Effects of calcium–vitamin D co-supplementation on metabolic profiles in vitamin D insufficient people with type 2 diabetes: a randomised controlled clinical trial

Abstract

ClinicalTrials.gov NCT01662193 FUNDING: Clinical Research Council, Isfahan University of Medical Sciences, Isfahan, Iran.

MANAGEMENT OF ENDOCRINE DISEASE: The effect of vitamin D supplementation on glycaemic control in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

“…The quality assessment of the studies resulted in 14 out of 23 studies having a good quality (Appendix 1, see section on Appendix given at the end of this article) (12,19,20,21,22,23,24,25,26,27,28,29,30,31). The main characteristics and main outcomes of the included studies are given in Table 1.…”

“…The main characteristics and main outcomes of the included studies are given in Table 1. All studies had a randomized controlled trial design, of which 18 studies used a placebo for control (12,19,20,22,23,24,25,27,29,30,31,32,33,34,35,36,37,38), three studies compared vitamin D fortified yoghurt versus plain yoghurt (21,28,39), one study used oral calcium supplementation for control (26), and one study used vitamin C supplementation for control (40). Apart from two studies, which solely included post-menopausal women (21,33), all studies included both men and women.…”

“…Thirteen studies reported data on insulin resistance, of which twelve studies used the HOMA-IR to quantify insulin resistance (19,20,21,22,24,25,26,29,30,35,36,39), and one study measured insulin resistance through hyperinsulinaemic-euglycaemic clamp method (23). Two studies observed a significant reduction in insulin resistance after vitamin D supplementation (21,39), and one study found a negative effect of vitamin D supplementation on insulin resistance compared with placebo (35).…”

A study to assess the effect of vitamin D supplementation on insulin resistance and glycaemic control in type 2 diabetes mellitus patients

“…The results were similar to a parallel designed randomized placebo-controlled clinical trial, conducted by Tabesh, et al which reported reduced HbA1c levels (change from baseline of -0.70 ± 0.19%, p= 0.02) with vitamin D supplementation. 28 Another crosssectional study by Bonakdaran, et al done with 119 type 2 diabetic patients showed that calcitriol therapy resulted in significant reduction in HbA1c levels (-0.8%, p=0.01). 29 Similarly, a study was done by Hamid, et al to evaluate the effect of adding vitamin D to therapeutic regimen of type 2 diabetic patients compared to placebo.…”

Long-Term Vitamin D Supplementation and the Effects on Recurrence and Metabolic Status of Cervical Intraepithelial Neoplasia Grade 2 or 3: A Randomized, Double-Blind, Placebo-Controlled Trial

“…In addition, to estimate the nutrient intakes of the participants, we used a 3-day food diary. However, the reliability and validity of 3-day food diary for Iranian adults have been previously confirmed in vitamin D supplementation studies [48-49]; but this method may not be able to capture the habitual dietary vitamin D intake, as the individual’s day-to-day variations may be high among most of the populations. In addition, we believe that hypercalcemia is a strong indication of vitamin D toxicity.…”