It appears to be increasingly apparent that Vitamin D insufficiency may have a part to play in increasing the risks for many diseases - including some NHL's.
There has been some concern in the past about whether lymphoma patients are more likely to develop hypercalcemia when supplementing with Vitamin D. I would always err on the side of caution and discuss with the oncologist/haemotologist before deciding to supplement.
Obviously they can't keep up with all of the studies so, as I intend discussing it with my own oncologist at my next appointment, I intend to bring this recent study with me, which would suggest that at the doses used there was not an issue:
ncbi.nlm.nih.gov/pmc/articl...
I thought it might be useful for anyone here who wishes to do the same.