en Human Genetics Human Genetics Original Research Original Research <p> <strong> Background: </strong>Osteoporosis, or porous bone, is a disease characterized by low bone mass density (BMD) and structural deterioration of bone tissue, leading to bone fragility and increased risk of hip, spine, and wrist fractures. There are numerous risk factors for osteoporosis. While many of these factors are non-genetic in nature, there is a definite genetic component responsible for this condition. The main aim of this study was to evaluate the association between VDR (Vitamin D receptor gene) polymorphisms (Fok1) A>G (rs2228570) and bone mineral density in an Iranian defined population. </p><p> <strong> Methods </strong>: The study participants comprised of 1032 Iranians recruited from the city of Sanandaj during IMOS (Iranian Multi Center Osteoporosis Study). Bone mineral density measurement was performed in all the participants with and without osteoporosis. All samples were genotyped for VDR genes (Fok1) polymorphism with polymerase chain reaction, using a predesigned TaqMan allele discrimination assay. </p><p> <strong> Results </strong>: There was a significant association between Fok1 polymorphism and osteoporosis in post-menopausal women, 0.138(0.025-0.768). </p><p> <strong> Conclusion </strong>: It seems that cohort studies, which are more powerful than case-control studies, can be useful in evaluating the roles of genetic variants as risk or protective factors for osteoporosis. </p> Osteoporosis, Vitamin D Receptor Gene, Fok1, Bone Mineral Density. 615 621 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-858&slc_lang=en&sid=1 Zahra Mohammadi Mimina_13@yahoo.com 200319475328460017392 200319475328460017392 No Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. Abbasali Keshtkar abkeshtkar@gmail.com 200319475328460017393 200319475328460017393 No Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. Fateme Fayyazbakhsh F.fba.te@gmail.com 200319475328460017394 200319475328460017394 No Biomedical Engineering Department, Maziar University, Rouyan, Iran. Mehdi Ebrahimi M_ebrahimi49@yahoo.com 200319475328460017395 200319475328460017395 No Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. Mahsa M Amoli mahsaamoli@hotmail.com 200319475328460017396 200319475328460017396 Yes Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. Mostafa Ghorbani mqorbani1379@yahoo.com 200319475328460017397 200319475328460017397 No Alborz University of Medical Sciences, Karaj, Iran. Patricia Khashayar Patricia.kh@gmail.com 200319475328460017398 200319475328460017398 No Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran. Mahboubeh Dini drmahdin@yahoo.com 200319475328460017399 200319475328460017399 No Non-communicable Disease Department, Iran Ministry of Health and Medical Education, Tehran, Iran Mina Ebrahimi-Rad minebrad@yahoo.com 200319475328460017400 200319475328460017400 No Biochemistry Department, Pasteur Institute of Iran, Tehran, Iran. Bagher Larijani 200319475328460017401 200319475328460017401 No Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.