Vitamin k2 specifically as Mk4 or mk7. Mk7 has a longer half life in your system than mk4 does. Take 100 mcg per 10,000 to 15,000 of d3 you take. I use super k from lef and I take mega doses (40 to 50k) of d daily for over two years. It's definitely not something you want to skip doing. D can harm you just as Iodine without selinium like everyone has pointed out. Even if you stop the d you should take the k for a while after to be safe.