[dchristian]

D3 is really a hormone. You are showing the classic symptoms of it becoming too high. If/when this happens, discontinue supplementing for a few days and then you can resume at a lower level. Once you understand what too high feels like, you can easily adjust.

You may need a different level in different seasons of the year (because the sunlight varies) or if you change latitude (for the same reason). Your needs may be very different to the people around you.