Intervention

Vitamin K2 (MK-7)

Last updated Sat May 30 2026 00:00:00 GMT+0000 (Coordinated Universal Time)

Observational— Rotterdam-style epidemiology; small RCTs

What it is

Vitamin K refers to a family of fat-soluble vitamins. K1 (phylloquinone) is the form in leafy greens. K2 (menaquinones, MK-n) come from animal foods and bacterial fermentation. K2 activates Gla-domain proteins:

Osteocalcin (in bone) → directs calcium into bone matrix.
Matrix Gla protein (in arteries) → inhibits arterial calcification.
Multiple other Gla-domain proteins.

Why supplementation interests longevity practitioners

Observational data (Rotterdam Study) link higher K2 intake to lower cardiovascular mortality and reduced arterial calcification.
High-dose vitamin D supplementation may raise calcium absorption; K2 helps direct it to bone rather than arteries.
The "calcium paradox" of arterial calcification with bone loss in elderly is partly attributable to insufficient K2.

Evidence ceiling

Small RCTs show reduced arterial calcification progression with MK-7.
Bone-density RCTs mixed; positive in postmenopausal women.
No large cardiovascular-outcomes RCT.

Warfarin

Vitamin K antagonises warfarin. If on warfarin, do not start vitamin K supplements without clinician input — even consistent intake can change INR target dosing.

References

Geleijnse, J. M. et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J. Nutr. 134, 3100–3105 (2004).