Study design, materials and methods
Patients who applied to the Andrology Clinic with LUTS/ED between September 2017 and August 2020 and used 5 mg Tadalafil daily for treatment and did not benefit from treatment for one month were included in the study. Vitamin D levels of the patients were analyzed and Vitamin D3 100,000 IU/week oral therapy was administered for a month to the patients with low levels of Vitamin D(<20ng/ml).The values of the patients before and after Vitamin D replacement were compared.
Interpretation of results
The study results showed that Tadalafil 5 mg treatment together with Vitamin D replacement had improvement on erectile functions and LUTS in patients with Vitamin D deficiency who took Tadalafil for ED and did not respond. Moreover, it was shown that the improvement in Vitamin D levels was moderately correlated with erectile functions. The results of the present study suggest that the efficacy of Tadalafil increases with Vitamin D replacement administered by examining 25(OH) Vitamin D level in patients who do not respond to Tadalafil 5mg treatment and do no have sufficient improvement in their IIEF-EF scores. It is considered that this is caused by both the efficacy of Vitamin D replacement in the endothelial system and in increasing testosterone levels. There are similar studies in the literature; however, this is the first study, to the best of our knowledge, to evaluate the efficacy of the combined treatment after treatment ineffectiveness.