Benefits
Bone strength
In a 3-year randomized trial in 244 healthy postmenopausal women, 180 mcg/day of MK-7 improved vitamin K status and decreased the age-related decline in bone mineral content and bone mineral density at the lumbar spine and femoral neck compared with placebo (Knapen 2013). This is the best-supported use of MK-7 and the evidence is specific to bone.
Matrix Gla protein activation in vessel walls
Vitamin K2 is a cofactor for the carboxylation (activation) of matrix Gla protein, which in laboratory and animal work binds calcium in vessel walls. In people, a 3-year placebo-controlled trial found MK-7 cut the inactive form of matrix Gla protein by 50% versus placebo, alongside lower arterial stiffness markers (see the arterial stiffness benefit), but no trial cited on this page measured vascular calcification itself or heart events.
Calcium routing
MK-7 supports the carboxylation of vitamin-K-dependent proteins involved in calcium handling, including osteocalcin in bone, and is commonly paired with calcium and vitamin D. The broader idea that MK-7 "routes" dietary calcium into bone and away from soft tissue is a mechanistic hypothesis rather than an outcome measured in the trials cited here.
Arterial stiffness markers studied in postmenopausal women
A 3 year placebo controlled trial in 244 healthy postmenopausal women gave 180 mcg a day of MK-7 as another brand (MenaQ7); VitaMK7 itself was not tested. Two arterial stiffness measures, carotid-femoral pulse wave velocity and stiffness index beta, fell significantly, and inactive matrix Gla protein dropped 50% versus placebo. Inflammation and endothelial markers did not change. One trial, markers only, not heart events.
Mechanism of action
Osteocalcin activation
MK-7 carboxylates (activates) osteocalcin, the protein that binds calcium into the bone matrix, strengthening bone.
Matrix Gla protein activation
MK-7 carboxylates (activates) matrix Gla protein, which in laboratory and animal work inhibits calcium deposition in artery walls. In people, a 3-year trial cited on this page found lower inactive matrix Gla protein and lower arterial stiffness markers with MK-7, but no trial cited here measured arterial calcification or cardiovascular events.
Clinical trials
Three-year randomized, placebo-controlled trial of 180 mcg/day menaquinone-7 (MK-7) in 244 healthy postmenopausal women. (Knapen et al. 2013, Osteoporosis International). Endpoints were vitamin K status and bone density; the trial tested MK-7 as a nutrient form, and no trial of the VitaMK7® brand itself is cited on this page.
Healthy postmenopausal women.
MK-7 at 180 mcg/day for 3 years significantly improved vitamin K status and decreased the age-related decline in bone mineral content and bone mineral density at the lumbar spine and femoral neck versus placebo. Bone and vitamin K status were the endpoints measured; this bone report did not cover arterial stiffness (reported separately and described in the benefits), vascular calcification, or cardiovascular events.