Vitamin D Receptor Polymorphisms and Efficacy of Vitamin D-Fortified Yogurt Drink in Patients With Type 2 Diabetes

In a 12-week randomized controlled trial ( double-blind study), based on data on serum 25(OH)D changes from other studies (35), to achieve 1 standard deviation difference in circulating 25(OH)D with two-sided alpha of 0.05 and a beta of 0.2 after a 12-week intervention period, the sample size was calculated 40 individuals per treatment group. Considering 3 polymorphic variant groups and one control group which receives plain yogurt drink, 160 subjects are needed. Allowing for 10% attrition over 12 weeks of intervention, a total of 180 subjects are required. In treatment groups, all patients receive 500 ml per day of low-fat (1%) Yogurt Drink fortified with approximately 500IU of vitamin D3 . Control group receives 500 ml per day of plain (unfortified) Yogurt Drink. Metabolic, inflammatory and oxidative stress markers are evaluated at the beginning and in the end of the interventional period.

Inclusion criteria

• Type 2 diabetes
• Informed consent
• BMI between 25 to 35 kg/m2
• Age: 30-45 years old
• Willingness to maintain current body weight for the duration of the study
• Willingness to maintain baseline lifestyle activities and routines for the duration of the study
• Willingness to avoid the use of all over-the-counter or prescription vitamins, dietary supplements, and herbal products during the study

Exclusion criteria

• History of cardiovascular , Gastrointestinal , Renal disease and any other endocrinological disorders
• Subjects receiving vitamin D or omega-3 supplement
• Pregnancy , or lactation within the study period
• Treatment with insulin
• Treatment for weight reduction
• Treatment for reducing serum lipids