Yvonne H M Krul-Poel1, Marieke M Ter Wee2, Paul Lips2, Suat Simsek3. 1. Department of Internal MedicineMedical Centre Alkmaar, Alkmaar, The Netherlands. 2. Department of Epidemiology and BiostatisticsVU University Medical Centre, Amsterdam, The Netherlands. 3. Department of Internal MedicineMedical Centre Alkmaar, Alkmaar, The Netherlands s.simsek@nwz.nl.
Abstract
OBJECTIVE: Epidemiologic studies suggest that vitamin D status plays a role in glycaemic control in patients with type 2 diabetes. However, intervention studies yielded inconsistent results. The aim of this study is to systematically review the effect of vitamin D supplementation on glycaemic control in patients with type 2 diabetes. METHODS: Systematic review and meta-analysis. We searched Medline, Embase and the Cochrane Library for RCTs examining the effect of vitamin D supplementation on glycaemic control in patients with type 2 diabetes. A random-effects model meta-analysis was performed to obtain a summarized outcome of vitamin D supplementation on HbA1c, fasting glucose and homeostasis model assessment - insulin resistance (HOMA-IR). RESULTS: Twenty-three RCTs were included in this systematic review representing a total of 1797 patients with type 2 diabetes. Mean (± s.d.) change in serum 25-hydroxyvitamin D varied from 1.8 ± 10.2 nmol/L to 80.1 ± 54.0 nmol/L. Nineteen studies included HbA1c as outcome variable. Combining these studies no significant effect in change of HbA1c was seen after vitamin D intervention compared with placebo. A significant effect of vitamin D supplementation was seen on fasting glucose in a subgroup of studies (n = 4) with a mean baseline HbA1c ≥ 8% (64 mmol/mol) (standardized difference in means: 0.36; 95% CI: 0.12-0.61, P = 0.003). CONCLUSIONS: Current evidence of RCTs does not support short-term vitamin D supplementation in a heterogeneous population with type 2 diabetes. However, in patients with poorly controlled diabetes, a favourable effect of vitamin D is seen on fasting glucose.
OBJECTIVE: Epidemiologic studies suggest that vitamin D status plays a role in glycaemic control in patients with type 2 diabetes. However, intervention studies yielded inconsistent results. The aim of this study is to systematically review the effect of vitamin D supplementation on glycaemic control in patients with type 2 diabetes. METHODS: Systematic review and meta-analysis. We searched Medline, Embase and the Cochrane Library for RCTs examining the effect of vitamin D supplementation on glycaemic control in patients with type 2 diabetes. A random-effects model meta-analysis was performed to obtain a summarized outcome of vitamin D supplementation on HbA1c, fasting glucose and homeostasis model assessment - insulin resistance (HOMA-IR). RESULTS: Twenty-three RCTs were included in this systematic review representing a total of 1797 patients with type 2 diabetes. Mean (± s.d.) change in serum 25-hydroxyvitamin D varied from 1.8 ± 10.2 nmol/L to 80.1 ± 54.0 nmol/L. Nineteen studies included HbA1c as outcome variable. Combining these studies no significant effect in change of HbA1c was seen after vitamin D intervention compared with placebo. A significant effect of vitamin D supplementation was seen on fasting glucose in a subgroup of studies (n = 4) with a mean baseline HbA1c ≥ 8% (64 mmol/mol) (standardized difference in means: 0.36; 95% CI: 0.12-0.61, P = 0.003). CONCLUSIONS: Current evidence of RCTs does not support short-term vitamin D supplementation in a heterogeneous population with type 2 diabetes. However, in patients with poorly controlled diabetes, a favourable effect of vitamin D is seen on fasting glucose.
Authors: Roger Bouillon; Claudio Marcocci; Geert Carmeliet; Daniel Bikle; John H White; Bess Dawson-Hughes; Paul Lips; Craig F Munns; Marise Lazaretti-Castro; Andrea Giustina; John Bilezikian Journal: Endocr Rev Date: 2019-08-01 Impact factor: 19.871
Authors: Maria E Balbi; Fernanda S Tonin; Antonio M Mendes; Helena H Borba; Astrid Wiens; Fernando Fernandez-Llimos; Roberto Pontarolo Journal: Diabetol Metab Syndr Date: 2018-03-14 Impact factor: 3.320