ABSTRACT: Intervention 1: Intervention 1: a 50000 IU vitamin D tablet (Zahravi, Iran), weekly+ 2 omega-3 fatty acid capsules (each capsule containing 330 mg omega-3 fatty acid) (Minami Nutrition, Belgium), daily, for 8 weeks. Intervention 2: Intervention group 2: a 50000 IU vitamin D tablet (Zahravi, Iran), weekly+ 2 omega-3 fatty acid placebo (Zahravi, Iran), daily, for 8 weeks. Intervention 3: Intervention group 3: two omega-3 fatty acid capsules (each capsule containing 330 mg omega-3 fatty acid) (Minami Nutrition, Belgium), daily+ a vitamin D placebo (Zahravi, Iran), weekly, for 8 weeks. Intervention 4: Control group: a vitamin D placebo (Zahravi, Iran), weekly+ 2 omega-3 fatty acid placebo (Zahravi, Iran), daily, for 8 weeks.
Primary outcome(s): Serum level of TNF-a. Timepoint: Before and 8 weeks after intervention. Method of measurement: Serum TNF-a levels will be assessed by ELISA and Bender Med kit (Bender Med, Germany).
Study Design: Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Factorial, Purpose: Treatment, Randomization description: For randomized allocation performing, permuted block randomization will be used by quadrilateral blocks. According to the sample size of 80 subjects, 20 blocks will be generated using the online site (www.sealedenvelope.com). In order to allocation concealment in the randomized process, unique codes will be used on the drug boxes that is generated by the software. Participants will enter based on the sequence produced into study and the drug packets with code registered will allocate to the individual. Therefore, before participants selection, they will be unaware of the type of intervention that will receive, as well as a random sequence produced during the study will be immune from prediction, Blinding description: For blinding, a person who is not involved in study protocol created the randomization list assigning participants to the vit