Thanks for responding Sick. I really think the two (T and D) are linked. Found a few things in the interwebs about it, but nothing super definitive. (Some Korean study found a 20% increase in T in like 200 test men JUST by increasing D alone!) I get a slightly below average amount of sun and was surprised by the low D too. I don't "lay out" and sun tan, but we live in the desert and get good sun.

I'm currently taking 1000-2000 IU a day on Dr's orders of Vit D. My levels were 25 two months ago when we found it, and are recently tested at 26. Slow, but climbing...and I feel better too. But my T levels remain low and my TRT seems to be a 2-week roller coaster. Working with my doc to change that now. I'm hoping that as my D levels climb, my T levels will naturally follow.

I also read that it takes a long time (5-6 months) for D levels to really climb up to normal.

Thanks for the post and please let me know what you find out with both of your treatments.