What can cause high calcium in urine (516mg), blood (10.3)?? I don't eat much calcium but take 2000iu D but my levels are in middle optimal range.

Hyperprathyroidism. Primary hyperparathyroidism should be ruled out since you have elevated serum calcium level with normal vitamin D level. Your dr can check a PTH and ionized calcium level.
Endocrinologist. An endocrinologist is best qualified to answer your question and evaluate you. 2000 units of vit D may be too much for you. An overactive parathyroid gland may be causing your elevated calcium levels.