In reply to Oma.

It can be confusing for sure. For calcium and magnesium, the concern is when they are being taken in larger amounts. If the separate calcium supplement is >200mg per dose then you would not want to take it with magnesium (or the other nutrients mentioned). The same is true for magnesium, but in doses >250mg. If doses are under those amounts, it's fine to take together.

While there may be some competition among fat soluble vitamins, at this time I don't think it's clinically significant enough to recommend separating them. There are lots of documented benefits to the synergistic nature of vitamins D and K2. However, if you are concerned and wish to take them separately, then go for it. Just be sure to take both with some healthy fat to boost absorption.