Vitamin D and sex steroid production in men with normal or impaired Leydig cell function

In conclusion, vitamin D deficiency is associated with lower testosterone/estradiol ratio in young men and lower Leydig cell sensitivity after hCG-stimulation in men with impaired gonadal function. The significant effect of 1,25(OH)2D3 on testosterone production in a human testis model supports that the stimulatory effect at least in part may be direct. Larger placebo-controlled studies are needed to determine whether vitamin D supplementation can influence testosterone production.
Source: The Journal of Steroid Biochemistry and Molecular Biology - Category: Biochemistry Source Type: research