Role of rs2762934 and rs4809957 polymorphisms of CYP24A1 on outcomes of vitamin D treatment in postmenopausal osteoporotic women in Iraq

Osteoporosis is widely distributed condition characterized by bone weakness making it more fragile and easier to be fractured. Various elements enter in bone structure making it rigid to tolerate body weight and any accident. Many factors had a role in progression of osteoporosis such as age, gender, medications, and genetic variations in enzymes responsible for vitamin D metabolism. The aim of the current study is to evaluate role of polymorphism of metabolic enzyme CYP24A1 on responding to vitamin D in postmenopausal osteoporotic women. Forty postmenopausal women were followed up for 2 months and took 50000IU/week of vitamin D during study period, and 30 postmenopausal women without osteoporosis as a control group. Blood samples were taken pre- and post-treatment to determine responder to vitamin D therapy. Regarding vitamin D level, there was a significant difference between responder and non-responder at pre-treatment levels. GG genotype of rs2762934 SNP and AA genotype of rs4809957 SNP are the predominant in non-responder group, and both genotypes showed negative correlation to being responsiveness to vitamin D therapy. The homozygote wild GG genotype of rs2762934 predict vitamin D non-responsiveness in sample of osteoporotic postmenopausal women. The AA genotype of the rs2762934 substantially increases the responsiveness while AA of rs4809957 is associated with non-responsiveness. In conclusion, this study will implicate in correct choosing the desired dose of vitamin D for desired osteoporotic women to get better response and avoid any harmful effect of vitamin D overdose.