In this double-blind randomized clinical trial, 60 patients aged 18-60y referred to Baharlou hospital with a history of mild to moderate depression diagnosed by a psychiatrist will be presented to the researcher. After receipt of a signed informed consent form, eligible patients will participate. A general demographic questionnaire will be completed by an interviewer. Individuals are randomly divided into intervention and control groups. A 10-ml venous blood sample will be collected from each participant. The intervention group receives 50000 IU of vitamin D every 2 weeks as vitamin D supplements for 8 weeks, provided monthly. The control group receives placebo. The drug schedule of both groups (if any) will be unchanged according to the prescribing physician. After 8 weeks, blood sample will be collected from each participant. The studied indices (inflammatory (IL-1β, IL-6, hs-CRP), PTH, platelet serotonin, serum oxytocin, serum 25(OH) D, depression status, anthropometry indices) will be evaluated at beginning and end of interventional period. Data will be analyzed by statistical tests.
Groups (intervention group receives 50000 IU vitamin D and control group receives placebo) through a random allocation. After 8 weeks, blood sample will be collected from each participant. The studied indices (inflammatory (IL-1β, IL-6, hs-CRP), PTH, platelet serotonin, serum oxytocin, serum 25(OH) D, depression status and anthropometry indices) will be evaluated at beginning and end of interventional period.