D3 by itself can cause high calcium levels, to the point of toxicity in very high doses. The K2 moves the calcium from the blood to bones.
I developed a calcification in my arm due to this. My wrist was in pain and I couldn't bend it. Got an x-ray, and boom: what looked like a little ball of bone had appeared.
Stopped taking D3 immediately and my body reabsorbed it, never had it again.
Funny enough, it happened when I was visiting Paris. Got to use Google Translate to explore the French medical system. Fantastic service, people aren't joking! :)
Not sure how much D3 you're getting (though starting with 3K IU is a lot) because it's not clear how much gets through the gut. You might want to take some cod liver oil (Ω3 capsules) at the same time -- the fat is believed to improve the still mysterious absorption process.
Typical dosage is a drop of cholecalciferol suspension under the tongue for direct absorption.
Possibly good for prostate health as well. Another reason to try I forgot to mention.