Longitudinal hormonal dynamics during minipuberty and exploratory associations with vitamin D status in healthy term male infants

Introduction and aim. Minipuberty, the transient postnatal reactivation of the hypothalamic-pituitary-gonadal axis, is a critical window for male reproductive maturation. The study prospectively characterized hormonal dynamics during minipuberty and explored associations between 25-hydroxyvitamin D [25(OH)D] and gonadal hormones, adrenal corticosterone, and genital growth parameters. Material and methods. Sixty healthy term male babies were enrolled; 52 completed follow-up. Testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), corticosterone, and 25(OH)D were measured on day 3 and at 3 months by LC-MS/MS and chemiluminescence immunoassay. Penile length and testicular volume were recorded at both visits. Results. Testosterone increased from 47.18 to 142.62 ng/dL, LH from 1.31 to 2.46 mIU/mL, and FSH from 1.22 to 2.10 mIU/L (all p<0.001), while corticosterone decreased from 211.19 to 86.25 ng/dL (p<0.001). Several nominal associations were observed before multiple comparison correction; however, after Bonferroni correction, only the inverse association between 25(OH)D and corticosterone at 3 months (r=−0.576, p<0.001) remained statistically significant. All other associations should be considered exploratory. Conclusion. Only the inverse association between vitamin D and corticosterone remained statistically significant after correction, while other associations were exploratory and require confirmation in larger studies.