Objectives: To determine the effect of vitamin D supplementation on ovarian markers, endometrial quality and biochemical and clinical pregnancy rate.
Design: Randomized, double-blind (blind to participants and experimenters), placebo-controlled, single center.
Method: Inclusion criteria: Women in the age of 18 to 38 years ; having Primary infertility ; having female infertility approved by gynecologist ; using of long-term down-regulation protocol and then ovulation induction ; not using of vitamin D supplementation before the study ; not having a medical history of systemic disorders such as Cushing's syndrome, hyper or hypothyroidism, hyperprolactimenia ; no liver ,kidney and heart diseases ; having BMI Less than or equal to 30 KG/M2 or More than or equal to 18.9 KG/M2 ; not having clinical signs of vitamin D deficiency such as osteomalacia, osteoarthritis, the joint and bone pain and rheumatoid arthritis ; not using of drugs such as Phenytoin, Phenobarbital, Carbamazepine, Isoniazid, Rifampin Theophylline which may affect on vitamin D metabolism ; the absence of congenital or acquired uterine defects ; not having endometriosis. Exclusion criteria: Using surrogate uterine ; using the Oocyte donation ; Unwillingness to continue cooperation ; not having fertile follicle after injection of gonadotropin hormone. The total sample size: 85 cases. 42 cases in the intervention group and 43 cases in the control group. Intervention: 50000 units of vitamin D as a gelatin capsule was given weekly for 6 weeks to the intervention group and one placebo as a gelatin capsule was given weekly for 6 weeks to the control group.
outcome: Improvement in the number of oocytes , the embryos quality , the endometrium quality, and the incidence of clinical and biochemical pregnancy rates.