Inhibin-B
Difference in serum levels of Inhibin B between placebo and VD group after 90 and/or 150 days
Testosterone
Difference in serum levels of total and free testosterone between placebo and VD group after 90 and/or 150 days
AMH
Difference in serum levels of anti-müellerian hormone (AMH) between placebo and VD group after 90 and/or 150 days
estrogen
Difference in serum levels of estrogen (estradiol) between placebo and VD group after 90 and/or 150 days
LH
Difference in serum levels of lh (luteinizing hormone) between placebo and VD group after 90 and/or 150 days
FSH
difference in FSH (follicle stimulating hormone) between placebo and VD group after 90 and/or 150 days
SHBG
difference in SHBG (sex hormone binding hormone) between placebo and VD group after 90 and/or 150 days
DXA scan
difference in fat mass, fat free mass, muscle mass and bone mineral density evaluated by full body DXA scan between placebo and VD group after 150 days
Circulating metabolites of Vitamin D
difference in the following VD metabolites inactive VD2 and VD3,25-hydroxy-VD2, 25-hydroxy-VD3, 1,25(OH)2D3, 24,25(OH)2D3, and 1,24,25(OH)2D3 between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
PTH
difference in the following serum levels of PTH (parathyroid hormone between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
alkaline phosphatase
difference in the following serum levels of alkaline phosphatase (also bone specific subtype) between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
calcium
difference in the following serum levels of calcium ( meaning total calcium, calcium ion and albumin corrected calcium) between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
phosphate
difference in the following serum levels of phosphate between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
FGF23
difference in the following serum levels of FGF23 (both intact and fragmented) between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
Klotho
difference in the following serum levels of klotho (also subtypes) between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
osteocalcin
difference in the following serum levels of osteocalcin between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
osteopontin
difference in the following serum levels of osteopontin between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
Rank-L
difference in the following serum levels of Rank-L between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
calcitonin
difference in the following serum levels of calcitonin between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
bone markers
difference in the following serum levels of bone markers such as procollagen III between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
change in the method of assisted reproductive technique or number of pregnancies
difference in the type of method used IUI, IVF, ICSI and in the number of achieved pregnancies between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
change in the number of spontaneous pregnancies
difference in the number of spontaneous achieved pregnancies between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
blood pressure
difference in systolic and/or diastolic blood pressure between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
CYP24A1 expression at the annulus
difference CYP24A1 expression at the annulus of human spermatozoa between placebo and VD group after 150 days and between the initial level (day 0) and 150 days in both arms.
Bone and calcium regulators in seminal fluid
difference in seminal fluid concentration of pH, HCO3-, calcium, zinc, phosphate, VD, 1,25(OH)2D3, 25-OHD3, 24,25(OH)2D3, 1,24,25(OH)2D3, FGF23, Klotho, osteocalcin, osteopontin between placebo and VD group after 150 days and between the initial level (day 0) and 150 days in both arms.
weight and BMI
difference in weight and BMI between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
Glucose metabolism
difference in serum level of glucose, Hb1Ac, cholesterol, lipid profile, insulin, leptin, adiponectin, C-peptid, HOMA, insulin sensitivity, incretin hormones (such as GLP1 and 2)between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
Growth and IGF axis
difference in serum level of GH, IGF-I, IGFBP-3 between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
tumor markers
difference in PSA (prostate specific antigen both free and bound) and CEA ( carcino embryonic antigen)between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
stress hormones
difference in serum level of cortisol, ACTH and copeptin between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
prolactin
difference in serum level of prolactin between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
kidney and cardiovascular markers
difference in serum level of creatinin, albumin, urea, urea acid (urat), creatinine clearance, renin, aldosteron, angiotensinogen, B2-microglobulin, and angiotensin 2 between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
liver markers
difference in serum level of aminotransferases (ALAT, ASAT, GGT), LDH, amylase, bilirubin between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
infectious disease
difference in frequency and severity of infectious diseases such as cold, sinusitis, tonsillitis, laryngitis, pneumonia, UVI, gastroenteritis, skin infections. between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
fever
difference in frequency and severity of fever episodes between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
inflammatory markers
difference in the following serum levels of acute phase reactants such as CRP (C reactive peptide), Ferritin, procalcitonin, leukocytes, thrombocytes, reticulocytes, RBC, haematocrit, complement, immunoglobulins, auto-antibodies such as ANA, antiphopholipantibody, rheumafactor and coagulation factors between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
natriuretic peptides
difference in the following serum levels of ANP and BNP between placebo and VD group after 90 and/or 150 days and between the initial level (day 0) and 90 and 150 days in both arms.
DNA Fragmentation
DNA fragmentation index will be investigated on 75-100 randomly selected individuals prior to and following the intervention with either placebo or vitamin D
Predefined Subgroup analyses
Predefined subgroups. Vitamin D levels: a. deficient< 25 nM, b. insufficient 25-50 nM Season: a. Winter, b. spring, c. summer and d. autumn or x. Winter(October-March)and y.Summer(April to September) Serum calcium ion: a. =/<1.20 nM , b. > 1.20 nM Sperm concentration: a. < 5 million/ml, b. 5-20 million/ml,c. > 20 million/ml Inhibin B: a. < 100 pg/ml ,b. 100-150 pg/ml, c. > 150 pg/ml BMI: a. < 25 , b. 25-30, c. > 30 Cryptorchidism: a. YES/NO