Effects of calcium‚Äìvitamin D co-supplementation on glycaemic control, inflammation and oxidative stress in gestational diabetes: a randomised placebo-controlled trial
Authors: Ahmad Esmaillzadeh
Maryam Karamali
Zatollah Asemi
Journal: Diabetologia (2014)
Discipline: CLINICAL MEDICINE
Keywords: calcium; vitamin D; supplementation; pregnant women; gestational diabetes mellitus
Affiliations: Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, I. R., Iran.

Abstract:  Aims/hypothesis: This study was designed to assess the effects of calcium and vitamin D supplementation on the metabolic status of pregnant women with gestational diabetes mellitus (GDM). Methods: This randomised placebo-controlled trial was performed at maternity clinics affiliated to Kashan University of Medical Sciences, Kashan, Iran. Participants were 56 women with GDM at 24-28 weeks' gestation (18 to 40 years of age). Subjects were randomly assigned to receive calcium plus vitamin D supplements or placebo. All study participants were blinded to group assignment. Individuals in the calcium-vitamin D group (n = 28) received 1,000 mg calcium per day and a 50,000 U vitamin D3 pearl twice during the study (at study baseline and on day 21 of the intervention), and those in the placebo group (n = 28) received two placebos at the mentioned times. Fasting blood samples were taken at study baseline and after 6 weeks of intervention. Results: The study was completed by 51 participants (calcium-vitamin D n = 25, placebo n = 26). However, as the analysis was based on an intention-to-treat approach, all 56 women with GDM (28 in each group) were included in the final analysis. After the administration of calcium plus vitamin D supplements, we observed a significant reduction in fasting plasma glucose (-0.89 ¬± 0.69 vs +0.26 ¬± 0.92 mmol/l, p &lt; 0.001), serum insulin levels (-13.55 ¬± 35.25 vs +9.17 ¬± 38.50 pmol/l, p = 0.02) and HOMA-IR (-0.91 ¬± 1.18 vs +0.63 ¬± 2.01, p = 0.001) and a significant increase in QUICKI (+0.02 ¬± 0.03 vs -0.002 ¬± 0.02, p = 0.003) compared with placebo. In addition, a significant reduction in serum LDL-cholesterol (-0.23 ¬± 0.79 vs +0.26 ¬± 0.74 mmol/l, p = 0.02) and total cholesterol: HDL-cholesterol ratio (-0.49 ¬± 1.09 vs +0.18 ¬± 0.37, p = 0.003) and a significant elevation in HDL-cholesterol levels (+0.15 ¬± 0.25 vs -0.02 ¬± 0.24 mmol/l, p = 0.01) was seen after intervention in the calcium-vitamin D group compared with placebo. In addition, calcium plus vitamin D supplementation resulted in a significant increase in GSH (+51.14 ¬± 131.64 vs -47.27 ¬± 203.63 Œºmol/l, p = 0.03) and prevented a rise in MDA levels (+0.06 ¬± 0.66 vs +0.93 ¬± 2.00 Œºmol/l, p = 0.03) compared with placebo. Conclusions/interpretation: Calcium plus vitamin D supplementation in women with GDM had beneficial effects on their metabolic profile. Trial registration: www.irct.ir IRCT201311205623N11. Funding: The study was supported by a grant (no. 92110) from Kashan University of Medical Sciences. 

Retracted: No

PubPeer comments:
 There are many concerns about the integrity of 172 publications by this research group, including this one. Some of the concerns are published 1. Anaesthesia 2020;75:1683u201392, see Supplementary data. This paper is A12 2. Account Res 2020; 28:149-61. 3. J Clin Epidemiol 2021;131:22-29. Journals and publishers were notified of these concerns in July 2019. 23 publications have an expression of concern. To our knowledge there has been no public response about any of the concerns. We think these publications are unreliable ,