title: Vitamin D deficiency and low ionized calcium are linked with semen quality and sex steroid levels in infertile men.
abstract: Are low vitamin D levels linked with semen quality and sex steroids in infertile men?
  
  
  
  Infertile men with vitamin D deficiency had lower sperm motility, total numbers of motile sperm, Inhibin B, sex-hormone-binding-globulin (SHBG) and testosterone/estradiol ratio, but higher levels of free sex steroids, than infertile men with normal vitamin D levels.
  
  
  
  Low vitamin D levels have been associated with decreased sperm motility in healthy men, but a relationship between vitamin D and calcium with semen quality and especially sex steroids has not been sufficiently described in infertile men.
  
  
  
  This study comprises baseline characteristics of 1427 infertile men screened from 2011 to 2014 for inclusion in a randomized clinical trial, the Copenhagen-Bone-Gonadal Study.
  
  
  
  In total 1427 infertile men, consecutively referred to our tertiary andrological centre for fertility workup, underwent a physical examination and had semen quality assessed based on two samples and blood analysed for serum testosterone, SHBG, estradiol, inhibin B, luteinizing hormone, follicle-stimulating hormone (FSH), 25-hydroxyvitamin D (25-OHD), ionized calcium (Ca(2+)) and karyotype. There were 179 men excluded due to serious comorbidities or anabolic steroid usage, leaving 1248 patients for analyses.
  
  
  
  Men with 25-OHD >75 nmol/l had higher sperm motility and 66 and 111% higher total numbers of motile spermatozoa after 45 and 262 min, respectively, than men with 25-OHD <25 nmol/l (all P < 0.05). SHBG levels and testosterone/estradiol ratios were 15 and 14% lower, respectively, while free testosterone and estradiol ratios were 6 and 13% higher, respectively, in men with 25-OHD <25 nmol/l (all P < 0.05). Men with lower Ca(2+) levels had higher progressive sperm motility and inhibin B/FSH ratio but lower testosterone/estradiol ratio (all P < 0.05).
  
  
  
  All outcomes presented are predefined end-points but inferral of causality is compromised by the descriptive study design. It remains to be shown whether the links between vitamin D, calcium, semen quality and sex steroids in infertile men are causal.
  
  
  
  The associations between vitamin D deficiency and low calcium with semen quality and sex steroids support the existence of a cross-link between regulators of calcium homeostasis and gonadal function in infertile men.
  
  
  
  This study was supported by the Danish Agency for Science, Technology and Innovation, Hørslev Fonden, Danish Cancer Society and Novo Nordisk Foundation. There are no conflicts of interest.
  
  
  
  NCT01304927.
  
  
  
  25 February 2011.
  
  
  
  8 March 2011.
authors: Department of Growth and Reproduction and International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 9, Copenhagen DK-2100, Denmark Division of Bone and Mineral Research, Harvard School of Dental Medicine, Boston, MA, USA blombergjensen@gmail.com.
authors: Martin
authors: M
authors: Blomberg Jensen
authors: Department of Growth and Reproduction and International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 9, Copenhagen DK-2100, Denmark.
authors: Jacob
authors: J
authors: Gerner Lawaetz
authors: Department of Growth and Reproduction and International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 9, Copenhagen DK-2100, Denmark.
authors: Anna-Maria
authors: AM
authors: Andersson
authors: Department of Growth and Reproduction and International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 9, Copenhagen DK-2100, Denmark.
authors: Jørgen Holm
authors: JH
authors: Petersen
authors: Department of Growth and Reproduction and International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 9, Copenhagen DK-2100, Denmark.
authors: Loa
authors: L
authors: Nordkap
authors: Department of Growth and Reproduction and International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 9, Copenhagen DK-2100, Denmark.
authors: Anne Kirstine
authors: AK
authors: Bang
authors: Department of Growth and Reproduction and International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 9, Copenhagen DK-2100, Denmark.
authors: Pia
authors: P
authors: Ekbom
authors: Department of Growth and Reproduction and International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 9, Copenhagen DK-2100, Denmark.
authors: Ulla Nordström
authors: UN
authors: Joensen
authors: Department of Obstetrics and Gynaecology, Hvidovre Hospital, Copenhagen, Denmark.
authors: Lisbeth
authors: L
authors: Prætorius
authors: Fertility Clinic IVF, Ballerup, Denmark.
authors: Peter
authors: P
authors: Lundstrøm
authors: Danish Fertility Clinic, Frederiksberg, Denmark.
authors: Vibeke Hartvig
authors: VH
authors: Boujida
authors: Division of Bone and Mineral Research, Harvard School of Dental Medicine, Boston, MA, USA.
authors: Beate
authors: B
authors: Lanske
authors: Department of Growth and Reproduction and International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 9, Copenhagen DK-2100, Denmark.
authors: Anders
authors: A
authors: Juul
authors: Department of Growth and Reproduction and International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 9, Copenhagen DK-2100, Denmark.
authors: Niels
authors: N
authors: Jørgensen
mesh_terms: D000328:Adult; D002118:Calcium / Q000097:blood*; D004958:Estradiol / Q000097:blood*; D006801:Humans; D007248:Infertility, Male / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D007265:Inhibins / Q000097:blood; D008297:Male; D055101:Semen Analysis; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013081:Sperm Motility / Q000502:physiology*; D013739:Testosterone / Q000097:blood*; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood* / Q000150:complications / Q000503:physiopathology
chemical_list: D012738:Sex Hormone-Binding Globulin; C422364:inhibin B; D014807:Vitamin D; D013739:Testosterone; D004958:Estradiol; D007265:Inhibins; D002118:Calcium
keywords: calcium; fertility; reproduction; sex hormones; vitamin D