TY - JOUR
T1 - High Seminal Fluid Calcium Is Associated With Higher Sperm Concentration in Infertile Men and Men From the General Population
AU - Yahyavi, Sam Kafai
AU - Toft, Frederikke Bay
AU - Probst-Drejer, Benedicte
AU - Boisen, Ida Marie
AU - Priskorn, Lærke
AU - Jørgensen, Niels
AU - Juul, Anders
AU - Blomberg Jensen, Martin
N1 - © 2026 American Society of Andrology and European Academy of Andrology.
PY - 2026/1/14
Y1 - 2026/1/14
N2 - BACKGROUND: The extracellular calcium concentration is important for sperm function, maturation, and survival, however, studies exploring the link between seminal calcium and reproductive function have reported inconsistent findings.OBJECTIVES: To investigate the association between seminal calcium levels and semen quality in both healthy and infertile men.MATERIALS AND METHODS: A total of 301 young men from the general Danish population who participated in a study of semen quality, and 228 infertile men who were supplemented with calcium (500 mg) + cholecalciferol (300,000 IU bolus followed by 1400 IU daily), or placebo in a randomized controlled trial were included. Each man underwent a physical examination, routine semen analysis, analysis of calcium concentrations in the seminal fluid, and blood sampling for assessment of PTH, testosterone, estradiol, inhibin B, and AMH.RESULTS: In young men from the general population, sperm concentration was higher in those within the highest seminal calcium quartile (Q4: 9.0-19.2 mmol/L) compared with the lowest (Q1: 1.3-4.7 mmol/L; 53.0 million/mL vs. 31.0 million/mL, p = 0.010). Accordingly, infertile men in Q1 had the lowest sperm concentration (e.g., 6.6 vs. 22.5 million/mL in Q3), but also fewer progressively motile spermatozoa (p = 0.030). Supplementation with calcium and cholecalciferol did not affect seminal calcium concentration (p = 0.33), however, infertile men who experienced an increase in their seminal calcium concentrations > 30% at the end of intervention had a higher sperm concentration (p = 0.048) and total sperm count (p < 0.001) compared with baseline. There was a weak positive correlation between longitudinal changes of seminal calcium and serum estradiol (r = 0.17, p = 0.016).CONCLUSIONS: Lower seminal calcium concentration is associated with poorer semen quality but was not influenced by calcium supplementation. Future research should focus on uncovering possible regulators, for instance, estrogens.TRIAL REGISTRATION: ClinicalTrials.gov no. NCT01304927 (registered February 28, 2011).
AB - BACKGROUND: The extracellular calcium concentration is important for sperm function, maturation, and survival, however, studies exploring the link between seminal calcium and reproductive function have reported inconsistent findings.OBJECTIVES: To investigate the association between seminal calcium levels and semen quality in both healthy and infertile men.MATERIALS AND METHODS: A total of 301 young men from the general Danish population who participated in a study of semen quality, and 228 infertile men who were supplemented with calcium (500 mg) + cholecalciferol (300,000 IU bolus followed by 1400 IU daily), or placebo in a randomized controlled trial were included. Each man underwent a physical examination, routine semen analysis, analysis of calcium concentrations in the seminal fluid, and blood sampling for assessment of PTH, testosterone, estradiol, inhibin B, and AMH.RESULTS: In young men from the general population, sperm concentration was higher in those within the highest seminal calcium quartile (Q4: 9.0-19.2 mmol/L) compared with the lowest (Q1: 1.3-4.7 mmol/L; 53.0 million/mL vs. 31.0 million/mL, p = 0.010). Accordingly, infertile men in Q1 had the lowest sperm concentration (e.g., 6.6 vs. 22.5 million/mL in Q3), but also fewer progressively motile spermatozoa (p = 0.030). Supplementation with calcium and cholecalciferol did not affect seminal calcium concentration (p = 0.33), however, infertile men who experienced an increase in their seminal calcium concentrations > 30% at the end of intervention had a higher sperm concentration (p = 0.048) and total sperm count (p < 0.001) compared with baseline. There was a weak positive correlation between longitudinal changes of seminal calcium and serum estradiol (r = 0.17, p = 0.016).CONCLUSIONS: Lower seminal calcium concentration is associated with poorer semen quality but was not influenced by calcium supplementation. Future research should focus on uncovering possible regulators, for instance, estrogens.TRIAL REGISTRATION: ClinicalTrials.gov no. NCT01304927 (registered February 28, 2011).
KW - infertility
KW - randomized controlled trial
KW - semen quality
KW - seminal calcium
KW - vitamin D
UR - http://www.scopus.com/inward/record.url?scp=105027668739&partnerID=8YFLogxK
U2 - 10.1111/andr.70172
DO - 10.1111/andr.70172
M3 - Journal article
C2 - 41531256
SN - 2047-2919
SP - e70172
JO - Andrology
JF - Andrology
ER -