P < 0.05).

CONCLUSION

Our findings on the inverse association between vitamin D status and some anthropometric measures underscore the importance of providing vitamin D by fortification and supplementation programs of vitamin D for the pediatric population.

LEVEL OF EVIDENCE

V.

Vitamin D in pediatric patients with obesity and arterial hypertension

The purpose of this study was to find potential differences in vitamin D levels between different groups: overweight children with hypertension, normal-weight children with hypertension, overweight children with normal blood pressure and normal-weight children without hypertension, representing the control group. We also wanted to determine whether there are correlations between vitamin D levels and other clinical laboratory parameters, to evaluate the potential need for substitution. We measured vitamin D, homocysteine, total cholesterol, HDL, LDL, triglycerides, uric acid, glucose, apolipoprotein A1, apolipoprotein B, alkaline phosphatase, calcium, phosphate and magnesium serum levels in all groups. We also took anthropometric measurements (body weight, height, body mass index (BMI)) and observed patients' blood pressure. The results were analyzed with SPSS statistic tool with basic statistical methods. The study included 175 children between 5 and 18 years of age. Fiftyseven were healthy (group A-control group), 41 normal-weight with hypertension (group B), 44 overweight with hypertension (group C) and 33 overweight with normal blood pressure (group D). The results showed statistically significant differences in values of vitamin D between all groups-A and B (p = 0.003), A and C (p < 0.001), A and D (p < 0.001), B and D (p = 0.043), B and C (0.030), except for groups C and D (p = 0.830). There were statistically significant correlations between vitamin D and BMI (r = - 0.196, p = 0.010), systolic pressure (r = - 0.190, p = 0.002), diastolic pressure (r = - 0.149, p = 0.050), homocysteine (r = - 0.208, p = 0.007), triglycerides (r = - 0.196, p = 0.011) and apolipoprotein A1 (r = 0.222, p = 0.007), confirmed in multivariate model. For the blood pressure, the higher the systolic blood pressure, the lower the average vitamin D was. The pilot study shows significant differences in serum vitamin D levels between all groups of children, apart from groups C and D. These results, combined with statistically significant correlations between vitamin D and systolic and diastolic blood pressure suggest the need for monitoring and potential substitution of vitamin D in in pediatric patients with hypertension.