Hi. Not likely at all to be cancer. With the low vitamin D levels your calcium can be elevated and actually 10.4 isn't all that high. The only other possibility here--not at all likely--would be a parathyroid adenoma which is benign, not cancer
Let me know if you need more information here
I would respectfully ***** *****
low vitamin d levels itself do not cause high calcium levels.
however overactive parathyroid gland ( due to primary hyperparathyroidism or adenoma or for any other reason ) can cause high calcium levels and can deplete vitamin d levels.
I recommend testing for repeat calcium levels, phosphate levels, alkaline phosphatase levels to further pinpoint the source of high calcium. i would also like to review your medication list , as a number of medications can cause high calcium levels.
I would agree on the part that high calcium due to cancer is highly unlikely in this case as in that case calcium level is very high (usually above 14).