What are Calcium + Vitamin D3 + Vitamin K1 Capsules? Not the snappiest name, we know, but as with all our Pure Series™ products – we say it how it is! BULK POWDERS™ have combined 3 of the most popular bone health nutrients into one convenient capsule! Each ingredient has been included in not only its most effective format, but also at its most effective dose. For example, the Calcium inclusion is highly bioavailable Calcium Citrate (as opposed to other less bioavailable formats