They divided 92 women with osteoporosis to 4 groups:

They divided 92 women with osteoporosis to 4 groups:
-Vitamin D3
-Vitamin K2
-Vitamin D3+k2
-Calcium Lactate

Then tested bone mineral density after 1 and 2 years.
The results?
The combination of D3+k2 won.

The combination worked best because vitamin D and K works synergistically.
Vitamin K alone came in 2nd place
Vitamin D came in 3rd
Calcium lactate was far behind.

adding vitamin E to D and K would have created even better results.