Vitamin K2 (MK-7) is a type of vitamin K2, which contains seven isoprene units in the side chain of vitamin K2. It is a fat soluble vitamin and one of the indispensable important vitamins in human body.
Vitamin K2 (MK-7): used for osteoporosis, improvement of arterial calcification and treatment of Parkinson's disease
Vitamin K2 (MK-4): for osteoporosis
Therefore, vitamin K2 (MK-7) is far superior to vitamin K2 (MK-4) in terms of biological activity, bioavailability and efficacy.