www.medfak.ni.ac.rs/amm 16 Original article UDC: 612.015.6:616.71-007.233:618.173 VITAMIN D STATUS IN WOMEN WITH POSTMENOPAUSAL OSTEOPOROSIS Saša Milenković, Aleksandar Dimić, Aleksandra Stanković, Ivana Aleksić and Dejan Petrović The perturbation status of vitamin D can be manifested as insufficiency, deficiency and excessiveness. Vitamin D status within the organism is determined by measuring the level of 25(OH)D in the serum. The aim of this paper was to determine the vitamin D status in postmenopausal women with newly diagnosed osteoporosis as well as to correlate vitamin D status with bone mineral density (BMD) and bones' fractures. The research included 58 postmenopausal women who have recently been given the diagnosis of postmenopausal osteoporosis. All the examinees were determined with the level of 25(OH)D as well as the levels of unspecific markers of the bone metabolism. All of the examinees were defined with their bone mineral density on the lumbar spine and hip, measured with DEXA densitometer. The average age of the examinees was 60,46±6,55 years, average duration of menopause 15,02±9,25 years and average concentration of 25(OH)D 46,45±14,68 nmol/L. Our results has shown the deficiency of vitamin D in 89,76% of the examinees with postmenopausal osteoporosis, positive correlation of the level of 25(OH)D and bone mineral density (BMD) and a significantly lower initial concentration of 25(OH)D with the examines with prior bone fractures opposed to those without fractures (37,57±13,08 vs. 51,22±17,26 nmol/L; p<0,02). The obtained results show that vitamine D deficiency in postmenopausal women with osteporosis present important risk factors for bones fractures as well as factors for decreasing the bone mineral density. Acta Medica Medianae 2010;49(4):16-18. Key words: Vitamin D, osteoporosis, postmenopausal women Clinic of Rheumatology, Institute for Treatment and Rehabilitation "Niška Banja"- Niška Banja Contact: Saša Milenković Clinic of Rheumatology, Institute for Treatment and Rehabilitation« Niška Banja« Srpskih junaka 2, Niška Banja E-mail: ela03@bankerinter.net Introduction Vitamin D, its active metabolites and analogues represent the group of compounds with numerous functions within the organism. The primary role of vitamin D is in the metabolism of phosphorus and calcium. It is well-known that vitamin D increases intestinal and tubular absorption of calcium. Nowadays, it is also known that vitamin D decreases the physiological activity of para- thormon (PTH) in the following ways: directly, by affecting parathyroid glands, and also indirectly by hypercalcemia (1). It is also known that vitamin D helps with bone formation. Affecting the osteoblasts via vitamin D receptors (VDR) increases the synthesis of osteoclacin, alkaline phosphatase (ALP) and the collagen type I. The effect of vitamin D on osteoclasts is double: indirect – via osteoblasts (RANKL/RANK/osteoprote- gerin system), and directly – by suppression of differentiation from promyelocytes to monocytes, that are the precursors of osteoclasts (2). By regulation of calcium metabolism in muscle cells, vitamin D affects the muscle tissue which is significant for the process of contraction and relaxation of muscle fibers (3). Besides endocrine function, vitamn D has numerous paracrine functions which it achieves by controlling over 200 genes, including genes responsible for the regulation of mineralization process, the differen- iation of cells, and regulation of apoptosis and angiogenesis process (4). The status perturbation of vitamin D can be manifested as insufficiency, deficiency and excessiveness. Risk factors for insufficiency of vitamin D are: nourishment disorder, life style (sun exposure less than 15 minutes per day, old age and occult malab- rption, kidney and liver function disorder as well as the mutation of VDR (rare risk factors). Vitamin D status within the organism is deter- ined by measuring the level of 25(OH)D in the serum (5).