Effects of vitamin D supplementation on semen quality, reproductive hormones, and live birth rate: a randomized clinical trial
Open accessAbstract
Context: Results of animal models and cross-sectional cohort studies have suggested a beneficial role for vitamin D in male reproduction. Objective: Determine the effect of vitamin D and calcium supplementation on semen quality in infertile men with serum 25-hydroxyvitamin-D (25OHD) levels ≤50 nmol/L. Design: A single-center, triple-blinded, randomized clinical trial. Participants: A total of 1427 infertile men were screened to include 330; 1002 men did not meet inclusion criteria and 95 did not wish to participate. Intervention: The active group received cholecalciferol 300,000 IU initially, then 1400 IU cholecalciferol and 500 mg of calcium daily for 150 days; the other group received placebo. Results: Serum concentrations of 25OHD and 1,25-dihydroxyvitamin D3 were significantly higher in men in the treatment group compared with the placebo group. Vitamin D supplementation was not associated with changes in semen parameters, although spontaneous pregnancies tended to be higher in couples in which the man was in the treatment group [7.3% vs 2.4%, Δ5.0% (-0.6%; 10.5%)]. Vitamin D treatment in a subgroup of oligozoospermic men increased the chance for a live birth compared with placebo [35.6% vs 18.3%, Δ17.3% (1.6%; 32.9%)]. Moreover, serum inhibin B levels were higher in men deficient in vitamin D who were randomly assigned to receive high-dose vitamin D [193 pg/mL vs 143 pg/mL, Δ49 pg/mL (8; 91 pg/mL)]; however, the increase in sperm concentration was not significantly higher than in the placebo group (P = 0.07). Conclusion: High-dose vitamin D supplementation did not improve semen quality in vitamin D-insufficient infertile men. The positive impact of vitamin D supplementation on live birth rate and serum inhibin B in oligozoospermic and vitamin D-deficient men may be of clinical importance and warrant verification by others.
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Similar to the MOXI trial, the high quality trials included in the Cochrane review did not find a benefit to antioxidants on live birth.
“Similar to the MOXI trial, the high quality trials included in the Cochrane review did not find a benefit to antioxidants on live birth. (25, 26)”
From The effect of antioxidants on male factor infertility: the Males, Antioxidants, and Infertility (MOXI) randomized clinical trial (2020) · cites this paper as [25]
The Secondary end points and Discussion sections (pages unavailable) report no overall live-birth benefit from vitamin D plus calcium in this trial. Our copy does not address whether high-quality trials in a Cochrane review found no live-birth benefit from antioxidants; searches for the Cochrane review, antioxidants, and the MOXI trial found no supporting passage. (LLM, conf=0.76)
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Slama, R. (2002) · Human Reproduction · doi:10.1093/humrep/17.2.503 · Cited by 308 · see citing works
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Research works printed but not linked: 33
- Skakkebaek NE, Rajpert-De Meyts E, Buck Louis GM, Toppari J, Andersson AM, Eisenberg ML, Jensen TK, Jørgensen N, Swan SH, Sapra KJ, Ziebe S, Priskorn L, Juul A. Male reproductive disorders and fertility trends: influences of environment and genetic sus- ceptibility. Physiol Rev. 2016;96(1):55-97.
- Kupka MS, Ferraretti AP, de Mouzon J, Erb K, D'Hooghe T, Castilla JA, Calhaz-Jorge C, De Geyter C, Goossens V; European IVF-Monitoring Consortium, for the European Society of Human Reproduction and Embryology. Assisted reproductive technology in Europe, 2010: results generated from European registers by ESHRE. Hum Reprod. 2014;29(10):2099-2113.
- Jain T, Gupta RS. Trends in the use of intracytoplasmic sperm injection in the United States. N Engl J Med. 2007;357(3):251-257.
- Krausz C. Male infertility: pathogenesis and clinical diagnosis. Best Pract Res Clin Endocrinol Metab. 2011;25(2):271-285.
- Blomberg Jensen M. Vitamin D and male reproduction. Nat Rev Endocrinol. 2014;10(3):175-186.
- T üttelmann F, Laan M, Grigorova M, Punab M, S õber S, Gromoll J. Combined effects of the variants FSHB -211G.T and FSHR 2039A.G on male reproductive parameters. J Clin Endocrinol Metab. 2012;97(10):3639-3647.
- Bouillon R, Carmeliet G, Verlinden L, van Etten E, Verstuyf A, Luderer HF, Lieben L, Mathieu C, Demay M. Vitamin D and human health: lessons from vitamin D receptor null mice. Endocr Rev. 2008;29(6):726-776.
- van Schoor NM, Lips P. Worldwide vitamin D status. Best Pract Res Clin Endocrinol Metab. 2011;25(4):671-680.
- Lips P. Vitamin D physiology. Prog Biophys Mol Biol. 2006;92(1): 4-8.
- Thacher TD, Clarke BL. Vitamin D insufficiency. Mayo Clin Proc. 2011;86(1):50-60.
- Uhland AM, Kwiecinski GG, DeLuca HF. Normalization of serum calcium restores fertility in vitamin D-deficient male rats. J Nutr. 1992;122(6):1338-1344.
- Kwiecinski GG, Petrie GI, DeLuca HF. Vitamin D is necessary for reproductive functions of the male rat. J Nutr. 1989;119(5): 741-744.
- Sun W, Chen L, Zhang W, Wang R, Goltzman D, Miao D. Active vitamin D deficiency mediated by extracellular calcium and phosphorus results in male infertility in young mice. Am J Physiol Endocrinol Metab. 2015;308(1):E51-E62.
- Kinuta K, Tanaka H, Moriwake T, Aya K, Kato S, Seino Y. Vitamin D is an important factor in estrogen biosynthesis of both female and male gonads. Endocrinology. 2000;141(4):1317-1324.
- Blomberg Jensen M, Bjerrum PJ, Jessen TE, Nielsen JE, Joensen UN, Olesen IA, Petersen JH, Juul A, Dissing S, Jørgensen N. Vi- tamin D is positively associated with sperm motility and increases intracellular calcium in human spermatozoa. Hum Reprod. 2011; 26(6):1307-1317.
- Yang B, Sun H, Wan Y, Wang H, Qin W, Yang L, Zhao H, Yuan J, Yao B. Associations between testosterone, bone mineral density, vitamin D and semen quality in fertile and infertile Chinese men. Int J Androl. 2012;35(6):783-792.
- Zhu CL, Xu QF, Li SX, Wei YC, Zhu GC, Yang C, Shi YC. In- vestigation of serum vitamin D levels in Chinese infertile men. Andrologia. 2016;48(10):1261-1266.
- Blomberg Jensen M, Gerner Lawaetz J, Andersson AM, Petersen JH, Nordkap L, Bang AK, Ekbom P, Joensen UN, Prætorius L, Lundstrøm P, Boujida VH, Lanske B, Juul A, Jørgensen N. Vitamin D deficiency and low ionized calcium are linked with semen quality and sex steroid levels in infertile men. Hum Reprod. 2016;31(8): 1875-1885.
- Jørgensen N, Liu F, Andersson AM, Vierula M, Irvine DS, Auger J, Brazil CK, Drobnis EZ, Jensen TK, Jouannet P, Overstreet JW, Redmon JB, Sparks A, Toppari J, Wang C, Skakkebæk NE, Swan SH. Serum inhibin-b in fertile men is strongly correlated with low but not high sperm counts: a coordinated study of 1,797 European and US men. Fertil Steril. 2010;94(6):2128-2134.
- Treasure T, MacRae KD. Minimisation: the platinum standard for trials? Randomisation doesn't guarantee similarity of groups; minimisation does. BMJ. 1998;317(7155):362-363.
- Dawson-Hughes B, Heaney RP, Holick MF, Lips P, Meunier PJ, Vieth R. Estimates of optimal vitamin D status. Osteoporos Int. 2005;16(7):713-716.
- Vieth R. Vitamin D supplementation, 25-hydroxyvitamin D con- centrations, and safety. Am J Clin Nutr. 1999;69(5):842-856.
- Jørgensen N, Joensen UN, Jensen TK, Jensen MB, Almstrup K, Olesen IA, Juul A, Andersson AM, Carlsen E, Petersen JH, Toppari J, Skakkebæk NE. Human semen quality in the new millennium: a prospective cross-sectional population-based study of 4867 men. BMJ Open. 2012;2(4):e000990.
- Evenson D, Jost L. Sperm chromatin structure assay is useful for fertility assessment. Methods Cell Sci. 2000;22(2-3):169-189.
- Rosen CJ, Gallagher JC. The 2011 IOM report on vitamin D and calcium requirements for North America: clinical implications for providers treating patients with low bone mineral density. J Clin Densitom. 2011;14(2):79-84.
- Guzick DS, Overstreet JW, Factor-Litvak P, Brazil CK, Nakajima ST, Coutifaris C, Carson SA, Cisneros P, Steinkampf MP, Hill JA, Xu D, Vogel DL; National Cooperative Reproductive Medicine Network. Sperm morphology, motility, and concentration in fertile and infertile men. N Engl J Med. 2001;345(19):1388-1393.
- Zinaman MJ, Brown CC, Selevan SG, Clegg ED. Semen quality and human fertility: a prospective study with healthy couples. J Androl. 2000;21(1):145-153.
- Carlsen E, Swan SH, Petersen JH, Skakkebaek NE. Longitudinal changes in semen parameters in young Danish men from the Copenhagen area. Hum Reprod. 2005;20(4):942-949.
- Andersen AG, Ziebe S, Jørgensen N, Petersen JH, Skakkebaek NE, Andersen AN. Time to pregnancy in relation to semen quality assessed by CASA before and after sperm separation. Hum Reprod. 2002;17(1):173-177.
- Boisen IM, Bøllehuus Hansen L, Mortensen LJ, Lanske B, Juul A, Blomberg Jensen M. Possible influence of vitamin D on male re- production. J Steroid Biochem Mol Biol. 2017;173:215-222.
- Bøllehuus Hansen L, Rehfeld A, de Neergaard R, Nielsen JE, Iversen LH, Boisen IM, Mortensen LJ, Lanske B, Almstrup K, Carlsen E, Berg AH, Jørgensen N, Andersen AN, Juul A, Blomberg Jensen M. Selection of high quality spermatozoa may be promoted by activated vitamin D in the woman. J Clin Endocrinol Metab. 2017;102(3):950-961.
- Blomberg Jensen M, Jørgensen A, Nielsen JE, Bjerrum PJ, Skalkam M, Petersen JH, Egeberg DL, Bangsbøll S, Andersen AN, Skakkebaek NE, Juul A, Rajpert-De Meyts E, Dissing S, Leffers H, Jørgensen N. Expression of the vitamin D metabolizing enzyme CYP24A1 at the annulus of human spermatozoa may serve as a novel marker of semen quality. Int J Androl. 2012;35(4):499-510.
- Blomberg Jensen M. Vitamin D metabolism, sex hormones, and male reproductive function. Reproduction. 2012;144(2): 135-152.
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“Lower calcium intake levels were associated with higher sperm motility and a more favourable hormone profile (21).”
BackgroundVitamin D and Obesity: Two Interacting Players in the Field of Infertility
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“Supplementation of vitamin D improved semen quality and pregnancy rates [32,33].”
BackgroundVitamin D and reproductive disorders: a comprehensive review with a focus on endometriosis
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BackgroundMo, M., Wang, S.-J., Chen, Z., Muyiduli, X., Wang, S.-J., Shen, Y., Shao, B., Li, M., Chen, D.-Q., Chen, Z.-X., et al. (2019) · European Journal of Clinical Nutrition · doi:10.1038/s41430-019-0417-x · Cited by 41 · see citing works
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Self-citationMaghsoumi‐Norouzabad, L., Javid, A. Z., Mansoori, A., Dadfar, M., & Serajian, A. (2021) · Nutrition Journal · doi:10.1186/s12937-021-00711-7 · Cited by 21 · see citing works
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Self-citationRimmer, M., Howie, R., Subramanian, V., Anderson, R., Bertolla, R., Beebeejaun, Y., Bortoletto, P., Sunkara, S., Mitchell, R., Pacey, A., et al. (2022) · Human Reproduction Open · doi:10.1093/hropen/hoac010 · Cited by 16 · see citing works
“…et al., 2017; Qu et al., 2017; Rosety et al., 2017; Taiyeb et al., 2017; Hajizadeh Maleki and Tartibian, 2017a,b; Babak et al., 2018; Blomberg Jensen et al., 2018; Bodin et al., 2018; Busetto et al., 2018; Habous et al., 2018; Hajizadeh Maleki and Tartibian, 2018; Ketabchi and Salajegheh,…”
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MethodMortensen, L. J., Lorenzen, M., Jørgensen, N., Andersson, A., Nielsen, J. E., Petersen, L. I., Lanske, B., Juul, A., Hansen, J. B., & Jensen, M. B. (2019) · Bone · doi:10.1016/j.bone.2019.03.022 · Cited by 20 · see citing works
Self-citationWall-Gremstrup, G., Holt, R., Yahyavi, S. K., Jorsal, M. J., Juul, A., Jørgensen, N., & Jensen, M. B. (2024) · Respiratory Research · doi:10.1186/s12931-023-02642-9 · Cited by 19 · see citing works
“Flow and safety outcome of the primary data concerning semen quality and changes in glucose and lipid homeostasis have been published [30, 31].”
BackgroundMethodSelf-citationCalcium transport in male reproduction is possibly influenced by vitamin D and CaSR.
Boisen, I., Nielsen, J., Verlinden, L., Lorenzen, M., Holt, R., Pinborg, A., Andreassen, C., Juul, A., Lanske, B., Carmeliet, G., et al. (2021) · Journal of Endocrinology · doi:10.1530/joe-20-0321 · Cited by 14
Self-citationMichaelsen, M. P., Poulsen, M., Bjerregaard, A. A., Borgstrøm, M. B., Poulsen, L., Chortsen, M., Henriksen, S., & Kesmodel, U. S. (2025) · Nutrients · doi:10.3390/nu17101710 · Cited by 15 · see citing works
“Four studies reported improvements in most or all sperm parameters [31–33, Four studies reported improvements in most or all sperm parameters [31–33”
Simpson, S., & Pal, L. (2023) · Current Opinion in Obstetrics & Gynecology · doi:10.1097/gco.0000000000000887 · Cited by 13 · see citing works
Holt, R., Yahyavi, S., Kooij, I., Andreassen, C., Andersson, A., Juul, A., Jørgensen, N., & Jensen, M. B. (2023) · BMC Medicine · doi:10.1186/s12916-023-02782-1 · Cited by 13
Self-citationAsadpour, R., Taravat, M., Rahbar, M., Khoshniyat, M., & Hamidian, G. (2021) · Basic and Clinical Andrology · doi:10.1186/s12610-021-00137-5 · Cited by 13
“[30] showed Table 1 Effect of supplementation of semen extender with different concentration of vitamin D on frozen–thawed spermatozoa kinematics in normozoopsermic and asthenozoopsermic Holstein bulls”
Association of Vitamin D and Reproductive Hormones With Semen Parameters in Infertile Men
Kumari, S., Singh, K., Kumari, S., Nishat, H., & Tiwary, B. (2021) · Cureus · doi:10.7759/cureus.14511 · Cited by 13
“However, another study showed that vitamin D supplementation did not affect semen parameters in oligoasthenozoospermic men, but showed that the rate of spontaneous pregnancies and chance for a live birth were increased compared with the placebo group [28].”
Patki, A. S., Shelatkar, R., Singh, M., Agarwal, S., Venugopal, M., Umbardand, S., Reddy, A., Kannan, P., Gorthi, S., Khastgir, G., et al. (2023) · Translational and Clinical Pharmacology · doi:10.12793/tcp.2023.31.e6 · Cited by 16 · see citing works
Tania, C., Tobing, E., Tansol, C., Prasetiyo, P. D., Wallad, C., & Hariyanto, T. (2023) · Arab Journal of Urology · doi:10.1080/2090598x.2023.2165232 · Cited by 12 · see citing works
Pooladi, M., Sharifi, M., Abbasi, Y., & Dashti, G. (2022) · Advanced Biomedical Research · doi:10.4103/abr.abr_261_21 · Cited by 12 · see citing works
Compromised Activation of Vitamin D After Elective Surgery: A Prospective Pilot Study
Jensen, M. B., Husted, H., Bjerrum, P. J., Juul, A., & Kehlet, H. (2018) · JBMR Plus · doi:10.1002/jbm4.10053 · Cited by 14 · see citing works
Self-citationHansen, L. B., Lorenzen, M., Bentin-Ley, U., Nielsen, J., Krog, H., Berg, A., Håkansson, B., Pedersen, A. M., Høst, T., Juul, A., et al. (2019) · Journal of Steroid Biochemistry and Molecular Biology · doi:10.1016/j.jsbmb.2019.04.002 · Cited by 11
Self-citationAll Properties of Infertility Microbiome in a Review Article
Elahi, Z., Mokhtaryan, M., Mahmoodi, S., Shahroodian, S., Darbandi, T., Ghasemi, F., Ghanavati, R., & Darbandi, A. (2025) · Journal of Clinical Laboratory Analysis · doi:10.1002/jcla.25158 · Cited by 13 · see citing works
25(OH)VitD and human endocrine and functional fertility parameters in women undergoing IVF/ICSI
Tian, M., Zeng, S., Cai, S., Reichetzeder, C., Zhang, X., Yin, C., Kuang, W., Cheng, K., Jiang, Y., Tao, M., et al. (2022) · Frontiers in Endocrinology · doi:10.3389/fendo.2022.986848 · Cited by 7 · see citing works
Antioxidants for male subfertility.
de Ligny, W. D., Smits, R., Mackenzie-Proctor, R., Jordan, V., Fleischer, K., de Bruin, J., & Showell, M. (2022) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd007411.pub5 · Cited by 10 · see citing works
Vitamin D status is heritable and under environment‐dependent selection in the wild
Sparks, A., Johnston, S., Handel, I., Pilkington, J., Berry, J., Pemberton, J., Nussey, D., & Mellanby, R. (2020) · bioRxiv · doi:10.1111/mec.16318 · Cited by 10 · see citing works
Is vitamin D status reflected by testosterone concentration in elite athletes?
Krzywański, J., Pokrywka, A., Młyńczak, M., & Mikulski, T. (2020) · Biology of Sport · doi:10.5114/biolsport.2020.95633 · Cited by 13 · see citing works
“There is some evi - dence of the positive influence of vitamin D status on sperm motili - ty [83, 84], as well as the effect of its supplementation on semen quality and male fertility [85, 86].”
BackgroundGlobal Andrology Forum Clinical Guidelines on Antioxidant Use in the Treatment of Male Infertility.
Agarwal, A., Mostafa, T., Hashimi, M. A., Çayan, S., Pescatori, E., Singh, K., Şahin, B., Zini, A., Chung, E., Arafa, M., et al. (2026) · The World Journal of Men's Health · doi:10.5534/wjmh.250290 · Cited by 9 · see citing works
Denosumab stimulates spermatogenesis in infertile men with preserved Sertoli cell capacity
Andreassen, C. H., Holt, R., Mortensen, L. J., Knudsen, N. K., Nielsen, J. E., Poulsen, N. N., Yahyavi, S. K., Boisen, I. M., Cui, Z., Ongaro, L., et al. (2024) · Cell Reports Medicine · doi:10.1016/j.xcrm.2024.101783 · Cited by 12 · see citing works
“17 In an exploratory post hoc analysis of a subgroup of men with serum AMH R 38 pmol/L at baseline (corresponding to 41% of all men), a significantly higher sperm concentration (5 million/mL) was observed in individuals treated with denosumab compared with placebo.”
Self-citationVitamin D Levels and Risk of Male Factor Infertility: A Mendelian Randomization Study
Chi, Y., Xiang, L., Jian, Z., & Liao, B. (2023) · The World Journal of Men s Health · doi:10.5534/wjmh.220109 · Cited by 9 · see citing works
“The results of this MR study support the protective role of VD in MFI, which complements the previous RCTs. Blomberg Jensen’s team found no significant improvement in sperm parameters in VD deficient men ( 25 nmol/L, n=66) treated with VD [12].”
InfluentialLeo, V. D., Tosti, C., Morgante, G., Ponchia, R., Luddi, A., Governini, L., & Piomboni, P. (2022) · Journal of Clinical Medicine · doi:10.3390/jcm11071991 · Cited by 8 · see citing works
Krog, M. C., Madsen, M. E., Bliddal, S., Bashir, Z., Vexø, L. E., Hartwell, D., Hugerth, L. W., Fransson, E., Hamsten, M., Boulund, F., et al. (2022) · Human Reproduction Open · doi:10.1093/hropen/hoac015 · Cited by 13 · see citing works
“…..DNA integrity based on the sperm chromatin structure assay) test (Blomberg Jensen et al., 2018) and the COMET (microgel electrophoresis technique) assay or TUNEL assay (terminal deoxynucleotidyl transferase dUTP nick-end…”
[Vitamin D and reproductive health].
Gorelova, I., Popova, P., & Rulev, M. V. (2020) · Problemy Endokrinologii · doi:10.14341/probl12468 · Cited by 9
The Impact of Vitamin D on Androgens and Anabolic Steroids among Adult Males: A Meta-Analytic Review
Abu-Zaid, A., Saleh, S. A. K., Adly, H. M., Baradwan, S., Alharran, A. M., Alhatm, M., Alzayed, M. M., Alotaibi, M. N., Saad, A. R., Alfayadh, H. M., et al. (2024) · Diseases · doi:10.3390/diseases12100228 · Cited by 11 · see citing works
Humla, E. C., Bergh, C., Akouri, R., & Tsiartas, P. (2022) · Human Reproduction Open · doi:10.1093/hropen/hoac036 · Cited by 8
“…secretion and vitamin D synthesis, all important parameters for the reproductive efficacy (Kauppila et al., 1987; Lam and Miron, 1991; Rojansky et al., 1992; Reiter, 1993; Levine, 1994; Bronson, 1995; Levine, 1999; Cummings, 2003, 2007, 2010a,b; Reiter et al., 2014; Blomberg Jensen et al., 2018).”
BackgroundYahyavi, S., Holt, R., Mortensen, L. J., Petersen, J., Jørgensen, N., Juul, A., & Jensen, M. B. (2022) · Trials · doi:10.1186/s13063-022-06478-4 · Cited by 8
Self-citationEffect of Vitamin D3 Supplement on the Semen Quality in Human Patients with Vitamin D Deficiency
Abed, H. H., Ali, A. M., & Mahdi, Z. S. (2022) · HAYATI Journal of Biosciences · doi:10.4308/hjb.29.5.562-569 · Cited by 8 · see citing works
“The findings of this study corroborate with those of prior studies that have found a specific role for vitamin D in sperm motility (Blomberg Jensen et al. 2018).”
ResultVitamins as primary or adjunctive treatment in infertile men with varicocele: A systematic review
Tsampoukas, G., Gkeka, K., Dellis, A., Brown, D., Katsouri, A., Alneshawy, A., Moussa, M., Papatsoris, A., & Buchholz, N. (2021) · Arab Journal of Urology · doi:10.1080/2090598x.2021.1932124 · Cited by 8 · see citing works
Tiosano, D., Abrams, S., & Weisman, Y. (2021) · Journal of NutriLife · doi:10.1093/jn/nxaa380 · Cited by 7
Holzer, M., Massa, E., & Ghersevich, S. A. (2022) · Current Urology · doi:10.1097/cu9.0000000000000075 · Cited by 8 · see citing works
“[44] In conclusion, our results suggest that vitD could affect male reproductive function and that its deficiency may be related to infertility.”
BackgroundMortensen, L. J., Lorenzen, M., Jørgensen, A., Albrethsen, J., Jørgensen, N., Møller, S., Andersson, A., Juul, A., & Jensen, M. B. (2021) · Cancers · doi:10.3390/cancers13061329 · Cited by 8 · see citing works
“The Copenhagen-Bone-Gonadal Study is a cohort of 307 infertile men with no serious co-morbidities referred from 2011 to 2015 to our andrological outpatient clinic and included a total of 1427 men [21,22].”
BackgroundMethodSelf-citationChen, Y.-L., Liu, D.-F., Zeng, L., Xu, H.-Y., Jiang, H., Yang, R., Wang, H.-N., Yan, L.-Y., Li, R., Qiao, J., et al. (2020) · Andrology · doi:10.1111/andr.12818 · Cited by 6
Yahyavi, S. K., Wall-Gremstrup, G., Probst-Drejer, B., Toft, F. B., Jorsal, M. J., Holt, R., Aksglæde, L., Jørgensen, N., Juul, A., & Jensen, M. B. (2024) · Human Reproduction · doi:10.1093/humrep/deae293 · Cited by 7 · see citing works
Self-citationPreconceptual care for couples seeking fertility treatment, an evidence-based approach
Chronopoulou, E., Seifalian, A., Stephenson, J., Serhal, P. F., Saab, W., & Seshadri, S. (2020) · F&S Reviews · doi:10.1016/j.xfnr.2020.09.001 · Cited by 5 · see citing works
Vitamin D receptor expression in sperm of males with unexplained infertility.
Sagheb, Z. A., Mohammadnia‐Afrouzi, M., Shafi, H., Esmailzadeh, S., Ganji, K. S., & Shahbazi, M. (2023) · PubMed Central · doi:10.22088/cjim.14.1.94 · Cited by 4 · see citing works
Lengyel, B., Armos, R., Bojtor, B., Kiss, A., Tóbiás, B., Pikó, H., Illés, A., Horvath, E. M., Putz, Z., Takács, I., et al. (2025) · Pharmaceuticals · doi:10.3390/ph19010054 · Cited by 3 · see citing works
“Another consistent result was that vitamin D levels show a positive correlation with fertility, with infertile men having considerably lower vitamin D levels [209,210,212].”
The Intimate Relationship between Adipose Tissue, Fertility, and Bone
Michalopoulou, O., Kostoglou-Athanassiou, I., Troupis, G. T., & Mastorakos, G. (2026) · Journal of Frailty, Sarcopenia and Falls · doi:10.22540/jfsf-11-080 · Cited by 3
“Low serum 25(OH)D is associated with reduced sperm count and motility in population studies, while supplementation modestly improves reproductive hormones and semen parameters in men with such deficiency 102,103 .”
Saberivand, A., Sarvarzadeh, F., Peighambarzadeh, S., Saberivand, M., Pakizehvand, H., Rashidi, S., Rahbar, M., & Khoshniyat, M. (2022) · Theriogenology · doi:10.1016/j.theriogenology.2022.06.017 · Cited by 3
Reproductive history of patients with hereditary 1,25-dihydroxyvitamin D–resistant rickets
Tiosano, D., & Weisman, Y. (2019) · Fertility and Sterility · doi:10.1016/j.fertnstert.2019.02.028 · Cited by 5 · see citing works
Melhem, S. J., Melhem, M., Haddad, R., Alghurabi, O., Mousa, R., Massad, E. M., Almomani, H., Alrashdan, Y., & Melhem, J. (2026) · Andrology · doi:10.1111/andr.70266 · Cited by 2 · see citing works
“Jensen et al. [ 24 ] enrolled 330 infertile men with baseline vitamin D insufficiency and randomized them to cholecalciferol with calcium or placebo for 5 months.”
InfluentialYahyavi, S. K., Toft, F. B., Probst-Drejer, B., Boisen, I. M., Priskorn, L., Jørgensen, N., Juul, A., & Jensen, M. B. (2026) · Andrology · doi:10.1111/andr.70172 · Cited by 2 · see citing works
“Second, many of the screened men for the RCT were not eligible to participate in the study due to exclusion criteria [ 24 ], which could limit generalizability to other studies.”
InfluentialSelf-citationWen, Q., Xu, H.-Y., Zou, H., Wang, P., Xing, X., Chen, Y., Zhu, Q.-L., Chen, Y., Tan, M.-H., Zhang, M.-M., et al. (2024) · Frontiers in Endocrinology · doi:10.3389/fendo.2024.1418936 · Cited by 2 · see citing works
Dialameh, H., Nikoobakht, M., Oskouie, I. M., Rahimdoost, N., Nazarpour, M., Mousavi, S. H., Lotfi, M., Esmaeilpanah, S., & Inanloo, H. (2023) · Urologiâ · doi:10.1177/03915603231162394 · Cited by 2
Effect of Adding Different Vitamin D3 Concentrations on Chilled Storage of Awassi Ram Semen
Bresm, M. H. A., & Habeeb, H. M. H. (2022) · IOP Conference Series: Earth and Environment · doi:10.1088/1755-1315/1060/1/012084 · Cited by 2
“However, This is in contrast to the study conducted by [36] who reported that a low level of VD decreases sperm motility.”
ResultRole of vitamin D in common urological conditions: a narrative review of past decade literature
Brown, D., Gkeka, K., Narayan, Y., Katsouri, A., Tsampoukas, G., & Buchholz, N. (2021) · Longhua Chinese Medicine · doi:10.21037/lcm-21-49 · Cited by 2
“Notably, treatment with vitamin D has also been associated with higher live-birth rates in couples in which the man had oligozoospermia compared with those men taking placebo (77).”
BackgroundImpact of Vitamin D on Male Iraqi Patients with Infertility
Aziz, A. S. A., Al-Sharifi, Z. A. R., & Dulaime, H. K. A. (2020) · Annals of Tropical Medicine and Public Health · doi:10.36295/asro.2020.232240 · Cited by 2
The effect of lipid disturbance and vitamin D on the fertility in male albino rats
Hikal, S. M., Bayoumi, M. E., Ibrahim, S. E., & el Shawwa, M. (2020) · Journal of Recent Advances in Medicine/Journal of Recent Advances in Medicine · doi:10.21608/jram.2020.30036.1058 · Cited by 2 · see citing works
Medikamentöse Therapie primär nichthormonell bedingter männlicher Fertilitätsstörungen
Haidl, G., Allam, J., Köhn, F., Haidl, F., & Schuppe, H. (2019) · Gynäkologische Endokrinologie · doi:10.1007/s10304-019-00273-2 · Cited by 2
Zhang, G., Nelli, G., Hoe, S., & Hamdan, M. (2026) · PeerJ · doi:10.7717/peerj.21002 · Cited by 1 · see citing works
“The study by Blomberg Jensen et al. (2018) , contributing 98.2% of the weight, showed the most precise effect estimate.”
InfluentialYahyavi, S., Holt, R., Jorsal, M., Árting, L. B., Eldrup, E., Juul, A., Jørgensen, N., & Jensen, M. B. (2024) · Journal of Steroid Biochemistry and Molecular Biology · doi:10.1016/j.jsbmb.2024.106640 · Cited by 1
“This study utilizes secondary outcome data from a previously conducted randomized clinical trial [19] to describe and compare the association of serum levels of total 25OHD, free 25OHD, and free 25OHD % on various calciotropic, bone, and metabolic outcomes.”
Self-citationLi, N.-N., Yang, K., Zeng, Y., Cao, S., & Deng, L. (2024) · Reproductive Toxicology · doi:10.1016/j.reprotox.2024.108597 · Cited by 1
Decline in human sperm parameters: How to stop?
Mohamed, E. A. (2023) · Clinical Journal of Obstetrics and Gynecology · doi:10.29328/journal.cjog.1001122 · Cited by 1
Highlights from the 22nd Workshop on Vitamin D in New York City, May 2019.
Fleet, J., Bernal-Mizrachi, C., Hewison, M., Jorde, R., White, J. H., Cantorna, M., Schoenmakers, I., & Erben, R. (2020) · Journal of Steroid Biochemistry and Molecular Biology · doi:10.1016/j.jsbmb.2020.105747 · Cited by 1 · see citing works
JawdatKadhim, M., & Al-Dabbagh, A. (2020) · doi:10.36295/asro.2020.231805 · Cited by 1
“Calcium is needed to commence the acrosome reaction liberating enzymes necessary for effective sperm-ovum communication (18) , and vitamin D through activation of VDR raised the intracellular calcium from its store in the sperm’s neck stimulating sperm motility and acrosome reaction (19), therefore calcium action on m…”
BackgroundResultInfluentialAssessment of Sperm DNA Integrity and Implications for the Outcome of ICSI Treatments
Christensen, P., & Birck, A. (2018) · Springer eBooks · doi:10.1007/978-3-319-70497-5_6 · Cited by 1 · see citing works
Filho, D. R., Nogueira‐de‐Almeida, C. A., & Filho, A. E. D. O. (2019) · International Journal of Nutrology · doi:10.1055/s-0040-1709661 · Cited by 8 · see citing works
Sengupta, P., Dutta, S., Alaee, S., Mishra, D., Selvam, M. K. P., Rosas, I. M., & Roychoudhury, S. (2026) · Frontiers in Veterinary Science · doi:10.3389/fvets.2026.1920393
Vitamin D in male reproduction: molecular mechanisms and pharmacological perspectives
Liu, J., Liu, B., Qiu, X.-Y., Lv, M.-M., Liu, S.-S., & Zhou, D. (2026) · Frontiers in Pharmacology · doi:10.3389/fphar.2026.1849299
Puia, D., Ivănuță, M., Corlade-Andrei, M., Tory, H., Majeru, A.-G., Doroftei, B., Ștefăniu, R., Elena, V., & Pricop, C. (2026) · Endocrines · doi:10.3390/endocrines7030051
Nazarpour, M., Hamidi, M., Gholipour, F., Dialameh, H., Dehaki, M. G., Kazemi-Galougahi, M., & Namdari, F. (2026) · Journal of Research in Medical Sciences · doi:10.4103/jrms.jrms_1064_25
The 24,25(OH)2D3-TLCD3B signaling complex and reproductive function in mice and men
Kooij, I., Mitrofanov, K., Rehfeld, A., Andreassen, C. H., Madsen, S. K., Janssen, A. M., St‐Arnaud, R., Jørgensen, A., & Jensen, M. B. (2026) · The Journal of Steroid Biochemistry and Molecular Biology · doi:10.1016/j.jsbmb.2026.107060
- Authors
- Blomberg Jensen, M., Lawaetz, J. G., Petersen, J. H., Juul, A., & Jørgensen, N.
- Affiliations
- Department of Growth and Reproduction, International Research and Research Training Centre in Endocrine Disruption of Male Reproduction and Child Health, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- University of Copenhagen (DK)
- Venue
- The Journal of Clinical Endocrinology & Metabolism
- Publisher
- The Endocrine Society
- Published
- 2017-11-03
- Volume
- 103
- Issue
- 3
- Pages
- 870-881
- ISSN
- 0021-972X (ISSN-L)
- 1945-7197
- OpenAlex
- W2766252936
- Cited by
- 129
- References
- 35
- Citations by year
- 2026: 10 · 2025: 15 · 2024: 15 · 2023: 17 · 2022: 17 · 2021: 16 · 2020: 17 · 2019: 15 · 2018: 7
- FWCI
- 12.42
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- The Journal of Clinical Endocrinology & Metabolism (publishedVersion)
- PubMed (publishedVersion)
- Research at the University of Copenhagen (University of Copenhagen) (submittedVersion)
- Funders
- Hørslev-Fonden
- Novo Nordisk
- Novo Nordisk Fonden (NNF17OC0026096)
- Topics
- Health Sciences › Medicine › Reproductive Medicine › Sperm and Testicular Function
- Health Sciences › Medicine › Pathology and Forensic Medicine › Vitamin D Research Studies
- Health Sciences › Health Professions › General Health Professions › Male Reproductive Health Studies
- Keywords
- vitamin D supplementation, vitamin D3, calcium supplementation, male infertility, semen quality, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D3, inhibin B, live birth rate, oligozoospermia, vitamin D deficiency, male reproductive hormones
- MeSH terms
- Adult, Calcium, Cholecalciferol, Double-Blind Method, Drug Therapy, Combination, Female, Humans, Infertility, Male, Male, Middle Aged, Oligospermia, Pregnancy, Pregnancy Outcome, Sperm Count, Sperm Motility, Vitamin D, Vitamin D Deficiency, Pregnancy Rate, Dietary Supplements, Semen Analysis
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