Researchers at the University of Medical Sciences in Tehran recently conducted a randomized controlled trial comparing a fortified yogurt drink containing vitamin D (1,000 IU/day) and either 600 or 900 mg of calcium to a placebo yogurt drink containing 300 mg of calcium. They looked at the response of a variety of “good and bad” proteins in 90 patients with type-2 diabetes over 12 weeks.
Neyestani TR, Nikooyeh B, Alavi-Majd H, Shariatzadeh N, Kalayi A, Tayebinejad N, Heravifard S, Salekzamani S, Zahedirad M. 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. J Clin Endocrinol Metab. 2012 Mar 22, 2012
They measured C-reactive protein (CRP) before and after treatment. CRP is a protein that rises in response to inflammation and is elevated in wide range of acute and chronic inflammatory conditions like infections, rheumatic and other inflammatory diseases, diabetes, malignancy, and heart disease. In Neyestani’s study, CRP went from 5.7 to 1.6 in the vitamin D group.
They measured several cytokines, which are small protein molecules used extensively in intercellular communication. Several inflammatory cytokines are induced by oxidant stress, by the very fact that living humans are on fire, making them important in chronic inflammation. Some examples of inflammatory cytokines are IL-1, IL-6, and TNF, which went from 489 to 155 and 155 to 116 respectively, while TNF did not change in the vitamin D group, perhaps due to the low dose of vitamin D.
They measured adiponectin, a protein hormone that moderates a number of metabolic processes, including glucose regulation. It is inversely associated with body weight (the higher the adiponectin the less you weigh). Supplementation with differing forms of adiponectin improved insulin control, blood glucose and triglyceride levels in mice. In this study, adiponectin went from 92 to 150 in the vitamin D group.
They also measured fibrinogen, a protein converted by thrombin into fibrin during blood coagulation. High levels are associated with excessive blood clotting, cardiovascular disease and inflammation. Fibrinogen went from 311 to 271 in the vitamin D group.
All four changes were significant (.01 or better). The total amount of calcium with the vitamin D, either 600 or 900 mg, did not matter. In some cases the lower dose of calcium combined with the vitamin D was more effective, though it appeared vitamin D was the active component, with the possible exception of adiponectin where calcium also played a role.
This is not the last we will hear about vitamin D and inflammation. In fact, Dr. Xavier Guillot and colleagues from Paris University published a good review several years ago.
They concluded, “Vitamin D exerts immunomodulating effects that may hold promise in many diseases characterized by inflammation, including autoimmune diseases, infections, malignancies, and cardiovascular diseases.”[/private]