A-ED	Arteriogenic ED
BL-ED	Borderline ED
BMI	Body mass index
CMIA	Chemiluminescence microparticle immunoassay
CVD	Cardiovascular disease
ECD	Echo-color-Doppler.
ED	Erectile dysfunction
FSH	Follicle-stimulating hormone
IIEF	International Index of Erectile Function
LC–MS/MS	Liquid chromatography tandem mass spectrometry
LH	Luteinizing hormone
LUTS	Lowe urinary tract symptoms
NPTR	Nocturnal penile tumescence and rigidity
MMAS	Massachusetts Male Aging Study
MeSH	Medical Subjects Headings
NA-ED	non-arteriogenic ED
SHIM	Sexual Health Inventory for Men
UK	United Kingdom
VD	vitamin D
25(OH)D	25-hydroxy-vitamin-D