IRCT20180805040703N1 IRCT 2018-10-20 Institute for Endocrine Science Effects of different dosages of vitamin D3 on anthropometric indices, metabolic, bone, and vascular parameters and body composition Effects of different dosages of vitamin D3 on anthropometric indices, metabolic, bone, and vascular parameters and body composition in overweight or obese children and adolescents 2016-06-20 anticipated 327 Complete https://irct.ir/trial/33444 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Not used, Assignment: Parallel, Purpose: Prevention, Randomization description: Children and adolescents will be randomized using stratified block randomization method in each intervention group (2000 IU vitamin D, 1000 IU vitamin D, and 600 IU vitamin D), before which important confounders including sex (boy or girl), body mass index (overweight or obesity), and pubertal stage (pre-puberty and puberty) are determined. Eight strata including 3-blocks of A, B and C (3 intervention groups) are determined (ABC, BCA, CAB, ACB, BAC, CBA). Thus, at the end of the study, the three therapeutic groups in terms of confounding factors, including sex, body mass index, and pubertal stage will be the same and with an equal number of subjects, Blinding description: in this study participants were aware of dosage of vitamin D supplementation they received. but, the investigator was blind for randomization of participants. so there was no awareness of the dose received by each person. 3 Condition 1: over weight and obesity, cardiovascular disease. Condition 2: vitamin D deficiency. Intervention 1: Intervention group1: 12 months oral vitamin D supplementation of 2000 IU/d (ZAHRAVI pharmaceutical company-Tabriz-Iran). Intervention 2: Intervention group2: 12 months oral vitamin D supplementation of 1000 IU/d (ZAHRAVI pharmaceutical company-Tabriz-Iran). Intervention 3: Control group: 12 months oral vitamin D supplementation of 600 IU/d (ZAHRAVI pharmaceutical company-Tabriz-Iran). Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is there is no more information