Vitamin D and Male Erectile Function: An Updated Review

Mechanisms Suggesting a Relationship between Vitamin D and Erectile Dysfunction: An Overview

Vitamin D deficiency (VDD) and erectile dysfunction (ED) heavily burden the male population. The higher prevalence of both conditions in the elderly suggests a possible relationship between the two conditions. In addition, in vitro, animal, and human studies have revealed several mechanisms that may relate VDD to ED. The main mechanism by which vitamin D might exert its action on sexual function appears to be through the regulation of endothelial function. Indeed, VDD correlates with several markers of endothelial function. The action of vitamin D on the endothelium would be exercised both indirectly through its intervention in inflammatory processes and through the production of oxygen free radicals, and directly through the regulation of vascular stiffness, the production of nitric oxide, and the regulation of vessel permeability. Furthermore, the ubiquitous distribution of the vitamin D receptor in the human body means that this hormone can also exert a beneficial effect on erectile function by interfering with those comorbidities significantly associated with ED, such as hypertension, diabetes mellitus, hypercholesterolemia, chronic kidney disease, and hypogonadism. In this review, we thoroughly and carefully presented the evidence and mechanisms that would appear to relate vitamin D levels to erectile function. Furthermore, we have summarized the meta-analytic evidence for and against this association to provide a true representation of this topic. Data published to date suggest that low levels of vitamin D could contribute to worsening erectile function through several mechanisms. Therefore, vitamin D levels should be measured in patients with ED and maintained at adequate levels by specific supplementation in case of deficiency. However, the low quality and heterogeneity of clinical trials evaluating the effects of vitamin D administration on erectile function and ED-associated comorbidities do not allow for a univocal conclusion, and indicate the need for further studies to analyze these aspects.

Whether Adding Vitamin D to Tadalafil 5 mg Treatment Is Useful in Patients with Erectile Dysfunction and Vitamin D Deficiency?

INTRODUCTION

Numerous factors such as endothelial disease and hormonal disorder cause the development of erectile dysfunction (ED). However, the relationship between vitamin D deficiency (VDD) and ED is unclear. Moreover, the benefit of vitamin D replacement on ED patients with VDD is uncertain. As far as we know, there is no study yet in the literature regarding the addition of vitamin D to phosphodiesterase type 5 inhibitors in the treatment of ED patients with VDD. In this study, we investigated whether adding vitamin D to daily tadalafil treatment would be beneficial in ED patients with VDD.

METHODS

A total of 111 patients with VDD accompanying ED were retrospectively evaluated between January 2016 and December 2019. Patients were divided into 2 groups according to the treatment they received. Group 1 (n = 58) was treated with daily oral tadalafil 5 mg, while group 2 (n = 53) received oral tadalafil 5 mg and 4,000 IU vitamin D3. Total International Index of Erectile Function-15 (IIEF-15) scores and vitamin D levels of the groups were compared at the end of the study.

RESULTS

The mean vitamin D level was increased statistically significant in group 2, but no difference was seen in group 1 (p < 0.001 and p > 0.05, respectively). There was a significant increase in median erectile function, orgasmic function, sexual desire, sexual satisfaction, and overall satisfaction scores in both groups (p < 0.001). However, the increase in median erectile function and sexual desire scores was significantly higher in group 2 compared to group 1 at the end of the study (p = 0.01 and p < 0.001, respectively).

CONCLUSION

We found that adding vitamin D to 5 mg oral daily tadalafil treatment may have an additional positive effect on erectile function and sexual desire in ED patients with VDD.

Low Serum 25-Hydroxyvitamin D Level as a Potential Risk Factor of Erectile Dysfunction in Elderly Men with Moderate to Severe Lower Urinary Tract Symptoms

Purpose

To evaluate the correlation between vitamin D level and erectile dysfunction (ED) in male lower urinary tract symptoms (LUTS) patients.

Materials and Methods

We analyzed data from 534 male patients who were tested for LUTS from 2014 to 2017. LUTS severity was classified into mild (≤7) or moderate to severe (≥8) based on total IPSS scores. Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D [25(OH)D] level of less than 20 ng/mL. The severity of ED was dichotomized into mild (≥17 points) or moderate to severe (≤16 points) depending on total IIEF-5 scores. The association of the serum 25(OH)D level with moderate to severe ED was assessed using logistic regression analysis.

Results

In the entire cohort, moderate to severe ED was significantly associated with age ≥60 years (odds ratio [OR], 1.762; 95% confidence interval [CI], 1.011–3.073) and moderate to severe LUTS (OR, 2.075; 95% CI, 1.134–3.789), but not with serum 25(OH)D level (OR, 1.001; 95% CI, 0.979–1.023). Whereas, in the subgroup consisting of moderate to severe LUTS patients over 60 years (n=223), either low serum 25(OH)D level (OR, 0.944; 95% CI, 0.903–0.986) or vitamin D deficiency (OR, 2.949; 95% CI, 1.118–7.782) was the independent risk factor of moderate to severe ED as a result of each multivariate analysis.

Conclusions

Low vitamin D status closely correlated with moderate to severe ED in elderly men with moderate to severe LUTS.

Is There an Association Between Vitamin D Deficiency and Erectile Dysfunction? A Systematic Review and Meta-Analysis

Erectile dysfunction (ED) is found very frequently in the male population, in particular in its arteriogenic form, which also represents an important predictor of cardiovascular diseases (CVDs). Some evidence suggests that vitamin D could play a role in cardiovascular risk prevention thanks to its ability to reduce endothelial damage, oxidative stress, the production of inflammatory cytokines, and dyslipidemia. Since ED and CVDs have pathogenic mechanisms in common, numerous studies have evaluated a possible association between vitamin D deficiency (blood concentrations of 25-hydroxyvitamin D < 20 ng/mL) and ED, but with conflicting results. This meta-analysis was therefore performed to clarify the discrepancy of the data so far published. To achieve this, articles have been searched extensively in the Pubmed, MEDLINE, Cochrane, Academic One Files, Google Scholar, and Scopus databases from the first day they were created until January 2020. The search strategy included pertinent Medical Subjects Headings (MeSH) terms. Of the 431 items retrieved, only eight observational studies were included, resulting in a total sample size of 4055 patients. It was found that 25-hydroxyvitaminD (25(OH)D) levels did not show any significant difference between patients with and without ED. However, when patients with vitamin D deficiency only were taken into account, the international index of erectile function (IIEF) score for erectile dysfunction was significantly worse than in controls. This association remained significant even when eugonadal-only patients were considered. Finally, we found that eugonadal patients with severe ED have lower 25(OH)D₃ levels than patients with mild ED. In conclusion, this meta-analysis suggests an association between vitamin D deficiency and the presence of severe forms of ED, independent of testicular function.