The interactive effect of improvement of vitamin D status and VDR FokI variants on oxidative stress in type 2 diabetic subjects: a randomized controlled trial

• Published in: European journal of clinical nutrition Vol. 69; no. 2; pp. 216 - 222
• Main Authors: Shab-Bidar, S, Neyestani, T R, Djazayery, A
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.02.2015; Nature Publishing Group
• Subjects: 13/21; 25-Hydroxyvitamin D; 38/77; 692/308; 692/308/2056; Adult; Alfacalcidol; Antioxidants; Antioxidants - metabolism; Biomarkers; Biomarkers - blood; Bovine serum albumin; Calcifediol; Calciferol; Calcium; Calcium, Dietary - administration & dosage; Cholecalciferol - pharmacology; Clinical Nutrition; Deoxyribonucleases, Type II Site-Specific - genetics; Diabetes; Diabetes mellitus; Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - genetics; Diabetes Mellitus, Type 2 - metabolism; Epidemiology; Female; Food, Fortified; Genotype; Genotype & phenotype; Genotypes; Glutathione; Glutathione - blood; Health aspects; Humans; Internal Medicine; Male; Malondialdehyde; Malondialdehyde - blood; Medicine; Medicine & Public Health; Metabolic Diseases; Middle Aged; original-article; Oxidative stress; Oxidative Stress - drug effects; Physiological aspects; Polymorphism, Genetic; Public Health; Receptors, Calcitriol - genetics; Serum albumin; Subgroups; Superoxide dismutase; Superoxide Dismutase - blood; Type 2 diabetes; Vitamin D; Vitamin D - analogs & derivatives; Vitamin D - blood; Vitamin D receptors; Vitamin D3; Vitamins - pharmacology; Yogurt
• ISSN: 0954-3007; 1476-5640; 1476-5640
• DOI: 10.1038/ejcn.2014.240

Background/Objectives: The objectives were to evaluate the effects of improvement of vitamin D status on biomarkers of oxidative stress (OS) in type 2 diabetic (T2D) subjects and whether vitamin D receptor (VDR)- Fok I polymorphisms could modulate the response to vitamin D3 intake. Subjects/Methods: Subjects with T2D were allocated to one of the two groups to receive either plain doogh (PD; containing 150 mg calcium and no vitamin D/250 ml, n 1 =50) or vitamin D3-fortified doogh (FD; containing 500 IU/250 ml, n 1 =50) twice a day for 12 weeks. Outcomes were changes in serum 25-hydroxyvitamin D (25(OH)D), superoxide dismutase, glutathione (GSH), total antioxidant capacity (TAC) and malondialdehyde (MDA). VDR genotypes in 140 T2D subjects in FD were determined by Fok I restriction enzyme. Results: After 12 weeks, serum 25(OH)D increased significantly in FD (from 38.5±202.2 to 72.0±23.5, P <0.001) as compared with PD (from 38.8±22.8 to 33.4±22.8, P =0.28). Comparisons between FD and PD revealed significant differences in changes of serum MDA (−0.54±0.82 μmol/l vs +0.17±1 μmol/l, P <0.001), GSH (+8.4±40.1 ng/l vs −13.1±29.4 ng/l, P =0.002) and TAC (+0.14±0.43 mmol/l vs +0.02±0.45 mmol/l bovine serum albumin equivalent, P =0.03). Although there was no significant association between Fok I genotypes and OS biomarkers, ff variant subgroup showed the weakest response to vitamin D. Conclusions: Improvement of vitamin D status via daily intake of FD ameliorates OS biomarkers in T2D subjects and the interactive effect of Fok I genotypes cannot be ruled out.