High prevalence of vitamin D insufficiency and its association with obesity and metabolic syndrome among Malay adults in Kuala Lumpur, Malaysia

Vitamin D3 mitigates myopathy and metabolic dysfunction in rats with metabolic syndrome: the potential role of dipeptidyl peptidase-4

Metabolic syndrome is associated with vitamin D3 deficiency. This work aims to examine the efficacy of vitamin D3 in inhibiting MetS-induced myopathy and to determine whether the beneficial effects of vitamin D3 are mediated by the inhibition of dipeptidyl peptidase-4 (DPP-4). An in silico study investigated the potential effectiveness of vitamin D3 on the inhibition of the DPP-4 enzyme. An in vitro assay of the DPP-4 inhibitory effect of vitamin D3 was performed. In vivo and over 12 weeks, both diet (with 3% salt) and drinking water (with 10% fructose) were utilized to induce MetS. In the seventh week, rats received either vitamin D3, vildagliptin, a combination of both, or vehicles. Serum lipids, adipokines, glycemic indices, and glucagon-like peptide-1 (GLP-1), muscular glucose transporter type-4 (GLUT-4) content, DPP-4, adenosine monophosphate kinase (AMPK) activities, and Sudan Black B-stained lipids were assessed. Muscular reactive oxygen species (ROS), caspase-3, and desmin immunostaining were used to determine myopathy. MetS-induced metabolic dysfunction was ameliorated by vitamin D3, which also reduced intramuscular glycogen and lipid accumulation. This is demonstrated by the attenuation of MetS-induced myopathy by vitamin D3, decreased oxidative stress, increased desmin immuno-expression, and caspase-3 activity. Our in silico data demonstrated that vitamin D3 is capable of inhibiting DPP-4, which is further supported by biochemical findings. Vitamin D3 increased serum GLP-1, muscular AMPK activity, and GLUT-4 content, whereas the levels of muscular ROS were decreased in MetS. Vildagliptin and its combination with vitamin D3 yielded comparable results. It is suggested that the DPP-4 inhibitory potential of vitamin D3 is responsible for the amelioration of MetS-induced metabolic changes and myopathy.

Telmisartan ameliorates nephropathy and restores the hippo pathway in rats with metabolic syndrome

The main objective of this study was to determine if the telmisartan-ameliorative effects of metabolic syndrome (MetS)-evoked nephropathy are attributed to the Hippo pathway. A secondary objective was to investigate the potential of vitamin D3 to enhance telmisartan-favourable effects. A diet composed of 24% fat and 3% salt, along with drinking water containing 10% fructose, was administered for 12 weeks to induce MetS. MetS-rats were given telmisartan (5 mg/kg/day), vitamin D3 (10 μg/kg/day) or both by gavage, starting in the sixth week of experimental diet administration. Assessments performed at closure included renal function, histological examination, catalase, malondialdehyde (MDA), nuclear factor kappa-B (NF-κB), interleukin-6 (IL-6), peroxisome proliferator-activated receptor-γ (PPAR-γ), phosphatase and tensin homolog (PTEN), and transforming growth factor-β (TGF-β). Matrix metalloproteinase-9 (MMP-9) immunostaining was conducted. The expression of the Hippo pathway components, as well as that of angiotensin II type 1 and type 2 (AT1 and AT2), receptors was evaluated. Telmisartan attenuated MetS-evoked nephropathy, as demonstrated by improvement of renal function and histological features, enhancement of catalase, reduction of MDA, inflammation (NF-κB, IL-6), and renal fibrosis (increased PPAR-γ and PTEN and reduced MMP-9 and TGF-β). Telmisartan downregulated AT1-receptor, upregulated AT2-receptor and restored the Hippo pathway. Vitamin D3 replicated most of the telmisartan-elicited effects and enhanced the antifibrotic actions of telmisartan. The alleviative effects of telmisartan on MetS-evoked nephropathy may be related to the restoration of the Hippo pathway. The combination of vitamin D3 and telmisartan exerted more favourable effects on metabolic and nephropathic biomarkers compared with either one administered alone.

Assessment of serum vitamin D levels in children aged 0-17 years old in a Chinese population: a comprehensive study

Vitamin D deficiency and insufficiency pose global public health challenges, yet research on serum vitamin D levels in the 0-17-year-old age group in southeastern China remains limited. This study aimed to fill this gap by investigating serum 25(OH)D levels in children in the region aged 0-17 years, contributing crucial data for understanding vitamin D nutritional status. Liquid chromatography‒mass spectrometry/mass spectrometry (LC‒MS/MS) technology was used. Vitamin D testing was integrated into routine diagnostic procedures for 11,116 children in Wujiang District, Suzhou City. Among the 0-17-year age group, comprising 6348 boys and 4768 girls, the prevalence of serum 25(OH)D deficiency and insufficiency was 21.4% and 31.0%, respectively. The median serum 25(OH)D concentration was 29.72 ng/mL (21.84-39.84 ng/mL) in boys compared to 28.48 ng/mL (20.65-39.23 ng/mL) in girls. Seasonal variations were observed, with median serum 25(OH)D concentrations of 29.02 ng/mL (20.73-39.72 ng/mL) in spring, 28.79 ng/mL (21.53-39.37 ng/mL) in summer, 30.12 ng/mL (22.00-39.70 ng/mL) in autumn, and 28.58 ng/mL (19.97-39.46 ng/mL) in winter. Statistically significant differences were noted in the serum 25(OH)D levels during autumn and winter. In conclusion, the rate of adequate vitamin D levels in local children was 47.5%, revealing a relatively high prevalence of vitamin D deficiency (21.4%) and insufficiency (31.0%), especially during the post-preschool period. Advocating for vitamin D supplementation in children is crucial for ensuring adequate vitamin D support.

Obstructive sleep apnea and vitamin D: an updated systematic review and meta-analysis

PURPOSE  : Obstructive sleep apnea (OSA) is a chronic, sleep-related breathing disorder which leads to increased cardiovascular risks. Vitamin D deficiency is associated with various cardiometabolic complications, including increased cardiovascular morbidity and mortality. We aimed to analyze the difference in serum 25-hydroxyvitamin D (25-OHD) level, prevalence of vitamin D insufficiency and deficiency, and the effect of CPAP treatment on serum 25-OHD levels among adult patients with OSA.

METHODS

We pooled data from 18 observational studies involving 5592 individuals. Baseline parameters that might have contributed to the significant differences observed were also analyzed.

RESULTS

Patients with OSA had significantly lower serum 25-OHD levels (pooled d +  - 0.74 [95% CI: - 1.19 to - 0.28], p < 0.01) and higher prevalence of vitamin D deficiency (pooled log (odds ratio) 0.98 [95% CI: 0.30 to 1.67], p < 0.01) compared to those without OSA. Subgroup analysis demonstrated that these differences were significant only in moderate OSA and severe OSA. Neither age nor BMI nor geographical latitude contributed significantly to the differences observed in serum 25-OHD levels. The use of CPAP did not lead to significant changes in serum 25-OHD levels.

CONCLUSION

Patients with OSA have lower serum 25-OHD levels with a higher prevalence of vitamin D deficiency, regardless of age or BMI, pointing to an independent association between vitamin D and OSA.

Prevalence and predictors of vitamin D deficiency among adults with epilepsy: A cross-sectional study

BACKGROUND

Vitamin D deficiency among adult people with epilepsy (PWE) is scarcely studied, despite its essential role in bone health and maintaining homeostasis. Several studies have studied the relationship between factors related to epilepsy and vitamin D metabolism. We aim to investigate this in our multi-ethnic society.

METHODS

This was a single-center cross-sectional study. We recruited 159 participants diagnosed with epilepsy on antiseizure medications (ASMs). We included those aged 18 years and above, excluding patients with long-term medical conditions that would affect vitamin D metabolism. Sociodemographic data and details of epilepsy were collated. Venous sampling was performed to analyze the levels of albumin-corrected calcium, phosphate, alkaline phosphatase, and 25-hydroxyvitamin D3 [25(OH)D]. Serum 25(OH)D level is defined as deficient (<20 ng/ml), insufficient (20-29 ng/ml), and sufficient (≥30 ng/ml).

RESULTS

The study reported that 73 (45.9%) participants had vitamin D deficiency, 38 (23.9%) had vitamin D insufficiency, and 48 (30.2%) patients had sufficient vitamin D levels. The predictors identified were PWE aged 18 to 44 years old (p = 0.001), female gender (OR 3.396, p = 0.002), and ethnicity (p < 0.001), specifically Malay and Chinese. However, no significant association was identified between types of ASMs, serum calcium, or the prevalence of vitamin D deficiency.

CONCLUSION

Vitamin D deficiency among PWE is prevalent in our local population, suggesting that regular screening should be considered for those at risk. Early identification would allow intervention to reduce the risk of future complications.

Fragility fracture care gap at a tertiary teaching hospital in Malaysia

Fracture begets fracture, pharmacological treatment is needed to prevent secondary fractures. This study found that there was a fragility fracture care gap where both bone health investigations and treatment initiation rates were low. Strategies such as Fracture Liaison Service is needed to address the care gap.

PURPOSE

This study aimed to investigate the clinical burden and secondary fracture prevention of fragility fractures at a tertiary teaching hospital in Malaysia.

METHODS

Electronic medical records of all patients admitted with fragility fractures between 1 January 2017-31 December 2018 were reviewed. Patients < 50 years old, with non-fragility fractures, restricted access to medical records, transferred to another hospital or who passed away during admission were excluded. Descriptive statistics were used to summarise patients' characteristics, frequency of fragility fractures, and secondary fracture prevention details. Binomial logistic regression was performed to analyse predictive factors for post-fracture bone health assessments and treatment initiation.

RESULTS

1030 patients [female (767/1030, 74.5%)] presented with 1071 fractures [hip fractures (378/1071, 35.3%)]. 170/993 (17.1%) patients were initiated on anti-osteoporosis medications (AOMs) and 148/984 (15.0%) had bone mineral density (BMD) performed within 1-year post-fracture. Less than half (42.4%) of the patients remained on treatment at 1-year post-fracture. Older patients [65-74 years old: odds ratio (OR) = 2.18, 95%CI 1.05-4.52, p = 0.04; ≥ 75 years: OR = 3.06, 95%CI 1.54-6.07, p < 0.01], hip fractures (OR = 1.95, 95%CI 1.23-3.11, p < 0.01), Chinese ethnicity (OR = 1.90, 95%CI 1.07-3.35, p = 0.03),previously diagnosed with osteoporosis (OR = 2.65, 95%CI:1.32-5.31, p < 0.01) and a BMD test performed (OR = 12.48, 95%CI 8.04-19.37, p < 0.01) were found to have higher AOM initiation. Patients with past diagnosis of osteoporosis (OR = 4.45, 95%CI 2.25-8.81, p < 0.01) and initiated on AOM (OR = 11.34, 95%CI 7.57-16.97, p < 0.01) had a higher likelihood to undergo BMD testing.

CONCLUSION

The AOM initiation and BMD testing rates were low. There is a need to address the fragility fracture care gap with strategies such as Fracture Liaison Service.

Serum 25-hydroxyvitamin D levels and dyslipidemia: a systematic review and dose-response meta-analysis of epidemiologic studies

CONTEXT

Findings of previous observational studies that examined the association between circulating vitamin D levels and lipid profiles have been inconsistent.

OBJECTIVE

A dose-response meta-analysis of epidemiologic studies was conducted to investigate the relationship between serum 25-hydroxyvitamin D levels and dyslipidemia in adults.

DATA SOURCES

Electronic databases were searched systematically for articles published up to June 2021.

DATA EXTRACTION

Fifty-seven observational studies and 2 cohort studies that reported odds ratios (ORs) or relative risks (RRs) with 95%CIs for dyslipidemia in relation to serum 25-hydroxyvitamin D levels in adults were included.

DATA ANALYSIS

A high level, vs a low level, of serum 25-hydroxyvitamin D was related to a significant 19% decrease in the odds of hypertriglyceridemia (OR 0.81; 95%CI, 0.74-0.89), an 18% reduction in low high-density lipoprotein cholesterol (HDL-C) (OR 0.82; 95%CI, 0.76-0.89), and an 18% reduction in dyslipidemia (OR 0.82; 95%CI, 0.75-0.91). No significant association was found between a high vs a low level of serum 25-hydroxyvitamin D and risk of high low-density lipoprotein cholesterol (LDL-C) levels (OR 0.86; 95%CI, 0.62-1.19) or hypercholesterolemia (OR 1.03; 95%CI, 0.93-1.15). Dose-response analyses demonstrated that each 10 ng/mL increase in the serum 25-hydroxyvitamin D level was linked, respectively, to a 7% (OR 0.93;95%CI, 0.85-1.02), a 3% (OR 0.97; 95%CI, 0.90-1.05), and a 4% (OR 0.96; 95%CI, 0.92-1.00) marginally significant decrease in the odds of hypertriglyceridemia, low HDL-C, and dyslipidemia.

CONCLUSION

Higher serum 25-hydroxyvitamin D levels are associated with significant reductions in the odds of hypertriglyceridemia, low HDL-C, and dyslipidemia in a dose-response trend.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42021219484.

Vitamin D insufficiency is high in Malaysia: A systematic review and meta-analysis of studies on vitamin D status in Malaysia

PURPOSE

To estimate the vitamin D status of participants residing in Malaysia.

METHODS

PubMed, Scopus, Web of Science, and MyJurnal were searched up to June 2022 without language restrictions. Studies that reported the 25-hydroxyvitamin D [25(OH)D] concentrations and defined their cut-off for deficiency or insufficiency from healthy participants residing in Malaysia were included. The random effects model was used to pool vitamin D status using established cut-offs of <30, <50, and <75 nmol/L according to age group.

RESULTS

From 299 studies screened, 32 studies were included in the meta-analysis. The pooled proportion for <30 nmol/L was 21% (95% CI 9-36, n = 2,438 from 10 studies), while the pooled proportion <50 nmol/L was 64% (95% CI 56-72, n = 13,977 from 30 studies), and <75 nmol/L was 85% (95% CI 61-100, n = 1,376 from five studies). Heterogeneity was high (I2 ranged from 98-99%). Higher proportions of vitamin D insufficiency (defined as <50 nmol/L) were found in participants living in the urban areas (compared to rural areas), in females (compared to males), and in Malays and Malaysian Indians (compared to Malaysian Chinese) ethnicities.

CONCLUSION

More than half of Malaysians have insufficient vitamin D levels, despite being a country that is close to the equator. We strongly urge prompt public health measures to improve the vitamin D status in Malaysia.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021260259].

Plasma parathyroid hormone response to vitamin D3 supplementation among women of reproductive age: A randomized double-blind placebo-control trial

While vitamin D inadequacy occurs worldwide, there is a lack of consensus internationally on the optimum plasma levels of 25(OH)D to maximally suppress the level of parathyroid hormone toward reducing bone loss. This study aimed to investigate the response of intact parathyroid hormone (iPTH) to vitamin D3 supplementation among Malaysian women of reproductive age in a randomised double-blind placebo-control trial [NMRR-15-479-25680]. A total of 106 women who fulfilled the study inclusion criteria were randomly assigned to receive daily one of these three supplement doses (i) 600 IU vitamin D3 + 500 mg calcium; (ii) 1200 IU vitamin D3 + 500 mg calcium; or (iii) 4000 IU vitamin D3 + 500 mg calcium. The placebo group received daily 500 mg calcium. The outcome examined was change in plasma iPTH concentration in response to daily vitamin D3 supplementation for 16 weeks. Fasting blood sample was obtained at baseline and post-supplementation. A total of 78 subjects (73.6%) completed the intervention. None of the supplementation groups brought about any detectable suppression of iPTH concentration post-supplementation. Vitamin D3 supplementation resulted in overall increase in plasma 25(OH)D levels, but only the 4000 IU/day group showed a significant dose effect post-supplementation (mean 49.7 ± 26.5 nmol/L) compared to placebo (29.3 ± 13.3 nmol/L). The lack of iPTH suppression is attributed to high prevalence of vitamin D insufficiency at baseline and the supplementation regimen was inadequate to raise the 25(OH)D level to cause PTH suppression. Inadequate calcium intake of the participants was also a likely contributing factor to the result. As prolonged vitamin D insufficiency and hypocalcaemia could lead to a compensatory rise in PTH resulting in accelerated bone loss, as well as posing increasing risks of non-skeletal morbidities, further clinical trials with an adequately powered sample size should be undertaken over an appropriate study duration to verify the results obtained in this study.

Three-dimensional optical body shape and features improve prediction of metabolic disease risk in a diverse sample of adults

OBJECTIVE

This study examined whether body shape and composition obtained by three-dimensional optical (3DO) scanning improved the prediction of metabolic syndrome (MetS) prevalence compared with BMI and demographics.

METHODS

A diverse ambulatory adult population underwent whole-body 3DO scanning, blood tests, manual anthropometrics, and blood pressure assessment in the Shape Up! Adults study. MetS prevalence was evaluated based on 2005 National Cholesterol Education Program criteria, and prediction of MetS involved logistic regression to assess (1) BMI, (2) demographics-adjusted BMI, (3) 85 3DO anthropometry and body composition measures, and (4) BMI + 3DO + demographics models. Receiver operating characteristic area under the curve (AUC) values were generated for each predictive model.

RESULTS

A total of 501 participants (280 female) were recruited, with 87 meeting the criteria for MetS. Compared with the BMI model (AUC = 0.819), inclusion of age, sex, and race increased the AUC to 0.861, and inclusion of 3DO measures further increased the AUC to 0.917. The overall integrated discrimination improvement between the 3DO + demographics and the BMI model was 0.290 (p < 0.0001) with a net reclassification improvement of 0.214 (p < 0.0001).

CONCLUSIONS

Body shape measures from an accessible 3DO scan, adjusted for demographics, predicted MetS better than demographics and/or BMI alone. Risk classification in this population increased by 29% when using 3DO scanning.

25-hydroxyvitamin D levels are inversely related to metabolic syndrome risk profile in northern Chinese subjects without vitamin D supplementation

BACKGROUND

The comparatively low 25 hydroxyvitamin D [25(OH)D] levels have been reported in patients with metabolic syndrome (MetS). Herein we investigated the cross-sectional and longitudinal relationships between serum 25(OH)D levels and MetS risk profile in northern middle-aged Chinese subjects without vitamin D supplementation.

METHODS

A cohort of 211 participants including 151 MetS patients and 60 controls at 20-69 years of age were enrolled from suburban Beijing, China. The recruited MetS patients were subjected to diet and exercise counselling for 1-year. All subjects at baseline and MetS patients after intervention underwent clinical evaluations.

RESULTS

Serum 25(OH)D levels were significantly decreased in MetS patients. 25(OH)D levels were inversely related to MetS score, fasting blood glucose (FBG) and triglyceride-glucose index (TyG) after adjusting for cofounders (all P < 0.05). Participants in the lowest tertile of 25(OH)D levels had increased odds for MetS (P = 0.045), elevated FBG (P = 0.004) in all subjects, and one MetS score gain in MetS patients (P = 0.005). Longitudinally, the metabolic statuses as well as 25(OH)D levels of MetS patients were significantly improved (all P < 0.05), and the increase of 25(OH)D levels were inversely related to MetS scores, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), FBG, and TyG, while positively related to high-density lipoprotein cholesterol (HDL-C) after adjusting for confounders.

CONCLUSIONS

25(OH)D levels were significantly decreased in MetS patients, and it was negatively associated with metabolic dysfunctions at baseline and 1-year after. Metabolic aberrations of MetS patients were significantly ameliorated with 1-year follow-up counselling accompanying by notably elevated 25(OH)D levels.

An Update on Vitamin D Deficiency Status in Malaysia

Vitamin D is essential for maintaining serum calcium levels, ensuring sufficient bone mineralization, immunomodulatory properties, and a protective effect on the cardiovascular system, renal disease, cancer, as well as in pregnancy. Vitamin D deficiency is prevalent worldwide, and it is not related to a country's development index. However, the data on vitamin D deficiencies are primarily taken from out-of-date, small-scale studies on target age groups or specific diseases, rather than from large-scale, population-based surveys. In Malaysia, for the past 16 years, studies were conducted involving adult men and women, pregnant women, postmenopausal women, adolescent, and children especially with specific diseases such as spina bifida, epilepsy, chronic liver disease, and atopic dermatitis. Only a few large surveys were conducted involving children and adolescents. Across the specific target population studied, vitamin D deficiency and insufficiency were seen particularly among females, Indians, and those of Malay ethnicity. This is related to widely known causes of vitamin D deficiency such as skin type (melanin) and sun avoidant lifestyles that include covering clothes, largely practiced by Malay Muslims in Malaysia. Other related causes or the high-risk groups are breastfed infants, the elderly, the obese, those on medications, and those characterized by fat malabsorption and geophysical factors. Vitamin D deficiency can be managed with pharmacological or non-pharmacological approaches, depending on the severity. The objective is to raise serum vitamin D to a normal level, hence, relieving the symptoms and reducing the adverse health outcomes. Despite no clear guidelines in treating vitamin D deficiency in Malaysia, this condition can be prevented with taking adequate vitamin D in food resources, sun exposure, or supplementation. Special attention should be given to high-risk groups including infants, obese patients, and the elderly.

Contribution of vitamin D status as a determinant of cardiometabolic risk factors: a structural equation model, National Food and Nutrition Surveillance

Background

Structural equation modeling (SEM) is a method used to evaluate linear causal relationships among variables. This study aimed to investigate the direct and indirect effects of serum 25(OH) D on certain cardiovascular risk factors using SEM.

Methods

An analytical cross-sectional study was conducted in six provinces of Iran. Subjects (n = 922), aged 19–65 years, were selected from National Food and Nutrition Surveillance. The assessments were sun-exposure behavior, anthropometric and biochemical measurements. A series of SEM models were tested and the model with the best fit indices was considered for use in the structural part of the model. Based on the literature review of previous theoretical models and supporting bivariate analyses, an overall SEM examined direct or indirect associations among observed and latent variables. We put the demographic, duration of sun exposure, anthropometric and metabolic variables in our model.

Results

The paths between serum 25(OH) D and BMI were inverse and statistically significant, whereas age showed a positive association with BMI (B = 0.06, p < 0.001), both direct (st. effect = 0.11, p = 0.01) and indirect via vitamin D (st. effect = − 0.02, p = 0.01). The results confirmed that serum 25(OH) D concentration is a predictor for latent variable of lipid profile (B = − 0.13, p = 0.01) both through direct (p = 0.02) and indirect effects via BMI (p = 0.01).

Conclusion

Serum 25(OH) D concentration is a predictor of BMI and also a latent variable of lipid profile via direct and indirect effects. It can also attenuate the harmful effect of age on BMI and lipid profile particularly in women.

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.

Association of Vitamin D status with Visceral Adiposity Index and Lipid Accumulation Product Index among a Group of Iranian People

There is a growing body of evidence linking vitamin D and its antiadipogenic activity with body composition. The aim of this study was to investigate the association between vitamin D levels, visceral adiposity index (VAI), and lipid accumulation product index among a group of Iranian people. This cross-sectional study was conducted with 270 Iranian adults. Body composition was measured via bio-impedance analysis. The 25-hydroxyvitamin D [25(OH)D] was also measured using the enzyme-linked immunosorbent assay method. The VAI and lipid accumulation product index were calculated. Multiple linear and logistic regression after controlling for confounder was used to report the results. Multiple linear regression showed that serum 25(OH)D levels were positively correlated with age (crude: β ± standard error [SE] = 0.23 ± 0.06, p ≤ 0.001; model I: β ± SE = 0.18 ± 0.05, p = 0.002) and percent body fat (crude: β ± SE = 0.10 ± 0.04, p = 0.02). Binary logistic regression analysis showed a higher chance of greater percent body fat and lipid accumulation product index in the crude model (odds ratio [OR], 2.05; 95% confidence interval [CI], 1.13–3.72 for percent body fat and OR, 2.07; 95% CI, 1.14–3.76 for lipid accumulation product index), which disappeared after adjusting for covariates. Adults with higher vitamin D levels had higher scores of percent body fat and lipid accumulation product index. More longitudinal studies are needed to confirm these results.

Serum vitamin D levels in relation to abdominal obesity: A systematic review and dose-response meta-analysis of epidemiologic studies

Although several observational studies have investigated the relationship between vitamin D deficiency and risk of central obesity, the results were inconsistent. We performed a dose-response meta-analysis on epidemiologic studies that evaluated the association of vitamin D status and abdominal obesity in adults. A systematic search was carried out of all published articles, up to May 2020, in five electronic databases, including MEDLINE (Pubmed), EMBASE, Institute for Scientific Information (ISI) (Web of science), Scopus and Google scholar. Forty-one observational studies reported odds ratios (ORs) or relative risks (RRs) with 95% confidence intervals (CIs) for abdominal obesity in relation to serum vitamin D levels in adults were included in the analysis. Using a random effects model, the overall effect size was calculated. Combining 44 effect sizes from 36 cross-sectional studies with 257,699 participants revealed that the highest versus the lowest serum vitamin D level was significantly associated with a 23% decreased odds of abdominal obesity (OR: 0.77; 95% CI [0.71, 0.83]). This inverse association was significant in almost all subgroups based on different covariates. Dose-response analysis showed that each 25 nmol/L increase in serum vitamin D was related to 8% reduced risk of abdominal obesity (OR: 0.92; 95% CI [0.85, 0.99]). When we confined the analysis to 23 effect sizes from 17 studies with representative population (242,135 participants), the same results were obtained (OR: 0.79; 95% CI [0.71, 0.87]). Dose-response analysis indicated that each 25 nmol/L increase in blood vitamin D levels was linked to 10% decreased central adiposity risk in representative populations (OR: 0.90; 95% CI [0.82, 0.99]). This meta-analysis of epidemiologic studies revealed that serum vitamin D level was inversely associated with risk of abdominal obesity in adults, in a dose-response manner. The same findings were obtained in representative populations. Further prospective studies are required to examine the causal association between serum vitamin D levels and abdominal obesity.

Total vs. Bioavailable: Determining a Better 25(OH)D Index in Association with Bone Density and Muscle Mass in Postmenopausal Women

The concurrent presence of low bone density (osteopenia/osteoporosis) and low muscle mass (sarcopenia) in older adults has led to the recognition of “osteosarcopenia” (OS) as a singular entity. Vitamin D may play important role in the manifestation of OS, in terms of intake, absorption, and bioavailability. Evidence suggests that bioavailable 25(OH)D may be a better indicator of Vitamin D compared to total 25(OH)D due to its weak bind to albumin, increasing its ‘availability’. The aim of this study was to assess total and bioavailable 25(OH)D levels in postmenopausal women and to determine their associations to bone density and muscle mass. We assessed body composition, bone density, and 25(OH)D indices of multiethnic, postmenopausal Malaysian women. A significant and negative correlation was found between body fat % and each index of 25(OH)D. Both bioavailable and total 25(OH)D were positively correlated with serum calcium and negatively correlated with iPTH(intact parathyroid hormone). VDBP(Vitamin D binding protein) level was significantly correlated with bioavailable 25(OH)D level, but not with the total 25(OH)D level. Stepwise regression analysis revealed that bioavailable, but not total, 25(OH)D was significantly correlated to bone density and muscle mass, (where stronger correlation was found with bone density), suggesting its superiority. Nevertheless, the low effect size warrants further studies.

Comparison of Vitamin D Levels, Bone Metabolic Marker Levels, and Bone Mineral Density among Patients with Thyroid Disease: A Cross-Sectional Study

Thyroid hormones have a catabolic effect on bone homeostasis. Hence, this study aimed to evaluate serum vitamin D, calcium, and phosphate and bone marker levels and bone mineral density (BMD) among patients with different thyroid diseases. This cross-sectional study included patients with underlying thyroid diseases (n = 64, hyperthyroid; n = 53 euthyroid; n = 18, hypothyroid) and healthy controls (n = 64). BMD was assessed using z-score and left hip and lumbar bone density (g/cm²). The results showed that the mean serum vitamin D Levels of all groups was low (<50 nmol/L). Thyroid patients had higher serum vitamin D levels than healthy controls. All groups had normal serum calcium and phosphate levels. The carboxy terminal collagen crosslink and procollagen type I N-terminal propeptide levels were high in hyperthyroid patients and low in hypothyroid patients. The z-score for hip and spine did not significantly differ between thyroid patients and control groups. The hip bone density was remarkably low in the hyperthyroid group. In conclusion, this study showed no correlation between serum 25(OH)D levels and thyroid diseases. The bone markers showed a difference between thyroid groups with no significant difference in BMD.

Associations of vitamin D with novel and traditional anthropometric indices according to age and sex: a cross-sectional study in central southern China

PURPOSE

Vitamin D insufficiency and obesity are recognized as worldwide concerns and have been linked with each other. New anthropometric indices reflect visceral obesity better than traditional anthropometric indices. Our aim was to identify the specific correlations of novel and traditional anthropometric indices with 25-hydroxyvitamin D (25(OH)D) concentrations by sex and age.

METHODS

Cross-sectional data on sociodemographic characteristics, lifestyle factors, clinical characteristics and biochemical measurements were collected for 12,617 Chinese adults. Four traditional anthropometric indices, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR), and two novel anthropometric indices, body roundness index (BRI) and body shape index (ABSI), were calculated.

RESULTS

In both sexes, the mean values of BMI, WC, WHtR and BRI tended to increase with 25(OH)D insufficiency, regardless of adjustment (all P < 0.05). Males with insufficient 25(OH)D had increased odds of obesity (assessed by BMI, WC, WHtR, BRI and ABSI) compared to the odds of males with sufficient 25(OH)D. Females with insufficient 25(OH)D had a higher chance of general obesity (assessed by BMI). Low 25(OH)D status was associated with indicators of obesity only in participants aged 45-64 years in both sexes.

CONCLUSION

A inverse association between obesity and lower vitamin D levels was found. Moreover, in addition to BMI, novel indicators of visceral adiposity, such as BRI and ABSI, were associated with lower 25(OH)D serum concentrations in males. The effects of optimizing vitamin D levels in obese Chinese adults need further examination, particularly in middle-aged males.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Association of 25-hydroxyvitamin D levels and metabolic syndrome in Thai postmenopausal women

BACKGROUND AND AIMS

Low serum 25-hydroxyvitamin D [25(OH)D] levels have been reported to be associated with metabolic syndrome (MetS). In this study, we aimed to investigate the association between serum 25(OH)D levels and MetS in Thai postmenopausal women.

METHODS

A total of 340 postmenopausal women were enrolled in the study. The concentration of 25(OH)D, lipid profiles, fasting blood glucose (FBG) levels, blood pressure, and demographic and anthropometric parameters were measured. Subjects were divided into the hypovitaminosis D and vitamin D sufficiency groups. The association of serum 25(OH)D levels with MetS in postmenopausal women was analyzed using multivariate regression analysis.

RESULTS

Waist circumference, total cholesterol levels, and triglyceride levels were significantly higher in hypovitaminosis D than in vitamin D sufficiency (p < 0.05). The prevalence of MetS, central obesity, and hypertriglyceridemia in hypovitaminosis D was significantly higher than in vitamin D sufficiency (p < 0.05). In the multivariable logistic regression model, hypovitaminosis D was associated with MetS (OR 1.85; 95% CI 1.12-3.04, p = 0.015), central obesity (OR 2.41; 95% CI 1.20-4.85, p = 0.014), and hypertriglyceridemia (OR 1.91; 95% CI 1.12-3.26, p = 0.018) compared with vitamin D sufficiency after adjusting for covariates. Serum vitamin D concentrations were significantly lower in the MetS group than in the non-MetS group (p = 0.016) and decreased with an increasing number of MetS components (p for trend = 0.034).

CONCLUSIONS

Hypovitaminosis D was associated with an increased risk of MetS, central obesity, and hypertriglyceridemia in Thai postmenopausal women.

Nutritional Biomarkers and Associated Factors in Community-Dwelling Older Adults: Findings from the SHIELD Study

Aging is associated with intrinsic and extrinsic changes which affect the nutrient intake and nutritional status of an older individual. Suboptimal nutritional status is linked with adverse health outcomes. There are limited data in this area for community-dwelling older adults who are not at risk of malnutrition. The objective of this study was to describe the nutritional biomarkers in 400 community-dwelling older adults (aged ≥65 years) with normal nutritional status (Malnutrition Universal Screening Test score of 0) in Singapore and to identify factors associated with these biomarkers. The majority of the participants had normal levels of pre-albumin, albumin, total protein, creatinine, zinc, corrected calcium, vitamin B12, ferritin and hemoglobin. Females had significantly higher levels of corrected calcium and vitamin B12 than males, whereas males had significantly higher levels of pre-albumin, albumin, creatinine, serum ferritin, 25-hydroxyvitamin D (25(OH)D) and hemoglobin than females. About half of the participants (52%) had low level of 25(OH)D (<30 μg/L) and 10% had low zinc level (<724 μg/L). Among those with low level of 25(OH)D, 74% had 25(OH)D insufficiency (20–<30 μg/L) and 26% had 25(OH)D deficiency (<20 μg/L). Younger age, female gender, non-Chinese ethnicity and no intake of vitamin D supplement were associated with lower serum 25(OH)D level, whereas higher body mass index (BMI) was associated with low zinc level. These findings highlight the problem of hidden nutritional insufficiencies can be missed in seemingly normal nourished community-dwelling older adults.

The influence of maternal vitamin D supplementation on infant vitamin D status: A systematic review and meta-analyses

BACKGROUND

Inconsistencies exist with regard to effect of maternal vitamin D supplementation on infant vitamin D status. The inconsistencies could be attributed to numerous factors, such as duration of intervention and dosage, among others. In this work, we conducted a systematic review and meta-analysis to determine the influence of maternal vitamin D supplementation on infant vitamin D status.

METHODS

A comprehensive systematic search was performed in Scopus, EMBASE, Web of Science, and PubMed/MEDLINE, by investigators, from database inception until November 2019, without using any restrictions. Weighted mean difference (WMD) with the 95 % CI was used for assessing the effects of maternal vitamin D supplementation on 25(OH) D levels in infants.

RESULTS

Overall results from 14 studies revealed a non-significant effect of maternal vitamin D administration on the level of 25(OH) D in breastfeeding infants (WMD: -0.464 ng/mL, 95 % CI: -6.68 to 5.75, p = 0.884, I² = 98 %). Subgroup analyses demonstrated that vitamin D supplementation dosage ≥2000 IU/day (WMD: 9 ng/mL, 95 % CI: 8.19, 9.82, I² = 99 %) and intervention duration ≥20 weeks (WMD: 16.20 ng/mL, 95 % CI: 14.89, 17.50, I² = 99 %) significantly increased 25(OH) D.

CONCLUSIONS

The main results indicate a non-significant increase in infant vitamin D following maternal vitamin D supplementation. Additionally, vitamin D supplementation dosage ≥2000 IU/day and intervention duration ≥20 weeks significantly increased infant 25(OH) D.

The effects of vitamin D and curcuminoids supplementation on anthropometric measurements and blood pressure in type 2 diabetic patients with coexisting hypovitaminosis D: A double-blind, placebo-controlled randomized clinical trial

BACKGROUND AND AIMS

Curcuminoids and vitamin D have been shown to improve blood pressure and body weight in diabetic animals; however, consistent findings in type 2 diabetes mellitus (T2DM) patients are limited. This study was performed to evaluate the effects of curcuminoids and vitamin D, simultaneously or singly on anthropometric measurements and blood pressure in T2DM patients with insufficient vitamin D level.

METHODS

In this randomized, placebo-controlled clinical trial, eighty T2DM patients were randomly assigned into 4 groups receiving (1) 500 mg/day curcuminoids; (2) 50,000 IU/week vitamin D₃; (3) 50,000 IU/week vitamin D₃ plus 500 mg/d curcuminoids; or (4) placebos for 12 weeks. Blood pressure and anthropometric measurements were evaluated before and after intervention.

RESULTS

Intergroup comparisons showed that Vitamin D (main effect) significantly reduced systolic blood pressure (SBP) and diastolic blood pressure (DBP) (P = 0/000). Curcuminoids (main effect) significantly reduced DBP (P = 0/001). Interaction effects showed that curcuminoids significantly prevented the effect of vitamin D on the reduction of SBP (P = 0.006). Whereas, vitamin D and curcuminoids had a synergistic effect on DBP reduction (P = 0.006). The comparison of changes in anthropometric measurements between the four groups showed no significant differences in the raw and adjusted models. In-group comparisons showed that SBP, DBP, waist to hip circumference (WHR), body fat mass (BFM), percent body fat (PBF) and visceral fat area (VFA) values were significantly reduced in all groups except the placebo group compared to baseline values. Only in the CR-D group, there was a significant reduction in body weight (P = 0/047).

CONCLUSIONS

Curcuminoids and vitamin D may have beneficial effects on blood pressure and anthropometric measurements in T2DM patients. CLINICAL REGISTRATION: http://www.IRCT.ir:IRCT2017041213678N22.

Associations of Serum 25-Hydroxyvitamin D with Adiposity and At-Risk Lipid Profile Differ for Indigenous (Orang Asli) Male and Female Adults of Peninsular Malaysia

BACKGROUND

Low vitamin D status, adiposity, and at-risk lipid profile are associated with adverse health consequences. This study aimed to assess serum 25(OH)D concentration of Indigenous (Orang Asli) adults and to determine the associations between serum 25(OH)D with adiposity and lipid profile, respectively.

METHODS

This cross-sectional study was conducted among 555 (164 men, 391 women) Orang Asli adults aged 18-65 years of Jah Hut sub-tribe in Krau Wildlife Reserve (KWR), Peninsular Malaysia. Demographic and socio-economic information were obtained using interviewer-administered questionnaire. Participants were also assessed for serum 25-hydroxyvitamin D (25(OH)D) concentration, adiposity indices (BMI, WC, WHtR, WHR, %BF) and lipid parameters (TC, LDL-C, HDL-C, TG). Data were analyzed using binary logistic regression via SPSS.

RESULTS

The prevalence of suboptimal 25(OH)D concentration was 26.3%, comprising 24.9% insufficiency (50 to <75 nmol/L) and 1.4% deficiency (<50 nmol/L). While men (14-30.5%) were associated with a more proatherogenic lipid profile than women (6.1-14.3%), more women were with central obesity (M: 19.5-46.3%; F: 34.5-49.1%) and suboptimal (<75 nmol/L) vitamin D status (M: 11.6%; F: 32.4%). While suboptimal 25(OH)D concentration was significantly associated with higher odds of at-risk LDL-C (p < 0.01) and obesity (WC, WHtR) (p < 0.05) in men, no significant association was observed for women. Nonetheless, it should be noted that there were only 19 men with suboptimal (<75 nmol/L) vitamin D status.

CONCLUSIONS

While suboptimal vitamin D status was relatively low in Orang Asli adults, the prevalence of obesity and undesirable serum lipids were relatively high. The sex-specific associations between vitamin D status with adiposity indices and serum lipids warrant further investigation.

Prevalence of Vitamin D Deficiency and Its Associated Work-Related Factors among Indoor Workers in a Multi-Ethnic Southeast Asian Country

Little is known about the effect of working conditions on vitamin D status in Southeast Asia, where vitamin D deficiency is common despite the presence of sunlight all year round in most places. We examined the prevalence of vitamin D deficiency and its associated work-related factors among indoor workers using the data of 213 participants (aged ≥21 years) from a workplace cohort study in Singapore. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D (25(OH)D) concentration <50 nmol/L. Data on work-related factors, socio-demographic characteristics, and lifestyle habits were collected using standardized questionnaires. Clinical and biochemical measurements were performed using standard tools and protocols. Multivariate Poisson regression was used to examine the independent association of work-related factors with vitamin D deficiency. Mean serum 25(OH)D concentration was 59.6 nmol/L. The prevalence of vitamin D deficiency was 32.9% (95% confidence interval (CI): 26.6-39.6%). In the multivariate analysis, office workers (prevalence ratio (PR): 2.16, 95% CI: 1.12-4.16 versus control room workers), workshop workers (PR: 2.25, 95% CI: 1.05-4.81 versus control room workers), and night shift workers (PR: 1.31, 95% CI: 1.03-1.67) were at a greater risk for vitamin D deficiency. Workplace policies and wellness programs should encourage workers to take regular breaks to go outdoors for sunlight exposure and to consume adequate amounts of vitamin D-rich foods to maintain optimal vitamin D levels.

Knowledge, Attitude and Practice Related to Vitamin D and Its Relationship with Vitamin D Status among Malay Female Office Workers

This study assessed knowledge, attitude and practice (KAP) related to vitamin D and its relationship with vitamin D status among Malay female office workers. A total of 147 women aged between 20 and 55 years were recruited from a university in Kuala Lumpur. They answered questionnaires related to KAP on vitamin D, sun exposure, dietary vitamin D intake and physical activity. Serum 25-hydroxyvitamin D (25OHD) was analysed using an enzyme-linked immunoassay. Nearly half (45%) of the subjects had good knowledge but moderate attitude (76%) and practice (84%) towards sunlight exposure and dietary vitamin D intake. Median serum 25OHD was 34.1 nmol/L with the majority (91%) had vitamin D insufficiency (25OHD < 50 nmol/L). Knowledge was weakly associated with attitude (r = 0.29, p < 0.001) but no association was found between knowledge and practice (r = 0.08, p = 0.355) nor attitude and practice (r = -0.001, p = 0.994). Serum 25OHD was positively associated with sunlight exposure (r = 0.22, p = 0.008) and dietary vitamin D intake (r = 0.37, p < 0.001). It can be implied that this group is at increased risk of low bone health status, which highlights the needs of public health campaigns to improve their vitamin D status.

Salivary uric acid is a predictive marker of body fat percentage in adolescents

As saliva showed to be a noninvasive source of markers useful to monitor clinical status, the hypothesis tested was that saliva may provide reliable markers able to predict the body fat accumulation in young subjects. The salivary characteristics of 248 adolescent scholars (119 girls; 14-17 years) of flow rate, pH, phosphorus, urea, and calcium concentrations were assessed in stimulated saliva (colorimetric automated technique). The concentrations of cholesterol, 7-ketocholesterol, 25-hydroxyvitamin D2 and D3, and uric acid (UA) were measured with high-performance liquid chromatography in saliva collected at home (12-hour fast). Physical examination included height, weight, and body fat percentage (%BF) measured using bioelectric impedance to classify groups in below/above the %BF cutoff. Data were evaluated using 2-way analysis of variance and multiple linear regression. No significant difference was found in the levels of 25-hydroxyvitamin D2 and D3, cholesterol, 7-ketocholesterol, phosphorus, calcium, and urea between groups above and below %BF cutoff, and the variation in salivary flow was small. Significant sex and group effects were observed for salivary UA, which was increased in adolecents with higher %BF and in males (compared to females), without sex group interaction (power = 99.8%). Sex showed a significant effect on salivary urea, with lower levels in females. A predictive model was obtained, with salivary UA and sex explaining the variation of %BF (P < .001; power = 84%). Salivary UA showed to be an important marker of body fat accumulation in adolescents, demonstrating the clinical relevance of saliva to detect early changes and to monitor the nutritional status using a noninvasive and accurate method.

Analysis of Internet searches using Google Trends to measure interest in sun protection and skin cancer in selected South-East Asian populations

BACKGROUND

Analysis of Internet search trends has been performed to evaluate interest in sun protection, artificial tanning, and skin cancers among the public, particularly in Western countries. This observational study aimed to investigate the relative popularity of search terms relating to sun protection, sunburn, skin cancers, and tanning used in Google Trends® in three South-East Asian countries (Malaysia, Singapore, and Indonesia).

METHODS

The relevant search terms were queried using the Google Trends® in each location and worldwide. The search volume indices were compared between locations and over a time period from January 1, 2004, to January 31, 2019. Correlations between "sunblock" and "sunburn" as well as "sunblock" and search terms relating to skin cancers ("skin cancer," "melanoma," "basal cell carcinoma," and "squamous cell carcinoma") were evaluated.

RESULTS

The favored search term relating to sun protection in this region was "sunblock" despite the term itself being a misnomer. The relative popularity of searches for "sunblock" also showed an increase over time and was generally higher compared with interest in sunburn, skin cancers, and artificial tanning practices. Positive correlations were noted between "sunblock" and "sunburn" in Malaysia and "sunblock" and "melanoma" in Singapore.

CONCLUSION

Insights into search trends may assist public health promotion to raise awareness regarding sun protection and skin cancers in the region by targeting commonly used terms for each geographical location.

Body Mass Index, Vitamin D, and Type 2 Diabetes: A Systematic Review and Meta-Analysis

The deficiency of vitamin D is prevalent all over the world. Studies have shown that vitamin D may play an important role in the development of obesity. The current study was conducted to quantitatively evaluate the association between serum 25-(OH) vitamin D levels and the risk of obesity in both diabetic and non-diabetic subjects. A systematic review and meta-analysis of observational studies was carried out for that purpose. We searched the Medline, PubMed, and Embase databases throughout all of March 2018. A total of fifty five observational studies for both diabetic and non-diabetic subjects were finally included in the meta-analysis. The data were analyzed by comprehensive meta-analysis software version 3 and the random effects model was used to analyze the data. The meta-analysis showed an overall inverse relationship between serum vitamin D status and body mass index (BMI) in studies of both diabetic (r = −0.173, 95% = −0.241 to −0.103, p = 0.000) and non-diabetic (r = −0.152, 95% = −0.187 to −0.116, p = 0.000) subjects. The evidence of publication bias was not found in this meta-analysis. In conclusion, the deficiency of vitamin D is associated with an increased level of BMI in the studies of both diabetic and non-diabetic subjects. Reliable evidence from well-designed future randomized controlled trials is required to confirm the findings from observational studies and to find out the potential regulatory effects of vitamin D supplementation to lower BMI.

Effect of Vitamin D Supplementation on Weight Loss, Glycemic Indices, and Lipid Profile in Obese and Overweight Women: A Clinical Trial Study

Introduction

Vitamin D (vit D) deficiency has defined as a health problem worldwide. World Health Organization (WHO) has declared that obesity is an epidemic of the 21^st century. Previous studies have shown that obesity may increase the risk of Vit D deficiency. Furthermore, other studies have demonstrated that vit D insufficiency was accompanied with higher risk of type 2 diabetes, cardiovascular diseases, hypertension, and obesity. The aim of this study was to survey the effect of vit D supplementation on weight loss among overweight and obese women aged 20-40 years in Isfahan.

Methods

This double-blind clinical trial was done on 50 overweight and obese women who were divided into two groups, in which one group received vit D supplements and the other group received placebo. Intervention group received vit D with dozes 50,000 IU/w for 6 weeks. The levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), fasting blood sugar (FBS), insulin (ins), homeostasis model assessment of ins resistance (IR), C-reactive protein (CRP), height, weight (WT), waist circumference (WC), hip circumference (HC), and blood pressure (BP) were measured before and after intervention.

Results

After using vit D supplementation for 6 weeks, WT, WC, and body mass index (BMI) were decreased significantly and serum vit D increased significantly compared to control group (P < 0.001). Other factors including TC, TG, LDL-c, HDL-c, FBS, CRP, ins, IR, and waist to hip ratio (WHR) did not change significantly (P > 0.05).

Conclusions

After 6 weeks of intervention, the means of WT, BMI, WC, and HC decreased significantly. Previous studies have shown that vit D deficiency was more prevalence in obese people and there was an inverse association among vit D with BMI and WC. The relationship between vit D and lipid profiles such as glycemic indexes, anthropometric indexes, CRP, and BP is not clear and needs more study in the future.

Vitamin D status in adult patients with nonmelanoma skin cancer in Cape Town, South Africa: a cross-sectional study

BACKGROUND

Ultraviolet (UV) radiation is the most important environmental risk factor for the development of nonmelanoma skin cancer (NMSC). UV radiation is, however, also vital in the formation of vitamin D in humans. Strict sun protection advised to skin cancer patients may lead to vitamin D deficiency, yet vitamin D may have a protective effect against cancer formation.

OBJECTIVES

The primary aim was to determine whether patients with nonmelanoma skin cancer at our institution were vitamin D deficient.

METHODS

25-Hydroxyvitamin D (25[OH]D) levels were determined in 109 patients with a diagnosis of basal cell carcinoma (BCC) and/or squamous cell carcinoma (SCC) during the summer and winter of 2015 at the Tygerberg Academic Hospital in Cape Town, South Africa. Associations between clinical and epidemiological data and the 25(OH)D level results were investigated. Vitamin D deficiency was defined as total 25(OH)D levels <20 ng/mL (<50 nmol/L).

RESULTS

It was found that 49.5% of NMSC patients were vitamin D deficient, and 41.3% had insufficient vitamin D levels. Females were more likely than males to be vitamin D deficient (P = 0.047). Winter was significantly associated with vitamin D deficiency, compared to summer (OR = 4.81, 95%CI = 2.09-11.09, P <0.001). Having a previous SCC appeared associated with not being vitamin D deficient (OR = 0.46, 95%CI = 0.20-1.11, P = 0.084).

CONCLUSIONS

The findings highlight the need for the development of recommendations and guidelines on sun protection in patients with NMSC, while still ensuring an adequate vitamin D status. High risk factors included winter and female gender.

Review on Potential Vitamin D Mechanism with Type 2 Diabetes Mellitus Pathophysiology in Malaysia

Evidences on vitamin D deficiency suggest there is increasing risk of diabetes. To date, some cohort, observation, cross-sectional studies on populations and randomized controlled trials in vitamin D supplements highlighting the potential of vitamin D are essentially in modifying Type 2 Diabetes Mellitus (T2DM) pathophysiology. Relevant literature sought in a various databases focus on the discovery of vitamin D studies in Malaysia, particularly in dietary, health status and disease study. However, recent data in Malaysia, the scope of the literature focuses on the deficient vitamin D mediated insulin impairment. The development of literary findings encompasses on the etiology of diabetes which highly correlates with decreased mechanism of action of vitamin D. It is important to understand diabetes etiology before explaining more about insulin resistance mechanisms which is strongly correlated with the involvement of c-Jun N-terminal kinase (JNK) pathways in insulin signalling. Furthermore, the vitamin D works synergistically with calcium homeostasis which is believed to have interaction with insulin. The purpose of this article is to illustrate the potential of vitamin D in modulating T2DM pathophysiology. Existing evidence showing the biochemical function of vitamin D is strongly involved in the pathogenesis of T2DM which requires considerable attention.

Nonalcoholic Fatty Liver Disease and Abdominal Fat Accumulation According to Vitamin D Status in Patients with Type 2 Diabetes

Background

Vitamin D deficiency is known to increase the incidence of metabolic syndrome. Nonalcoholic fatty liver disease is a common metabolic disease in patients with type 2 diabetes. This study evaluated nonalcoholic fatty liver disease and abdominal fat accumulation according to 25-hydroxyvitamin D status in patients with type 2 diabetes.

Methods

The study comprised 302 patients with type 2 diabetes. Patients were divided into three groups based upon their 25-hydroxyvitamin D status: vitamin D deficient group (<10 ng/mL), vitamin D insufficient group (≥10 to <20 ng/mL) and vitamin D sufficient group (≥20 ng/mL). Patient clinical and laboratory markers were evaluated retrospectively.

Results

Visceral fat thickness was significantly higher in the vitamin D deficient group. There were no differences in glycemic control, body mass index, and subcutaneous fat thickness correlated with 25-hydroxyvitamin D status. The prevalence of nonalcoholic fatty liver disease was significantly higher in the vitamin D deficient group compared to the vitamin D sufficient and vitamin D insufficient groups. In multivariate logistic analysis, after adjustment for age, sex, body mass index, glycated hemoglobin and homeostasis model assessment of insulin resistance, patients with type 2 diabetes in the vitamin D sufficient group showed significantly lower odds ratio for nonalcoholic fatty liver disease than those within the vitamin D deficient group.

Conclusion

In type 2 diabetes, the vitamin D deficient group showed thicker visceral fat thickness and higher nonalcoholic fatty liver disease prevalence.

Vitamin D Status and Its Associated Risk Factors among Adults in the Southwest Region of Cameroon

Background

Vitamin D has been shown to exert its actions on the musculoskeletal, gastrointestinal, prostate, renal, endocrine, immune, and cardiovascular systems. Current reported data of hypovitaminosis D reveals a global pandemic, with an estimated one billion people worldwide presenting with hypovitaminosis D.

Objective

This study aimed at investigating the vitamin D status and its associated risk factors in Cameroonians from the South West Region.

Method

The study was a community- and hospital-based prospective longitudinal study. It was carried out during the dry and rainy seasons between the months of July and December 2015 in the South West Region of Cameroon involving 372 participants aged 35 years and above. After obtaining informed consent, a structured questionnaire was used to capture demographic data and risk factors of vitamin D deficiency. Blood samples were collected from the volunteer participants in the peak months of the rainy season and dry season, and the serum used to analyse for vitamin D by ELISA and calcium by spectrophotometry. 25(OH)D levels ≥75 nmol/L (≥30 ng/mL) were considered sufficient while levels <75 nmol/L were considered as hypovitaminosis D (insufficiency/deficiency).

Results

Hypovitaminosis D (deficiency/insufficiency) was prevalent in 25.8% (96) of the study population, with only 3.2% (12) deficiency and 22.6% (84) insufficiency. There was a significant inverse relationship (r=−0.119, p=0.02) between age and 25(OH)D levels; however, this relationship was not significant when controlled for gender, number of hours spent outdoors, and percentage of body covered. Gender, ethnic origin, percentage of body covered, time spent outdoors, and season did not influence serum vitamin D levels.

Conclusion

Results of this study suggest that the prevalence of hypovitaminosis D is relatively low in this study population and only age is a risk factor of vitamin D deficiency.

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

BACKGROUND

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

AIM

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

SUBJECTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparing palm oil tocotrienol rich fraction with α-tocopherol supplementation on oxidative stress in healthy older adults

Vitamin E is a fat-soluble compound and powerful antioxidant that have been shown to protect the cell membranes against damage caused by free radicals. Human vitamin E supplementation studies are usually limited to α-tocopherol but currently tocotrienols are also available. This study aims to compare the effects of tocotrienol rich fraction (TRF) with α-tocopherol (α-TF) supplementation on oxidative stress in healthy male and female older adults aged 50-55 years old. A total of 71 subjects both male and female aged between 50 and 55 years were divided into groups receiving placebo (n = 23), α-TF (n = 24) and TRF (n = 24) for six months. Blood was taken at baseline (month 0), 3 months and 6 months osf supplementation for determination of plasma malondialdehyde (MDA), protein carbonyl, total DNA damage, vitamin D concentration and vitamin E isomers. α-TF supplementation reduced plasma MDA and protein carbonyl in female subjects after 3 and 6 months. TRF supplementation reduced MDA levels in both males and females as early as 3 months while DNA damage was reduced in females only at 6 months. Supplementation with α-TF and TRF increased plasma vitamin D concentration in both males and females after 6 months, but vitamin D concentration in male subjects were significantly higher compared to female subjects in TRF group. Vitamin E isomer determination showed α-TF, α-tocotrienol and γ-tocotrienol were increased in both male and female subjects. In conclusion, TRF supplementation effects were different from α-TF in reducing oxidative stress markers and vitamin D levels with a more pronounced effect in female subjects.

Prevalence of vitamin D deficiency and association with metabolic syndrome in a Qatari population

OBJECTIVES

Despite long hours of sunlight in Qatar and other regions of the Middle East, vitamin D deficiency has been rising. In parallel, the prevalence of metabolic syndrome has also been increasing in Qatar. Vitamin D levels have been associated with metabolic syndrome but the data are inconsistent and no studies have addressed these inter-relationships in a Middle Eastern population where the prevalence of these conditions is high. The objective is to investigate the prevalence of vitamin D deficiency and its association with metabolic syndrome and its components in the Qatar Biobank population.

METHODS

A cross-sectional study of 1205 participants (702 women and 503 men) from the Qatar Biobank, comprising Qataris and non-Qataris between the ages of 18 and 80 years, was used to perform multivariate linear regression analyses to examine the association between metabolic syndrome and prevalence of vitamin D deficiency (defined as <20 ng ml-1 serum vitamin D levels) adjusting for age, sex, ethnicity, season of blood collection, physical activity and education. Odds ratios and 95% confidence intervals were calculated for all analyses.

RESULTS

Approximately 64% of participants were vitamin D deficient (<20 ng ml-1) with more men being deficient (68.6%) than women (61.3%). Serum vitamin D was 8% lower in individuals with metabolic syndrome (RR: 0.92, 95%CI: 0.87-0.98, P-value: 0.01) compared to individuals without metabolic syndrome. Waist circumference and HDL as well as high triglyceride levels were also significantly positively associated with vitamin D deficiency. No association was found between the other components of metabolic syndrome or diabetes and the presence of vitamin D deficiency.

CONCLUSIONS

Vitamin D deficiency is prevalent in this Qatari population. Presence of metabolic syndrome was associated with presence of vitamin D deficiency. Future prospective studies need to be conducted to investigate the potential for causality.

Association of serum 25-hydroxyvitamin D3 with adipokines and inflammatory marker in persons with prediabetes mellitus

BACKGROUND

The association of vitamin D status and inflammation prediabetes mellitus (PreDM) individuals has not been investigated. We investigated the association of serum 25-hydroxyvitamin D₃ (25(OH) D₃) with adipokines and inflammatory markers in persons with PreDM.

METHODS

In this cross-sectional study, we stratified 418 nondiabetic subjects as having PreDM or normal fasting glucose (NFG), and divided PreDM or NFG subjects into vitamin D sufficient, vitamin D insufficient and vitamin D deficient subgroups. 25(OH) D₃ concentrations were determined by HPLC. Serum tumor necrosis factor-α (TNF-α), interleiukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP), adiponectin, leptin and resistin were measured by ELISA.

RESULTS

In the PreDM group, compared with those in the vitamin D sufficient subgroup, vitamin D insufficient subgroup and vitamin D deficient subgroup had higher concentrations of hs-CRP and leptin (P<0.05). In the PreDM-deficient or PreDM-insufficient subgroup, mean hs-CRP and leptin concentration was higher than in the PreDM-sufficient, NFG-deficient, NFG-insufficient and NFG-sufficient subgroups (P<0.05). Serum 25(OH) D₃ concentrations were inversely associated with hs-CRP and leptin concentrations after adjusted the BMI only in the PreDM group (P<0.05). At the multivariate analysis, hs-CRP and leptin were the major determinant of 25(OH) D₃ concentration (β=-0.174 and β=-0.171, respectively).

CONCLUSIONS

25(OH) D₃ status in PreDM individuals was inversely correlated with concentrations of hs-CRP and leptin, suggesting their involvement in the inflammation response between vitamin D status and PreDM.

Association between serum levels of bioavailable vitamin D and negative symptoms in first-episode psychosis

Total vitamin D levels had been commonly reported to be lowered in patients with chronic psychotic illnesses in countries from the higher latitudes. However, studies on patients with first episode psychosis (FEP) are limited. In this study we investigated serum concentrations of total and bioavailable vitamin D levels in FEP patients compared to healthy controls and the association between symptom severity and vitamin D components. A total of 31 FEP patients and 31 healthy controls were recruited from Institute of Mental Health, Singapore. FEP patients were identified using Structured Clinical Interview for DSM-IV Axis I disorders (SCID-1) and severity symptoms were assessed using the positive and negative syndrome scale (PANSS). Sera from participants were analyzed for total vitamin D, vitamin D-binding protein (DBP) and bioavailable vitamin D. Linear regressions were performed to examine the associations between serum total and bioavailable vitamin D and the PANSS subscales. Current study noted a significantly lower bioavailable vitamin D was in the FEP group and an association between bioavailable vitamin D and negative symptoms in FEP patients in a population with a consistent supply of sun exposure throughout the year.

The association between gender difference with metabolic syndrome, metabolic syndrome score and serum vitamin D levels in Korean adults

This study assessed the association between gender difference with metabolic syndrome (MetS), metabolic syndrome score (MSS) and serum vitamin D levels in Korean adults. Analyses were restricted to 5147 adults (2162 men; 2985 women) aged 20 and older, using the 2012 Korean National Health and Nutrition Examination Survey (KNHANES) data. In the non-adjusted model, serum 25-hydroxyvitamin D [25(OH)D] levels were inversely associated with MetS (p = .001) and MSS (p = .009) in men, but positively associated with MetS (p = .002) and MSS (p < .001) in women. However, when adjusted for related variables (including age), serum 25(OH)D levels were inversely associated with MetS (p < .001) and MSS (p < .001) in men, but were not associated with MetS (p = .200) and MSS (p = .541) in women. In conclusion, increases in MetS and its components were inversely associated with the serum vitamin D concentration in men.

Vitamin D deficiency in Malaysian adolescents aged 13 years: findings from the Malaysian Health and Adolescents Longitudinal Research Team study (MyHeARTs)

OBJECTIVE

To determine the prevalence of vitamin D deficiency (<37.5 nmol/L) among young adolescents in Malaysia and its association with demographic characteristics, anthropometric measures and physical activity.

DESIGN

This is a cross-sectional study among Form 1 (year 7) students from 15 schools selected using a stratified random sampling design. Information regarding sociodemographic characteristics, clinical data and environmental factors was collected and blood samples were taken for total vitamin D. Descriptive and multivariable logistic regression was performed on the data.

SETTING

National secondary schools in Peninsular Malaysia.

PARTICIPANTS

1361 students (mean age 12.9±0.3 years) (61.4% girls) completed the consent forms and participated in this study. Students with a chronic health condition and/or who could not understand the questionnaires due to lack of literacy were excluded.

MAIN OUTCOME MEASURES

Vitamin D status was determined through measurement of sera 25-hydroxyvitamin D (25(OH)D). Body mass index (BMI) was classified according to International Obesity Task Force (IOTF) criteria. Self-reported physical activity levels were assessed using the validated Malay version of the Physical Activity Questionnaire for Older Children (PAQ-C).

RESULTS

Deficiency in vitamin D was seen in 78.9% of the participants. The deficiency was significantly higher in girls (92.6%, p<0.001), Indian adolescents (88.6%, p<0.001) and urban-living adolescents (88.8%, p<0.001). Females (OR=8.98; 95% CI 6.48 to 12.45), adolescents with wider waist circumference (OR=2.64; 95% CI 1.65 to 4.25) and in urban areas had higher risks (OR=3.57; 95% CI 2.54 to 5.02) of being vitamin D deficient.

CONCLUSIONS

The study shows a high prevalence of vitamin D deficiency among young adolescents. Main risk factors are gender, ethnicity, place of residence and obesity.

High levels of serum vitamin D are associated with a decreased risk of metabolic diseases in both men and women, but an increased risk for coronary artery calcification in Korean men

Background

There are conflicting results for relationships between serum vitamin D levels and metabolic diseases. The aim of this study was to investigate whether serum vitamin D levels were associated with various metabolic diseases including insulin resistance (IR), metabolic syndrome (MS), fatty liver (FL), and coronary artery calcification (CAC), along with assessing gender differences for these relationships in Korean adults.

Methods

A total of 180,918 subjects (98,412 men and 82,506 women) who participated in a comprehensive health examination in the 2012–2013 period at Kangbuk Samsung Hospital, College of Medicine, Sungkyunkwan University were included. Serum vitamin D and metabolic markers were analyzed and CAC was estimated. Subjects were divided according to quartile groups of serum vitamin D. To examine the relationships of serum vitamin D to metabolic diseases and metabolic factors, multivariate logistic analysis was conducted.

Results

High levels of serum vitamin D was associated with lower ORs for MS, IR and FL both in men and women (all p < 0.05). For men, ORs for CAC were significantly higher in third and the highest quartile groups for serum vitamin D in all the analyzed models (all p < 0.05). However, women showed no significant results between serum vitamin D and CAC.

Conclusions

High levels of serum vitamin D were associated with lower risk of MS, IR and FL in both Korean men and women, but were associated with higher risk of CAC only in men, and not in women.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0432-3) contains supplementary material, which is available to authorized users.

Risk factors for antenatal hypovitaminosis D in an urban district in Malaysia

Background

Pregnant women form one of the high risk groups facing hypovitaminosis D. Low level of vitamin D will affect directly or indirectly both mother and fetus. Screening vitamin D in the first trimester of pregnancy is important to determine the necessary preventive action. Therefore, this study was aimed to determine the prevalence of hypovitaminosis D and its risk factors among pregnant women in the first trimester.

Methods

A cross sectional study was carried out among first trimester pregnant women during their first antenatal visit. Samples were taken from different ethnicities in an urban district in Malaysia. A total of 396 respondents (99 % response rate) aged 18–40 years completed self–administered and guided questionnaire (characteristics and risk factors), validated semi-quantitative food frequency questionnaire for vitamin D in Malaysia (FFQ vitamin D/My), anthropometric measures (weight and height), blood test for serum 25(OH)D, skin measurement using Mexameter (MX 18) and Fitzpatrick Skin Type Chart Measurement (FSTCM). Data were analyzed to determine the association between risk factors and hypovitaminosis D.

Results

The prevalence of hypovitaminosis D (serum 25(OH)D < 50 nmol/L) was 90.4 % (358). The mean age of respondents was 28.06 ± 4.09 years old. The independent predictors of hypovitaminosis D were Malay ethnicity (OR 33.68; 95 % CI: 12.81, 88.56), Indian ethnicity (OR 16.86; 95 % CI: 3.78,75.20), secondary education (OR 12.12; 95 % CI: 2.71, 54.16) and tertiary education (OR 14.38; 95 % Cl: 3.31, 62.45).

Conclusion

Awareness should be raised among Malay and Indian pregnant women with secondary and tertiary education who consumed vitamin D (especially milk) poorly in order to prevent adverse health outcomes. Further studies need to be conducted among health care workers to determine their level of knowledge related to vitamin D, as they are front liner in detecting the hypovitaminosis D.