Yep, you nailed it. Kuinone can decrease intracellular calcium and that can lead to cramps. For some reason, when I take it with vitamin D that cramping effects disappears so if you try as well please share your experience.
That would be a good clue my chocolate milk is void of calcium or close to it which means I'll switch to regular milk again. I never had such problems from estroban but the vit k effects were less dramatic in general.