Study of Association among Vitamin D, Testosterone and Semen Quality in Fertile and Iraqi Infertile Men MUSTAFA T. ALBALDAWY 1 AND ALAAULDEEN S. ALSALAMI 2 1 MSc. Student, Department Of Biology, Faculty of science, Kufa University 2 Assist professor Dr., Department Of Biology, Faculty of science, Kufa University Abstract Objective: The objective of the study was to determination the biochemical changes and it’s relationships in each of three infertile groups (Teratozoospermia, infertile normozoospermia compare with fertile normozoospermia). Methods: Samples were collected at the Fertility Center Laboratories in Sadr Medical City, Najaf ,Iraq. Seminal fluid analysis were carried out on the samples, and samples that taken were 37 of Teratozoospermia, 34 of unexplained infertility samples and 17 of control group samples. A serum was then taken for biochemical tests, where vitamin D, vitamin D receptor (VDR), Testosterone, parathyroid hormone (PTH),Protamin enzyame 1( PRM1) by ELISA method and Calcium, Zinc by spectrophotometer test was measured. Results: The result showed a significant decrease (p<0.05) of VD, Ca+2 and Zn+2 levels in both Teratozoospermia and infertile normospermia compared with control group, While significant increased (p<0.05) of PTH and PRM1 levels in both Teratozoospermia and infertile normospermia compared with control group. And the results showed non-significant (p<0.05) in both VDR and testosterone hormone. Conclusion: A significant decrease and increase in the levels of each of above biochemical markers may be causes problem in infertile patients . Keywords: Infertility, VD, PTH, PRM1, Ca +2 , Zn +2 INTRODUCTION Infertility is a typical illness of the reproductive system, incapacity to have healthy birth following one year of effectively endeavors of unprotected free intercourses [1]. Around 15% of the couples on the planet confront failure in the primary involvement in pregnancy. These issues in these couples can be explained as infertility [2]. Male fertility depended on coordinated between hormonal and neural mechanism or amongst male reproductive system and these mechanisms. So any hindering, for at least one of these mechanisms will lead to infertility [3]. The imbalance of hormones have a critical significant among the reasons of infertility; hence, the examination of this flaw is essential in numerous pathologic cases that mirror the functional status of the endocrine glands [2], and because infertility in the world is a typical medical and social issue since the fifties of the most recent century and is around 15% of couples are suffer from infertility and around 40% of these percent are infertile by male factors which causes male infertility [4]. Semen examination is the most well- known essential test, considered unaltered, inexpensive, quick and rout test, that used as bedrock to determine the male infertility, but other reasons of infertility can't discovered by this test. So in view of different examinations that adopted as more precise screening test however not replaced to test of the seminal plasma [5]. In some cases, the sperms that have typical shape and normal count, despite this sperms can't fertilize the ova, because of biochemical disorder, this implies the typical values of seminal plasma test don't give ensure fertilization. Also, some defects in semen characteristics can know well the reasons for infertility for prevention from difficulties and treatment it all the more precisely [6]. On the other hand, most researchers show the significance of hormonal examination, other than screening of semen, the role functions of hormones by means of complex activities that is fundamental for spermatogenesis [7]. The factors of Male infertility are various, for example, varicocele that found in around 2-22% of infertile men that result from lessening level of Testosterone in serum [8]. In addition to hormonal defects, hereditary factors, environmental factors, coital factors and idiopathic factors that constitute around 25% of male infertility [9]. Some researchers classified reasons for infertility into four categories: male factors, female factors, congregated factors and idiopathic factors [10]. Additional factors that influence on male fertility involve weight of the body (body mass index), smoking and work [11]. Large quantities of biomarker proteins, a large number of essential protein and specific proteins in tissue that have been found in the seminal plasma that represent precise indicator for pathologic status related with reproductive system [12]. Vitamin D plays an important role in metabolism of calcium and phosphorus ions. Its primary activities involve absorption of intestinal calcium and reabsorption of renal calcium, and additionally an immediate impact on chondrocyte and osteoblast differentiation and resulting in bone formation [13]. The Accumulating evidence from human studies proposes that vitamin D, is side from its regulatory effects on musculoskeletal health, and is included in reproductive role in both sexes. The basis of the exchange between vitamin D and reproduction lays on the existence of both vitamin D receptors (VDR) and 1a-hydroxylase (CYP27B1) enzyme in the reproductive organs [14]. The Epidemiological studies supports a positive relationship among the concentration of serum 25-hydroxy-vitamin D [25(OH) D] and motility of the sperm in both fertile and infertile male [15]. Protamines (PRMs) includes the biggest amount of nucleoproteins in develop sperm of human. These proteins are translated in steps 1-4 of spermatids. While synthesis of the relating proteins begins, with temporal delay, in step 4 MUSTAFA T. ALBALDAWY et al /J. Pharm. Sci. & Res. Vol. 9(7), 2017, 1067-1071 1067