Inclusion Criteria:  Female subject age >18 years. Clinical and/or biochemical hyperandrogenism and the proven PCOS by the "Rotterdam" criteria, (ovarian dysfunction, oligo- and/or anovulation, and the morphology of polycystic ovaries on ultrasound images when other etiologies are excluded) 25(OH)D levels are between 10-28 ng/ml by inclusion Subject can not be under any kind of ongoing hormone or metformin therapies and no indication that requires continuation Has the ability and willingness to understand and comply with study procedures and to give written informed consent prior to enrollment in the study or initiation of study procedures Study subject has the ability and willingness to understand and comply with study procedures and to give written informed consent prior to enrollment in the study or initiation of study procedures  Exclusion Criteria:  Has been exposed to any investigational agent within 3 month of enrolment to the study Sever metabolic disease on endocrine disease in etiology different from PCOS Significant obesity (BMI> 36) Any other signs of lab results that may lead to other etiologies in differentiation, or menopause Increased serum calcium level results or symptoms of hypercalcemia in last one year Hypercalciuria or kidney stone appearance in last one year Sever kidney diseases (CKD 3 or higher) Chronic or serious disease, which can significantly influence the absorption, metabolism of vitamin D or Ca Heart failure or angina pectoris, More than 1000 IU vitamin D per day intake or in total >5000 IU per week within 1 month prior to trial (in any forms medication, or nutritional food supplement). The patient is not under hormonal therapy for ovulation stimulation purposes and was not involved in two months prior the study The patient is under hormonal therapy for the aim of ovulation stimulation or was involved in within 3 months prior the study Existence or suspected gravidity Any other finding or symptoms which are by the opinion of the Investigator may indicate a potential interference with the safety of participating trial subjects Has a known hypersensitivity to any of the investigational drug or vehicle components.  Concomitant medication which is not allowed:  glycosides metformin magnesium-containing preparations (antacids) cholestyramine and other ion exchange resins, orlistat thiazide diuretics regular use of microsomal enzyme inducers (anticonvulsants, sedatives, etc.). corticosteroids (except for dermatological use) products containing phosphorus regular use of laxatives (such as paraffin oil) fat absorption inhibitory drugs any kind of hormone therapy (including therapeutic use of birth control pills, within 2 months prior inclusion) except treatment of stabile hypothyroidism