Effects of vitamin D supplements on frequency of CD4+ T-cell subsets in women with Hashimoto's thyroiditis: a double-blind placebo-controlled study.

BACKGROUND: Vitamin D is a modulator of immune functions. Investigations on the mechanisms of vitamin D action and pathogenesis of Hashimoto's thyroiditis (HT) have revealed that vitamin D can reduce damages to thyroid cells caused by autoreactive immune cells. METHODS: Totally, 48 female patients with HT disease were introduced to the study by endocrinologists. Patients were divided into two major groups of 24 individuals and treated weekly with 50,000 IU of cholecalciferol (vitamin D group) or placebo (placebo group) using oral administration for 3 months. Eventually, 17 of the 24 patients in each group finished the study. Before and after supplementation, frequencies of Th1, Th17, Th2 and Tr1 cells and mean fluorescent intensity (MFI) of the associated cytokines, including IFN-γ, IL-17, IL-4 and IL-10, were assessed using flow cytometry. Furthermore, gene expression of IL-10 was assessed using real-time PCR. RESULTS: Results of this study showed that cholecalciferol supplementation caused a significant decrease in Th17/Tr1 ratio. The proportion and MFI of Th1, Th2, Tr1 and Th17 cells included no significant changes in vitamin D group, compared to those in placebo group. Expression rate and MFI of IL-10 increased in both groups. This increase was higher in vitamin D group than placebo group with no significance. CONCLUSIONS: In this novel preliminary clinical trial study, supplementation with cholecalciferol in HT patients for 3 months changed the balance of CD4+ T-cell subsets to improve the disease control. However, further studies are necessary to investigate effects of vitamin D on immune functions in HT patients.

Weight Changes and Metabolic Outcomes in Calorie-Restricted Obese Mice Fed High-Fat Diets Containing Corn or Flaxseed Oil: Physiological Role of Sugar Replacement with Polyphenol-Rich Grape.

OBJECTIVE: Because diet components are important during dieting in obesity treatment, we examined possible beneficial effects of substituting corn oil and sugar with flaxseed oil and grape in calorie-restricted high-fat diets on weight changes as well as improvement in some metabolic markers and related gene expression. METHODS: Seventy-five C57BL/6J male mice were given free access to a high-fat (36% of energy from fat) diet containing corn oil plus sugar (CO + S). After 11 weeks, 15 mice were sacrificed and another 60 were divided among 4 high-fat diet groups with 30% calorie restriction (CR) for the next 12 weeks. The diets contained corn oil (CO) or flaxseed oil (FO) with sugar (S) or grape (G). RESULTS: Despite CR, a weight loss trend was observed only during the first 4 weeks in all groups. CR did not significantly increase SIRT1 gene expression. Higher liver weight was observed in mice consuming FO (p < 0.05). Proliferator-activated receptor gamma (PPARγ) expression decreased in FO + G-CR significantly and even with a reduction of adiposity and higher adiponectin levels, fasting blood sugar (FBS) was significantly higher than in CO + G-CR. Grape intake increased Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) expression and decreased insulin resistance in CO + G-CR. CONCLUSIONS: Sugar replacement with polyphenol-rich grape along with CR improved glucose homeostasis, and substituting corn oil with flaxseed oil in obese mice reduced fat mass, but even with no change in adiponectin levels it could not decrease insulin resistance. However, none of the food item combinations facilitated weight reduction in the long-term CR. Therefore, regardless of the total calorie intake, different diet components and fat contents may have unexpected effects on metabolic regulation.