In your practice, for which D3 blood level range, do you use D3 1000, D3 2000, or D3 5000 iu supplements respectively.? Thanks in advance.

Dose based on D3 lvl. I agree with dr. Berg that serum d3 level is the most important way to properly dose vitamin d. Based on the clinical situation i shoot for levels of 55 - 80 with patients. The higher range is for those with seasonal affective disorder because higher levels of vitamin d seems to reduce the need for light therapy during the winter months and are associated with overall better mood and health.
Vit D/micronutriens. My rec, know your blood level. In some locations you don't need a doc order for blood draw, ie self order. Then, adjust the oral dose of vit d3 to achieve blood level 40 to 70. It appears some people have more serious deficiency and need more supplements. Blood level will be accurate. Rda set by government has raised the level for this vitamin. Research shows multiple health benefits levels >30.