I've recently been diagnosed with Vitamin D deficiency and my GP prescribed me some. After this I got into reading about vitamins, supplements, etc. and I came across the fact that if one takes Vitamin D, they should also take Vitamin K.

So I went on to read and look for Vitamin K, which is K2. And then I read that it also branches into MK-4 and MK-7. Some people say MK-7 could be harmful, some say it's a must.

I'm confused. Should I take Vitamin K with D and also which? Also any brands that are known to be goo quality or are the H&B ones just fine?

For context, I live in UK and work only the night shift, so I never get sunlight.

Also any other suggestions or advices on other supplements/vitamins and quality brands, or any advice at all is welcome, thank you!