Differences in homeostatic model assessment (HOMA) values and insulin levels after vitamin D supplementation in healthy men: a double‐blind randomized controlled trial

Abstract

Vitamin D is thought to play a role in glucose metabolism. The aim of the present study was to determine the effect of vitamin D supplementation on markers of insulin sensitivity and inflammation in men without diabetes with vitamin D deficiency/insufficiency. In this 1-year double-blind randomized controlled trial, 130 men aged 20-65 years (mean age 47.52 ± 11.84 years) with serum 25-hydroxyvitamin D levels <50 nmol/l (mean 38.89 ± 8.64 nmol/l) were randomized to treatment (100 000 IU vitamin D bimonthly) or placebo. Anthropometric measurements, demographic questionnaires, and blood indices (fasting glucose, insulin, high-sensitivity C-reactive protein, lipids) were collected and repeated after 6 and 12 months. The compliance rate was 98.5%. Multivariate models, adjusted for baseline levels, age, body mass index, sun exposure, physical activity and LDL, showed significant differences in insulin and homeostatic model assessment of insulin resistance (HOMA-IR) values between groups. Levels of insulin and HOMA-IR values remained steady during the study period in the treatment group but increased by 16% in the control group (p = 0.038 and p = 0.048, respectively). Vitamin D supplementation administered for 12 months in healthy men maintained insulin levels and HOMA-IR values relative to the increase in the control group. Further studies are needed to establish the long-term effect of vitamin D supplementation on the risk of diabetes.

Vitamin D in the Middle East and North Africa

“…The search yielded 1280 citations after removal of duplicates. We screened the full text of 242 papers, and identified 14 relevant trials ( Shahgheibi et al, 2016 ; Vaziri et al, 2016 ; Saad et al, 2018 ; Talaat et al, 2016 ; Taheri et al, 2015 ; Tepper et al, 2016 ; Zarrin et al, 2017 ; Kamelian et al, 2017 ; Jozanikohan and Kazemi Saleh, 2015 ; Mohammad-Alizadeh-Charandabi et al, 2015 ; Shehata, 2016 ; Rahme et al, 2017 ; Mojibian et al, 2015 ; Behjat Sasan et al, 2017 ).…”

“…The current update identified 8 trials: 5 from Iran ( Taheri et al, 2015 ; Zarrin et al, 2017 ; Kamelian et al, 2017 ; Jozanikohan and Kazemi Saleh, 2015 ; Mohammad-Alizadeh-Charandabi et al, 2015 ), 1 from Egypt ( Shehata, 2016 ), one from occupied Palestine/Israel ( Tepper et al, 2016 ), and one from Lebanon ( El-Hajj Fuleihan et al, 2016 ; Rahme et al, 2017 ). The latter was included in our previous review ( Chakhtoura et al, 2017a ), since we had access to primary data, but it was not published then, and is described herein ( Table 1 ) ( El-Hajj Fuleihan et al, 2016 ; Taheri et al, 2015 ; Tepper et al, 2016 ; Zarrin et al, 2017 ; Kamelian et al, 2017 ).…”

Effects of Vitamin D Supplementation on General and Central Obesity: Results from 20 Randomized Controlled Trials Involving Apparently Healthy Populations

“…Most observational studies have confirmed that vitamin D status is inversely correlated with the BMI [7]. However, several randomized controlled trials (RCTs) and a recent meta-analysis on the effects of vitamin D supplementation on BMI did not seem to support this correlation [17][18][19][20]. On the other hand, several studies have suggested that central obesity is considered as a better predictor of several adverse health outcomes and mortality [21,22].…”

Sex-Specific Association of Serum 25-Hydroxyvitamin D₃ with Insulin Resistance in Chinese Han Patients with Newly Diagnosed Type 2 Diabetes Mellitus

“…Consistently, low vitamin D status is associated with high levels of inflammatory factors such as IL-6, TNF-a, and C-reactive protein (28)(29)(30). Remarkably, recent clinical trials have indicated that supplementation of vitamin D may reduce the risk of diabetes mellitus by attenuating the development of insulin resistance rather than by lowering insulin secretion, supporting the association of vitamin D with insulin resistance in the pathogenesis of T2DM (31).…”