Jennifer C Seida1, Joanna Mitri, Isabelle N Colmers, Sumit R Majumdar, Mayer B Davidson, Alun L Edwards, David A Hanley, Anastassios G Pittas, Lisa Tjosvold, Jeffrey A Johnson. 1. Alliance for Canadian Health Outcomes Research in Diabetes (J.C.S., I.N.C., S.R.M., L.T., J.A.J.) and Division of General Internal Medicine (S.R.M.), Department of Medicine, University of Alberta, Edmonton, Alberta, Canada T6G 2E1; Division of Endocrinology, Diabetes & Metabolism, Tufts Medical Center (J.M., A.G.P.), Boston, Massachusetts 02111; Department of Medicine, Charles R. Drew University (M.B.D.), Los Angeles, California 90059; and Division of Endocrinology and Metabolism, University of Calgary (A.L.E., D.A.H.), Calgary, Canada T2N 1N4.
Abstract
CONTEXT: Observational studies report consistent associations between low vitamin D concentration and increased glycemia and risk of type 2 diabetes, but results of randomized controlled trials (RCTs) are mixed. OBJECTIVE: The objective of the study was to systematically review RCTs that report on the effects of vitamin D supplementation on glucose homeostasis or diabetes prevention. DATA SOURCES: Sources of data for the study were MEDLINE, EMBASE, SCOPUS, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Technology Assessment, and Science Citation Index from inception to June 2013. STUDY SELECTION: Study selection was trials that compared vitamin D3 supplementation with placebo or a non-vitamin D supplement in adults with normal glucose tolerance, prediabetes, or type 2 diabetes. DATA EXTRACTION AND SYNTHESIS: Two reviewers collected data and assessed trial quality using the Cochrane Risk of Bias tool. Random-effects models were used to estimate mean differences (MDs) and odds ratios. The main outcomes of interest were homeostasis model assessment of insulin resistance, homeostasis model assessment of β-cell function, hemoglobin A1c levels, fasting blood glucose, incident diabetes, and adverse events. DATA SYNTHESIS: Thirty-five trials (43 407 patients) with variable risk of bias were included. Vitamin D had no significant effects on insulin resistance [homeostasis model assessment of insulin resistance: MD -0.04; 95% confidence interval (CI) -0.30 to 0.22, I-squared statistic (I(2)) = 45%], insulin secretion (homeostasis model of β-cell function: MD 1.64; 95% CI -25.94 to 29.22, I(2) = 40%), or hemoglobin A1c (MD -0.05%; 95% CI -0.12 to 0.03, I(2) = 55%) compared with controls. Four RCTs reported on the progression to new diabetes and found no effect of vitamin D (odds ratio 1.02; 95% CI 0.94 to 1.10, I(2) = 0%). Adverse events were rare, and there was no evidence of publication bias. CONCLUSIONS: Evidence from available trials shows no effect of vitamin D3 supplementation on glucose homeostasis or diabetes prevention. Definitive conclusions may be limited in the context of the moderate degree of heterogeneity, variable risk of bias, and short-term follow-up duration of the available evidence to date.
CONTEXT: Observational studies report consistent associations between low vitamin D concentration and increased glycemia and risk of type 2 diabetes, but results of randomized controlled trials (RCTs) are mixed. OBJECTIVE: The objective of the study was to systematically review RCTs that report on the effects of vitamin D supplementation on glucose homeostasis or diabetes prevention. DATA SOURCES: Sources of data for the study were MEDLINE, EMBASE, SCOPUS, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Technology Assessment, and Science Citation Index from inception to June 2013. STUDY SELECTION: Study selection was trials that compared vitamin D3 supplementation with placebo or a non-vitamin D supplement in adults with normal glucose tolerance, prediabetes, or type 2 diabetes. DATA EXTRACTION AND SYNTHESIS: Two reviewers collected data and assessed trial quality using the Cochrane Risk of Bias tool. Random-effects models were used to estimate mean differences (MDs) and odds ratios. The main outcomes of interest were homeostasis model assessment of insulin resistance, homeostasis model assessment of β-cell function, hemoglobin A1c levels, fasting blood glucose, incident diabetes, and adverse events. DATA SYNTHESIS: Thirty-five trials (43 407 patients) with variable risk of bias were included. Vitamin D had no significant effects on insulin resistance [homeostasis model assessment of insulin resistance: MD -0.04; 95% confidence interval (CI) -0.30 to 0.22, I-squared statistic (I(2)) = 45%], insulin secretion (homeostasis model of β-cell function: MD 1.64; 95% CI -25.94 to 29.22, I(2) = 40%), or hemoglobin A1c (MD -0.05%; 95% CI -0.12 to 0.03, I(2) = 55%) compared with controls. Four RCTs reported on the progression to new diabetes and found no effect of vitamin D (odds ratio 1.02; 95% CI 0.94 to 1.10, I(2) = 0%). Adverse events were rare, and there was no evidence of publication bias. CONCLUSIONS: Evidence from available trials shows no effect of vitamin D3 supplementation on glucose homeostasis or diabetes prevention. Definitive conclusions may be limited in the context of the moderate degree of heterogeneity, variable risk of bias, and short-term follow-up duration of the available evidence to date.
Authors: Ian H de Boer; Lesley F Tinker; Stephanie Connelly; J David Curb; Barbara V Howard; Bryan Kestenbaum; Joseph C Larson; JoAnn E Manson; Karen L Margolis; David S Siscovick; Noel S Weiss Journal: Diabetes Care Date: 2008-01-30 Impact factor: 19.112
Authors: Armin Zittermann; Sabine Frisch; Heiner K Berthold; Christian Götting; Joachim Kuhn; Knut Kleesiek; Peter Stehle; Heinrich Koertke; Reiner Koerfer Journal: Am J Clin Nutr Date: 2009-03-25 Impact factor: 7.045
Authors: Michael F Holick; Rachael M Biancuzzo; Tai C Chen; Ellen K Klein; Azzie Young; Douglass Bibuld; Richard Reitz; Wael Salameh; Allen Ameri; Andrew D Tannenbaum Journal: J Clin Endocrinol Metab Date: 2007-12-18 Impact factor: 5.958
Authors: Nicola Napoli; Anne L Schafer; Li-Yung Lui; Jane A Cauley; Elsa S Strotmeyer; Erin S Le Blanc; Andrew R Hoffman; Christine G Lee; Dennis M Black; Ann V Schwartz Journal: Bone Date: 2016-07-05 Impact factor: 4.398
Authors: Anastassios G Pittas; Bess Dawson-Hughes; Patricia Sheehan; James H Ware; William C Knowler; Vanita R Aroda; Irwin Brodsky; Lisa Ceglia; Chhavi Chadha; Ranee Chatterjee; Cyrus Desouza; Rowena Dolor; John Foreyt; Paul Fuss; Adline Ghazi; Daniel S Hsia; Karen C Johnson; Sangeeta R Kashyap; Sun Kim; Erin S LeBlanc; Michael R Lewis; Emilia Liao; Lisa M Neff; Jason Nelson; Patrick O'Neil; Jean Park; Anne Peters; Lawrence S Phillips; Richard Pratley; Philip Raskin; Neda Rasouli; David Robbins; Clifford Rosen; Ellen M Vickery; Myrlene Staten Journal: N Engl J Med Date: 2019-06-07 Impact factor: 91.245
Authors: Julia A Critchley; Blanca I Restrepo; Katharina Ronacher; Anil Kapur; Andrew A Bremer; Larry S Schlesinger; Randall Basaraba; Hardy Kornfeld; Reinout van Crevel Journal: Chest Date: 2017-04-20 Impact factor: 9.410
Authors: Naweed S Alzaman; Bess Dawson-Hughes; Jason Nelson; David D'Alessio; Anastassios G Pittas Journal: Am J Clin Nutr Date: 2016-05-18 Impact factor: 7.045
Authors: Deborah M Mitchell; Benjamin Z Leder; Enrico Cagliero; Natalia Mendoza; Maria P Henao; Douglas L Hayden; Joel S Finkelstein; Sherri-Ann M Burnett-Bowie Journal: Am J Clin Nutr Date: 2015-07-08 Impact factor: 7.045