The aim of this study is to determine the effects of vitamin D or placebo for 3 months on the gene expression of glyoxalase enzyme, RAGE, and YKL40 in the peripheral blood mononuclear cell (PBMC) and serum levels of YKL40,AGEs, TNF-α, PAI-1, IL-6, and HbA1c of diabetes type 2 patients.

The aim of this study is to determine the effects of vitamin D or placebo for 3 months on the gene expression of plasma human cartilage glycoprotein 39(YKL40), receptor for advanced glycation end products (RAGE) and glyoxalase enzyme in the peripheral blood mononuclear cell (PBMC) and serum levels of YKL40 ,plasminogen activator inhibitor-1 (PAI-1), TNF-α, advanced glycation end products (AGEs ), IL-6, and HbA1c of diabetes type 2 patients.

In this randomized, double-blind clinical trial, placebo-controlled study, 84 women and men with type 2 diabetes are enrolled from the Iranian Center of diabetes. At the start of study, all participants will sign informed consent and complete a general information form. 24-hour food record for 3 days will be taken from the patients at the beginning and the end of the study. Selected samples by using stratified randomization method based on sex, gender and body mass index (BMI) are classified into 2 groups: 1) receiving vitamin D supplement 2) receiving vitamin D placebo bo.

The vitamin D supplement group will receive 4000 IU (100 microgram) daily for 3 months. The vitamin D placebo group will also receive placebo containing starch both similar in terms of color, shape and size. participants are advised to maintain their diet, level of physical activity and medication dose during the study. Blood samples will be collected after anthropometric parameter measuring then target biochemical parameters, gene expression and serum levels and physical activity will be measured before and after the trial.

Inclusion Criteria:

- diabetic type 2 patients 35-65 years old, body mass index in the range 18.5- 30 ,literate, willingness to participation,avoidance of dietary supplements, vitamins and herbal products at least 3 months before and throughout the intervention -

Exclusion Criteria:

• people who have used vitamin D supplements in last 3 months, having chronic renal disease , GI disease, Hepatobilliary diseases, hematological disorders, hypo- or hyperthyroidism, treatment with orlistat or sibutramine for weight loss, pregnancy and lactation, treatment with insulin or Thiazolidinediones, Smokers,sever change in regular diet and life style,change in type and dosage of regular medication (s)