vitamin d receptor (bsmi) genotypes influence inflammatory and oxidative stress responses to altered vitamin d intake in subjects with type 2 diabetes: a randomized controlled trial

b a ckground:  the purpose of our study was to investigate the possible effect of  bsm i vitamin d receptor (vdr’s) polymorphism on changes of the inflammatory and oxidative stress (os) biomarkers in response to daily intake of vitamin d- fortified yogurt drink ( doogh ) in subjects with type 2 diabetes (t2d). m ethods : in a randomized controlled trial, 100 t2d subjects were allocated to two groups to receive either plain  doogh  (pd; n = 50, containing 170 mg calcium and no vitamin d/250 ml) or vitamin d3-fortified  doog h  (fd; n = 50, containing 170 mg calcium and 500 iu/250 ml) twice a day for 12 weeks. 25(oh)d, glycemic status, inflammatory as well as os biomarkers were evaluated before and after the intervention. vdr- bsm i genotypes in an extended number of t2d subjects in the fd group (n = 140) were determined as bb, bb, and bb. results : after 12 weeks, in fd compared to pd, serum 25(oh)d increased (+30.0 nmol/l vs. −4.8 nmol/l, p < 0.001). the 25(oh)d, parathyroid hormone, highly sensitive c-reactive protein (hs-crp), malondialdehyde (mda), and glutathione (gsh) in patients with the bb genotype were more responsive to vitamin d intake in which the maximum increment in 25(oh)d was in bb (31.8 nmol/l) compared with  bb  (24.4  nmol/l)  and  bb  (20.8  nmol/l)  (p  for  trend  <  0.001),  and  the difference in bb, compared to bb and bb was significant [bb (p = 0.024) and bb (p = 0.037)]. this difference was accompanied by a significant difference for other biomarkers including fasting serum glucose (p trend = 0.039), fat mass % (p trend < 0.001), interleukin 6 (p trend = 0.033), hs-crp (p trend < 0.001), and mda (p trend = 0.028) which significantly all decreased in bb genotype except for gsh which significantly increased (p trend = 0.035). conclusion :  daily   intake   of   vitamin  d-fd   for   12   weeks   improved   the inflammatory and os biomarkers in t2d subjects, and the improvement was more pronounced in the carriers of bb genotype of vdr- bsm .