Improvement of vitamin D status resulted in amelioration of biomarkers of systemic inflammation in the subjects with type 2 diabetes

Background Both vitamin D deficiency and inflammation have been linked to cardiovascular disease, the major cause of death in diabetes. In this study, the effects of daily intake of vitamin D‐fortified yoghourt drink ( doogh ) on systemic inflammatory biomarkers in subjects with type 2 diabetes (T2D) were investigated. Subjects and methods In this 12‐week randomized controlled trial, T2D subjects received either plain doogh (PD; containing 170 mg calcium and no detectable vitamin D/250 mL, n 1  = 50) or vitamin D3‐fortified doogh (FD; containing 170 mg calcium and 500 IU/250 mL, n 2  = 50) twice a day. Glycemic status, body fat mass and systemic inflammatory biomarkers including serum highly sensitive C‐reactive protein (hsCRP), serum amyloid A (SAA), interleukin(IL)‐2, IL‐6, IL‐10 and tumour necrosis factor (TNF)‐ α were evaluated at the beginning and after the intervention. Data were expressed as either mean ± SD or median (interquartile range) whenever they had either normal or non‐normal distribution, respectively. Results In the patients receiving the vitamin D fortified drink, compared with those receiving the unfortified drink, a significant increase in serum 25(OH)D was accompanied by significant changes in TNF‐ α (−57.9 (−264.6) versus +106.3 (683.2), p  = 0.044), IL‐6 (−6.3 (−69.2), p  = 0.002), hsCRP (−0.39 (−1.50) versus +0.8 (1.52), p  < 0.001), SAA (−14.2 ± 44.5 versus +5.6 ± 37.5 mg/L, p  = 0.022) and IL‐10 (+38.7 ± 157.0 versus −51.9 ± 165.2 ng/L, p  = 0.013). The between‐group differences of hsCRP, SAA and IL‐6 changes remained significant even after controlling for changes quantitative insulin check index ( p  < 0.001, p  < 0.001 and p  = 0.009, respectively). Conclusions Improvement of vitamin D status of T2D subjects resulted in amelioration of the systemic inflammatory markers. This may have preventive implications against cardiovascular disease and other diabetic complications. Copyright © 2012 John Wiley & Sons, Ltd.