You might try this:
Take 600mg Magnesium salt (magnesium citrate, chelate or other) plus 1mg-1.5mg vitamin K2 mixed (menaquinone 7 and menaquinone 4) for three to four weeks before any supplementation with vitamin D3. If possible have your serum calcium levels rechecked to see if they have lowered.
At any rate taking the vitamin D3 along with the magnesium plus K2 should avoid any rise in serum calcium. Of course it is best to have the levels rechecked.