Zittermann A, et al. - In view of considering low 25-hydroxyvitamin D (25OHD) concentrations and testosterone (T) deficiency as generalized phenomenon in patients with advanced heart failure (HF), researchers investigated if vitamin D supplementation has beneficial effects on T indices in these patients. In the current work, it was noted that the decline in testosterone indices was not prevented with a daily vitamin D3 supplement of 4000 IU for 3 years in male patients with advanced HF and low 25OHD concentrations.