Vit D, as a Sportsman you have to take Vit D. It has such an enormous influence on lots of different functions of our bodies.
You cannot allow yourself to be deficient on Vit D. According to my therapist very much are deficient on Vit D and I was one of them.
VIt K is important to built calcium in our bones.
I like this product because it has as well vit D as K and you can individualise the dosage.