Vitamin K2 (MK-7)
Long-half-life menaquinone supporting bone matrix and arterial elasticity, RCT signal at 180 µg/day over 3 years.
Why
Vitamin K2 menaquinone-7 (MK-7) carries an EFSA-authorised health claim for normal bone maintenance. The Rotterdam Heart Study reported lower coronary calcification with higher K2 intake. The three-year Knapen RCT in postmenopausal women showed reduced vertebral fracture risk and preserved bone mineral density at 180 µg/day, plus reduced arterial stiffness, the latter unique to K2 among bone supplements.
How it works
Cofactor for γ-carboxylation of vitamin K-dependent proteins: osteocalcin (binds calcium into bone hydroxyapatite) and matrix Gla protein (prevents calcium deposition in arterial walls). MK-7 has a half-life of ~72 hours, substantially longer than K1, supporting once-daily dosing.
Expected onset · Bone and arterial endpoints assessed over 12–36 months; biochemical changes (carboxylated osteocalcin) within weeks
How to take
Dosage
MK-7: 90–180 µg/day with a meal containing fat. Often paired with vitamin D3.
Timing
With the largest meal of the day
On the label
MK-7 (menaquinone-7), all-trans form, with stated micrograms. Avoid MK-4 alone if you want the long-half-life form, MK-4's half-life is much shorter.
Ideal for
Adults at risk of osteoporosis or with elevated coronary calcium scores; postmenopausal women; people on long-term vitamin D supplementation.
Safety
Evidence
EFSA authorised the claim that vitamin K contributes to the maintenance of normal bones. Knapen 2013 Osteoporos Int three-year RCT (n=244): MK-7 180 µg/day preserved vertebral height, lowered fracture risk and improved hip bone mineral content vs placebo. Knapen 2015 Thromb Haemost RCT: same dose reduced carotid-femoral pulse wave velocity (arterial stiffness) at 3 years.
- EFSA Reg 432/2012 authorised claim, 'Vitamin K contributes to the maintenance of normal bones'
- Knapen et al., Osteoporos Int 2013, three-year MK-7 RCT in postmenopausal women (n=244)
- Knapen et al., Thromb Haemost 2015, MK-7 supplementation improves arterial stiffness in healthy postmenopausal women (RCT)
Where to get it
Shop Vitamin K2 (MK-7) on AmazonSponsored · As an Amazon Associate, Healicus earns from qualifying purchases.