Association Between Vitamin D Levels and Vitamin D Receptor FokI Polymorphism in Thai Postmenopausal Women With Osteoporosis

Abstract

Background: Osteoporosis is a complex genetic disease, which is common among postmenopausal women. It is characterized by decreased bone mineral density (BMD) and increased bone fragility and fractures.
 Objective: To study the association between serum vitamin D levels and vitamin D receptor (VDR) genetic FokI polymorphism in postmenopausal women with osteoporosis.
 Methods: A total of 60 postmenopausal women who came for treatment at the menopausal clinic at Ramathibodi Hospital were enrolled. All of the patients had their BMD measured, and were determined serum vitamin D levels and VDR FokI polymorphism. Data were analyzed using chi-square and Fisher exact tests. The frequency of single nucleotide polymorphism (SNP) with risk of osteoporosis was compared.
 Results: Among 60 postmenopausal women, 26 (43.3%) women were an osteoporotic group and 34 (56.7%) women were non-osteoporotic group. There were no significant differences in age, vitamin D levels, or VDR FokI polymorphism between the groups (P > .05). However, the TT genotype of VDR FokI polymorphism was significantly associated with vitamin D deficiency (< 20 ng/mL) (OR, 6.15; 95% CI, 1.51 - 25.14; P < .05).
 Conclusions: Vitamin D levels and genotype of VDR FokI polymorphisms were similar between the osteoporotic and non-osteoporotic postmenopausal women. The TT genotype of VDR FokI polymorphism showed a significant association with vitamin D deficiency. Therefore, TT genotype of VDR FokI polymorphism may be used to predict risk of vitamin D deficiency.