Improvement of vitamin D status via daily intake of fortified yogurt drink either with or without extra calcium ameliorates systemic inflammatory biomarkers, including adipokines, in the subjects with type 2 diabetes

Abstract

Context: Systemic inflammation is thought to have a central role in diabetic long-term complications.

Objective: The aim of this study was to investigate the effects of vitamin D either with or without extra calcium on certain inflammatory biomarkers in the subjects with type 2 diabetes (T2D).

Design, setting, and participants: This was a double-blind, randomized, controlled trial conducted over 12 wk in 90 T2D subjects aged 30-60 yr from both sexes.

Intervention: Subjects were randomly allocated to one of three groups to receive two 250-ml bottles a day of plain Persian yogurt drink or doogh (PD, containing 150 mg calcium and no detectable vitamin D(3)/250 ml), vitamin D-fortified doogh (DD, containing 500 IU vitamin D(3) and 150 mg calcium/250 ml), or calcium + vitamin D(3)-fortified doogh (CDD, containing 500 IU vitamin D(3) and 250 mg calcium/250 ml).

Outcome measures: The changes in inflammatory markers were evaluated.

Results: Compared to the baseline values, highly sensitive C-reactive protein, IL-1β, IL-6, fibrinogen, and retinol binding protein-4 concentrations significantly decreased in both the DD and CDD groups. Although the decrement in highly sensitive C-reactive protein and fibrinogen was more in CDD compared to DD (-4.0 ± 8.5 vs. -1.3 ± 2.8 mg/liter, and -0.40 ± 0.74 and -0.20 ± 0.52 mg/liter, respectively), the differences were not significant. There was a significant increase in serum adiponectin in both the DD and CDD groups (51.3 ± 65.3 vs. 57.1 ± 33.8 μg/liter; P < 0.05). Mean adiponectin changes in CDD were significantly higher than in PD (P = 0.021).

Conclusions: Daily intake of vitamin D-fortified doogh improved inflammatory markers in T2D subjects, and extra calcium conferred additional benefit only for the antiinflammatory adipokine, i.e. adiponectin.

Trial registration: ClinicalTrials.gov NCT01229891.