D3:

Development and maintenance of strong bone-tooth-muscle
Production of proteins and enzymes
Immune system shielding
Correct absorption of calcium and phosphorus

K2:

Necessary in combination with vitamin D3
Absorption of proteins and enzymes
Correct deposition and circulation of calcium
Necessary combination of D3 & K2

Vitamin D contributes to the production of proteins and enzymes that depend on K2 to activate. Lack of K2 leads to disturbing the proper functioning of their mechanism of action in the children's body.