Table 1 Inclusion and exclusion criteria

Inclusion

•Men aged 20 to 50 years

•Idiopathic asthenozoospermia (the mobility of sperm < 40% and rapid progressive sperm motility < 32%

•Serum vitamin D levels < 30 ng / ml

•Access to the infertility clinic of Ahvaz Jahad daneshgahi, Iran

•Inability to have a child after at least 1 y of marriage without using any preventive methods

•Normal fertile female partner

•No history (≤ 12 weeks) of medical therapy

•Not having a history of epididymo-orchitis, prostatitis, genital trauma, testicular torsion, inguinal or genital surgery, urinary tract infection, or previous hormonal therapy, another genital disease (cryptorchidism, current genital inflammation or varicocele), a recent history of sexually transmitted infection, hepatobiliary disease and renal insufficiency, severe general or central nervous system disease and endocrinopathy, using cytotoxic medications, immunosuppressant, anticonvulsants, androgens, antiandrogens

•No smoking, drug or alcohol abuse, and

•No occupational and environmental exposure to possible reproductive toxins

•Body mass index of < 30 kg/m²

Exclusion

• Have any acute illness

• Use less than 90% of the prescript supplement

• Would like to leave the study personally

• Participate in another study

• Immigrate

• Not available for following-up