Vitamin D deficiency is associated with an increased prevalence of erectile dysfunction (ED) independent of risk factors for atherosclerotic cardiovascular disease (ASCVD), according to a new study.
Men with vitamin D deficiency—defined as a 25-hydroxyvitamin D [25(OH)D] level below 20 ng/mL—have a significant 30% and 80% greater prevalence of ED and severe ED, respectively, compared with men who have optimal levels (30 ng/mL or higher), after adjusting for comorbidities, lifestyle variables, and medication use, investigators reported in Atherosclerosis (2016;252:61-67). In addition, each 10 ng/mL decrease in 25(OH)D was associated with a significant 12% increased prevalence of ED.
“Our findings have potentially important clinical and public health implications for men,” Erin D. Michos, MD, of Johns Hopkins University School of Medicine in Baltimore, and colleagues wrote. “25(OH)D is an easy biomarker to screen for through simple commercially-available laboratory tests, and deficiencies can be treated with supplementation and/or modest sunlight exposure.”
They pointed out, however, that additional research, such as randomized controlled clinical trials, is needed to determine whether treating vitamin D deficiency can improve erectile function.
Dr Michos’ team studied 3390 men aged 20 years or older free of ASCVD who participated in the 2001–2004 National Health and Nutrition Examination Survey. For the study, investigators measured serum 25(OH)D using the DiaSorin radioimmunoassay and assessed self-reported ED using a single question from the Massachusetts Male Aging Study: “How would you describe your ability to get and keep an erection adequate for satisfactory intercourse?” Men who answered “never” or “sometimes able” were considered to have ED. Investigators defined severe ED as never being able to get and keep an erection.
The weighted prevalence of 25(OH)D deficiency and ED were 30% and 15.2%, respectively. Levels of 25(OH)D were significantly lower among men with versus without ED (mean 22.8 vs 24.3 ng/mL).
Dr Michos and her colleagues discussed various mechanisms that could explain a biologic relationship between vitamin D deficiency and ED. For example, vascular ED results from endothelial dysfunction and/or atherosclerosis. Diabetes mellitus is a strong risk factors for both of these conditions, diabetic men are 3 times more likely than non-diabetic men to have ED, they pointed out. “The association of 25(OH)D with ED and with ASCVD may be mediated by impaired glucose metabolism,” they stated.
The investigators also noted that men with ED have an increased prevalence of endothelial dysfunction, and vitamin D may improve endothelial function. “One mechanism linking low vitamin D levels with ED may be via reduced synthesis of nitric oxide,” they wrote. “Secretion of nitric oxide is needed for relaxation of the smooth muscles of the corpora cavernosa and subsequent penile erection, and vitamin D may be a regulator of endothelial nitric oxide synthase.”