Vitamin D status and calcium intake in systemic inflammation, insulin resistance and the metabolic syndrome: An update on current evidence

Insight into the Interaction Mechanism of Vitamin D against Metabolic Syndrome: A Meta-Analysis and In Silico Study

As a dietary supplement or functional food additive, vitamin D (VD) deficiency may impact extra-skeletal functions associated with metabolic syndrome (MetS) risk factors. However, the precise effects and mechanisms of VD supplementation on dyslipidemia and insulin resistance in MetS subjects remain controversial. Here, we investigate potential therapeutic targets, pathways and mechanisms of VD against MetS through a comprehensive strategy including meta-analysis, network pharmacology analysis, molecular docking, dynamics simulations, and quantum chemical calculations. Our results reveal that VD supplementation significantly reduces triglyceride levels, fasting glucose, and insulin concentrations in subjects, thereby improving insulin homeostasis to some extent. We theoretically identify 14 core MetS-associated targets. Notably, VD exhibits substantial interactions with three targets (PPARγ, FABP4, and HMGCR) in the PPAR signaling pathway, indicating that VD can modulate this pathway. Van der Waals forces predominantly stabilize the complexes formed between VD and the three targets. Nonetheless, to provide valuable insights for personalized MetS management, further research is necessary to confirm our findings, emphasizing the importance of exploring genetic variability in VD response. In conclusion, our study contributes insights into the mechanisms of VD in preventing and treating MetS through dietary supplementation, promoting the development of VD-based functional foods or nutritious diets.

Triglycerides and systolic blood pressure negatively mediate the direct relationship of vitamin D status to resting energy expenditure: A cross sectional analysis

BACKGROUND AND AIMS

We determined whether individual components of metabolic syndrome (MetS) mediated the direct association of vitamin D status (25OHD) on resting energy expenditure (REE).

METHODS

Multiple linear regression determined predictors of REE from data on 180 men and women from two ethnic groups. We then modelled a mediation pathway through components of MetS on the direct association between 25OHD and REE. The mediation modelling used the PROCESS SPSS Macro (version 4.0) based on 5000 bootstrapped samples, with the adjustment for different sets of covariates.

RESULTS

REE was significantly predicted by age, fat mass (FM), fat free mass (FFM), ethnicity, inverse ln insulin, 25OHD, triglycerides (TG), systolic blood pressure (SBP) and, to some extent, by time of REE measurements (p < 0.094). Adjustment for all these covariates, resulted in a negative indirect mediation effect of TG [β coefficient (bootstrapped SE): 0.95 (0.519); bootstrapped 95% CI: 2.172, -0.165; p < 0.05] and a concurrent negative mediation of SBP [β coefficient (bootstrapped SE): 0.72(0.484); bootstrapped 95% CI: 1.851, -0.011; p < 0.05]. There remained a positive direct pathway from 25OHD to REE [β coefficient (S.E): 4.715 (2.129); p = 0.028], however the total effect of 25OHD was dampened [β coefficient (S.E): 3.04 (2.126); p = 0.154].

CONCLUSIONS

Independent of insulin sensitivity, a negative mediation by TG and SBP dampened the overall effect of 25OHD on REE.

The Impact of the Metabolic Syndrome and Its Components on Resting Energy Expenditure

We determined whether metabolic syndrome (MetS) and the increasing number of its components influenced the resting energy expenditure (REE). Data on adult men (n = 72, 40%) and women (n = 108, 60%) from European (n = 154, 86%) and Sub-Saharan African (n = 26, 14%) ancestry were used. Ninety-five (53%) participants had MetS (MetS+), while 85 (47%) were without MetS (MetS−). REE was determined through indirect calorimetry, body composition by DEXA, and clinical biochemistry by standard laboratory techniques. MetS+ had a significantly higher REE (mean ± se: MetS+: 5995 ± 87.3 vs. MetS−: 5760 ± 86.3 kJ/d, p = 0.025) when adjusted for age, gender, fat mass (FM), fat-free mass (FFM), ethnicity, season, 25OHD, insulin sensitivity, and time of data collection. Within each MetS status group, an increase in the number of components (C) resulted in a stepwise increase in REE. Relative to zero components, those with 1C had adjusted REE higher by +526 ± 248.1 kJ/d (p = 0.037), while 2C were higher than 1C by +298 ± 140.8 kJ/d (p = 0.037). Similarly, relative to 3C, those with 4C had REE higher by +242 ± 120.7 kJ/d (p = 0.049). The higher REE of 5C over 4C by 132 ± 174.5 kJ/d did not achieve statistical significance. MetS was associated with a significantly higher REE. This greater energetic cost varied directly with the numbers of its components but was most evident in those not diagnosed with the syndrome.

Influence of strains and environmental cultivation conditions on the bioconversion of ergosterol and vitamin D2 in the sun mushroom

BACKGROUND

The fungus Agaricus subrufescens is grown commercially in China, the USA, Brazil, Taiwan and Japan, among others. However, each country adopts a cultivation system that significantly influences the agronomical parameters and chemical composition of the harvested mushrooms. In this study, the influence of the cultivation process on the content of ergosterol and vitamin D₂ was evaluated.

RESULTS

Four commercial strains of A. subrufescens (ABL 04/49, ABL CS7, ABL 18/01 and ABL 19/01) and two environmental cultivation conditions (in the field and a controlled chamber with the absence of sunlight) were used. Infield cultivation, ABL CS7 and ABL 19/01 strains presented better agronomic parameters, whereas in a protected environment ABL 19/01, ABL 04/49 and ABL 18/01 demonstrated better performance, respectively. The highest biological efficiency value (64%) was provided by ABL 19/01 strain in a controlled environment.

CONCLUSION

The highest content in ergosterol (990 mg kg^-1 ) and vitamin D₂ (36.8 mg kg^-1 ) were observed in mushrooms obtained in the field from strain ABL 04/49, which presents reasonable agronomic parameters for cultivation. © 2021 Society of Chemical Industry.

Metabolically Healthy Obesity and Bariatric Surgery

A peculiar category of persons with obesity lacking common metabolic disturbances has been depicted and termed as metabolically healthy obesity (MHO). Yet, although MHO patients are free of obesity-associated complications, they might not be entirely precluded from developing cardio-metabolic disorders. Among patients with morbid obesity (MO) who are referred to bariatric surgery, a subset of metabolically healthy MO (MHMO) has been identified and the question arises if these patients would benefit from surgery in terms of mitigating the peril of cardio-metabolic complications. We revisited the pathophysiological mechanisms that define MHO, the currently available data on the cardio-metabolic risk of these patients and finally we reviewed the benefits of bariatric surgery and the urge to better characterize MHMO before submission to surgery.

Prospective associations between total, animal, and vegetable calcium intake and metabolic syndrome in adults aged 40 years and older

BACKGROUND & AIMS

Calcium (Ca) consumption may contribute to a decreased risk of developing metabolic syndrome (MetS). However, epidemiologic evidence on the association between Ca intake and MetS is limited. This study aimed to evaluate the association between dietary Ca intake (animal-based Ca and vegetable-based Ca separately, as well as total Ca intake) and the incidence risk of MetS and its components in the Korean Multi-Rural Communities Cohort (MRCohort).

METHODS

A total of 5509 participants who did not have MetS were enrolled. Dietary Ca intake was calculated using a food frequency questionnaire composed of 106 items.

RESULTS

After 18,880 person-years of follow-up, 876 participants had developed de novo MetS. A significant inverse association between dietary total Ca intake and MetS were observed (incidence rate ratio (IRR) = 0.62, 95% confidence interval (CI) = 0.48-0.81, P for trend = 0.002 for the highest quartile of total Ca intake compared with the lowest quartile). Trends for animal Ca (IRR = 0.77, 95% CI = 0.62-0.97, P for trend = 0.039) and vegetable Ca (IRR = 0.54, 95% CI = 0.40-0.73, P for trend <0.001) were similar. The individual components of overall MetS were also inversely related to total, animal, and vegetable Ca. The tendency for an inverse association was more evident in the group with two of any of the metabolic abnormalities of MetS at baseline than in the group with no more than one MetS component.

CONCLUSIONS

Our findings indicate that a relatively high dietary intake of Ca is associated with lower risk of MetS.

Vitamin D status is inversely associated with markers of risk for type 2 diabetes: A population based study in Victoria, Australia

A growing body of evidence suggests a protective role of vitamin D on the risk of type 2 diabetes mellitus (T2DM). We investigated this relationship in a population sample from one Australian state. The data of 3,393 Australian adults aged 18-75 years who participated in the 2009-2010 Victorian Health Monitor survey was analyzed. Socio-demographic information, biomedical variables, and dietary intakes were collected and fasting blood samples were analyzed for 25, hydroxycholecalciferol (25OHD), HbA1c, fasting plasma glucose (FPG), and lipid profiles. Logistic regression analyses were used to evaluate the association between tertiles of serum 25OHD and categories of FPG (<5.6 mmol/L vs. 5.6-6.9 mmol/L), and HbA1c (<5.7% vs. 5.7-6.4%). After adjusting for social, dietary, biomedical and metabolic syndrome (MetS) components (waist circumference, HDL cholesterol, triglycerides, and blood pressure), every 10 nmol/L increment in serum 25OHD significantly reduced the adjusted odds ratio (AOR) of a higher FPG [AOR 0.91, (0.86, 0.97); p = 0.002] and a higher HbA1c [AOR 0.94, (0.90, 0.98); p = 0.009]. Analysis by tertiles of 25OHD indicated that after adjustment for socio-demographic and dietary variables, those with high 25OHD (65-204 nmol/L) had reduced odds of a higher FPG [AOR 0.60, (0.43, 0.83); p = 0.008] as well as higher HbA1c [AOR 0.67, (0.53, 0.85); p = 0.005] compared to the lowest 25OHD (10-44 nmol/L) tertile. On final adjustment for other components of MetS, those in the highest tertile of 25OHD had significantly reduced odds of higher FPG [AOR 0.61, (0.44, 0.84); p = 0.011] and of higher HbA1c [AOR 0.74, (0.58, 0.93); p = 0.041] vs. low 25OHD tertile. Overall, the data support a direct, protective effect of higher 25OHD on FPG and HbA1c; two criteria for assessment of risk of T2DM.