Vitamin D Supplementation and Male Infertility: The CBG-study a Randomized Clinical Trial
Status:
Completed
Trial end date:
2016-05-01
Target enrollment:
Participant gender:
Summary
Today, it is evident that vitamin D (VD) has more widespread effects than the classical
actions related to bone mineralization and calcium homeostasis1. VD deficiency results in
impaired reproductive performance in various species of animals, and recently the
investigators have shown that the VD receptor (VDR), activating (CYP2R1, CYP27A1, CYP27B1)
and inactivating (CYP24A1) enzymes are expressed in the human testis, epididymis, seminal
vesicle, prostate and spermatozoa. Our following functional studies showed that VD increases
intracellular calcium in mature spermatozoa, and hence may be important not only for
spermatogenesis but also for sperm maturation. A new, and yet unpublished cross sectional
study of 300 young healthy Danish men showed that men with lower levels of serum VD have
significantly lower number of normally developed and motile spermatozoa. Hitherto, most cases
of male infertility have been classified as "idiopathic", and infertile couples have been
referred to symptomatic treatment at infertility clinics. These fertility treatments are
often physically demanding for the female partner as well as expensive for the health care
system. Any treatment that might improve semen quality of involuntary infertile men would be
beneficial both for the infertile couples and the society in general. Our findings that VD
may play a role for human semen quality have not yet been tested clinically. However, if VD
supplementation proves efficient this opens for the first time for a causal, safe and cheap
treatment of at least some cases of "idiopathic" impaired semen quality. The investigators
believe our new human data supported by the results from the VD deficient and VDR KO animal
studies and the high proportion of VD deficient Danish men provide sufficient evidence to
initiate a randomized clinical trial of VD supplementation to infertile men. Infertile men
have also have unfavorable altered levels of sex hormones and higher mortality than fertile
men. Since VD deficiency is associated with increased mortality, regulation of aromatase,
immune system, bone metabolism, glucose metabolism, cardiovascular system etc. our suggested
clinical trial may also be able to evaluate several secondary endpoints in addition to the
potential effect on semen quality.
Phase:
Phase 2/Phase 3
Details
Lead Sponsor:
Rigshospitalet, Denmark
Treatments:
Calcium Calcium, Dietary Cholecalciferol Ergocalciferols Vitamin D Vitamins