Weight and skin colour as predictors of vitamin D status: results of an epidemiological investigation using nationally representative data

Rajan, Sonali; Weishaar, Tom; Keller, Bryan

doi:10.1017/s1368980016000173

Cited by 17 publications

(17 citation statements)

References 32 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As Wang et al demonstrated that vitamin D-binding protein polymorphism was associated with increased susceptibility to T2D in Asians, but not in Caucasians; this might explain the heterogeneous responses between Asians and the other groups [ 41 ]. In addition, studies found that populations with darker skin color and cultural preferences toward less exposure to the sun, which matched the profile of Middle Easterners, were at a higher risk of vitamin D deficiency, and that, in turn, was associated with better effects from supplementation [ 42 , 43 ]. However, none of the studies we included in the analysis were based on American participants’ data.…”

Section: Discussionmentioning

confidence: 99%

The Effect of Vitamin D Supplementation on Glycemic Control in Type 2 Diabetes Patients: A Systematic Review and Meta-Analysis

et al. 2018

View full text Add to dashboard Cite

Observational studies have indicated an inverse association between vitamin D levels and the risk of diabetes, yet evidence from population interventions remains inconsistent. PubMed, EMBASE, Cochrane Library and ClinicalTrials.gov were searched up to September 2017. Data from studies regarding serum 25(OH)D, fasting blood glucose (FBG), hemoglobin A1c (HbA1c), fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were pooled. Twenty studies (n = 2703) were included in the meta-analysis. Vitamin D supplementation resulted in a significant improvement in serum 25(OH)D levels (weighted mean difference (WMD) = 33.98; 95%CI: 24.60–43.37) and HOMA-IR (standardized mean difference (SMD) = −0.57; 95%CI: −1.09~−0.04), but not in other outcomes. However, preferred changes were observed in subgroups as follows: short-term (WMDFBG = −8.44; 95%CI: −12.72~−4.15), high dose (WMDFBG = −8.70; 95%CI: −12.96~−4.44), non-obese (SMDFasting insulin = −1.80; 95%CI: −2.66~−0.95), Middle Easterners (WMDFBG = −10.43; 95%CI: −14.80~−6.06), baseline vitamin D deficient individuals (WMDFBG = −5.77; 95%CI: −10.48~−1.05) and well-controlled HbA1c individuals (WMDFBG = −4.09; 95%CI: −15.44~7.27). Vitamin D supplementation was shown to increase serum 25(OH)D and reduce insulin resistance effectively. This effect was especially prominent when vitamin D was given in large doses and for a short period of time, and to patients who were non-obese, Middle Eastern, vitamin D deficient, or with optimal glycemic control at baseline.

show abstract

Section: Discussionmentioning

confidence: 99%

The Effect of Vitamin D Supplementation on Glycemic Control in Type 2 Diabetes Patients: A Systematic Review and Meta-Analysis

et al. 2018

View full text Add to dashboard Cite

show abstract

“…47 Although vitamin D deficiency is widely prevalent, individuals with darker skin color are at an increased risk of vitamin D deficiency and cultural preferences dictating that the amount of skin exposure to the sun may play a role in sunscreen use and overall vitamin D metabolism in individuals. 48,49 We did not incorporate in our analyses country latitude or season(s) during which study was conducted as indicators of overall ultraviolet light exposure. 50 Also, there were differences across the included studies with regard to the method of serum 25(OH) vitamin measurement, thus adding to the challenge of comparing the baseline vitamin D status of participants across studies.…”

Section: Discussionmentioning

confidence: 99%

The effect of vitamin D supplementation on glucose metabolism in type 2 diabetes mellitus: A systematic review and meta-analysis of intervention studies

Lee

Iyer

Liu

et al. 2017

Journal of Diabetes and its Complications

View full text Add to dashboard Cite

Aims We aimed to assess whether vitamin D supplementation improves glucose metabolism in adults with type 2 diabetes. Methods PubMed and Cochrane database were searched up to July 1st 2016 for randomized controlled trials that assessed the relationship between vitamin D supplementation and glucose metabolism (change in hemoglobin A1C (HbA1C) and fasting blood glucose (FBG)) among adults with type 2 diabetes. Results Twenty nine trials (3324 participants) were included in the systematic review. Among 22 studies included in the meta-analysis, 19 reported HbA1C, 16 reported FBG outcomes and 15 were deemed poor quality. There was a modest reduction in HbA1C (−0.32% [−0.53 to −0.10], I2 = 91.9%) compared to placebo after vitamin D supplementation but no effect on FBG (−2.33 mg/dl [−6.62 to 1.95], I2 = 59.2%). In studies achieving repletion of vitamin D deficiency (n = 7), there were greater mean reductions in HbA1C (−0.45%, [−1.09 to 0.20]) and FBG (−7.64 mg/dl [−16.25 to 0.97]) although not significant. Conclusions We found a modest reduction of HbA1C after vitamin D treatment in adults with type 2 diabetes albeit with substantial heterogeneity between studies and no difference in FBG. Larger studies are needed to further evaluate the glycemic effects of vitamin D treatment especially in patients with vitamin D deficiency.

show abstract

“…Given the novel research focus on this topic and the conflicting evidence, we sought to expand current literature by including participants highly affected by the risk of developing diabetes [9] and at the same time deficient in vitamin D. These characteristics are likely to alter the efficacy of vitamin D supplementation, since better effects of supplementation have been observed in deficient patients rather than insufficient or sufficient [21]. This is the first placebo-control trial in the Middle East in a population with that aims to investigate the effect of…”

Section: Introductionmentioning

confidence: 99%

The effect of vitamin D supplementation on the glycemic control of pre-diabetic Qatari patients in a randomized control trial

et al. 2019

View full text Add to dashboard Cite

Background: Vitamin D deficiency is associated with indicators of pre-diabetes including, insulin resistance, β-cell dysfunction and elevated plasma glucose with controversial findings from current trials. This study aims to investigate the long-term effect of vitamin D on glucose metabolism and insulin sensitivity in pre-diabetic and highly vitamindeficient subjects. Methods: One hundred thirty-two participants were randomized to 30,000 IU vitamin D weekly for 6 months. Participants underwent oral glucose tolerance test (OGTT) at 3-month intervals to determine the change in plasma glucose concentration at 2 h after 75 g OGTT (2hPCG). Secondary measurements included glycated hemoglobin, fasting plasma glucose and insulin, post-prandial insulin, indices of insulin sensitivity (HOMA-IR, Matsuda Index), β-cell function (HOMA-β, glucose and insulin area under the curve (AUC), disposition and insulinogenic indices), and lipid profile. Results: A total of 57 (vitamin D) and 75 (placebo) subjects completed the study. Mean baseline serum 25(OH) D levels were 17.0 ng/ml and 14.9 ng/ml for placebo and vitamin D group, respectively. No significant differences were observed for 2hPC glucose or insulin sensitivity indices between groups. HOMA-β significantly decreased in the vitamin D group, while area under curve for glucose and insulin showed a significant reduction in β-cell function in both groups. Additionally, HOMA-β was found to be significantly different between control and treatment group and significance persisted after adjusting for confounding factors. Conclusion: Vitamin D supplementation in a pre-diabetic and severely vitamin-deficient population had no effect on glucose tolerance or insulin sensitivity. The observed reduction in β-cell function in both placebo and vitamin D groups could be attributed to factors other than supplementation. Trial registration: NCT02098980, 28/03/2014 (www.clinicaltrials.gov).

show abstract

Weight and skin colour as predictors of vitamin D status: results of an epidemiological investigation using nationally representative data

Abstract: Vitamin D status varied predominantly by body weight and skin colour. Recommendations by nutritionists for diet and supplementation needs should take this into account if vitamin D-related health disparities are to be meaningfully reduced across the USA.

Cited by 17 publications

References 32 publications

The Effect of Vitamin D Supplementation on Glycemic Control in Type 2 Diabetes Patients: A Systematic Review and Meta-Analysis

The Effect of Vitamin D Supplementation on Glycemic Control in Type 2 Diabetes Patients: A Systematic Review and Meta-Analysis

The effect of vitamin D supplementation on glucose metabolism in type 2 diabetes mellitus: A systematic review and meta-analysis of intervention studies

The effect of vitamin D supplementation on the glycemic control of pre-diabetic Qatari patients in a randomized control trial

Contact Info

Product

Resources

About