My father continually c/o fatigue/ loss of energy. Yes, he is obviously aging, but it appears to be worsening. He is 82 and a Type 2 diabetic, but otherwise, healthy and fit. His HbA1c is approximately 6.8. He was dx. years ago with prostate CA and underwent multiple radiation tx. He continues to get poor sleep due to urinary frequency. His PCP / urologist have attempted multiple meds where the side effects were more problematic than the loss of sleep. I have read that B Complex and Vit D3 may help with this. Can you please advise. With appreciation, Mary