Vitamin K2
Vitamin K2
Snapshot
VitaminโฏK2 is a fatโsoluble vitamin crucial for activating proteins that regulate calcium metabolism, supporting bone mineralization, vascular health, and proper blood clotting.
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What is Vitamin K2 (Menaquinone)?
VitaminโฏK2 refers to the menaquinone family of compounds (MKโ4 through MKโ13), distinguished by varying isoprenoid sideโchain lengths. Unlike vitaminโฏK1 (phylloquinone), K2 forms are produced by gut bacteria and found in fermented foods, with superior tissue distribution.
Where It Comes From
Dietary vitaminโฏK2 is sourced from fermented foods such as natto (rich in MKโ7), aged cheeses, and animal products like liver and egg yolks (notably MKโ4). Supplements provide synthetic or fermentationโderived MKโ4 or MKโ7 forms in oilโbased capsules.
Key Nutrients & Compounds
Provides menaquinones (MKโ4 commonly at 1โ5โฏmg doses, MKโ7 at 100โ200โฏยตg) that serve as cofactors for ฮณโglutamyl carboxylase, converting osteocalcin and matrix Gla protein into their active, calciumโbinding forms.
Health Benefits
VitaminโฏK2 activates osteocalcin, facilitating calcium incorporation into bone matrix and enhancing bone strength; activates matrix Gla protein, inhibiting arterial calcification and supporting cardiovascular health; and contributes to normal coagulation via activation of clotting factors II, VII, IX, and X.
Recommended Dosage
No official RDA exists for K2 specifically. Clinical studies use 45โ180โฏยตg/day of MKโ7 or 1โ5โฏmg/day of MKโ4. A common supplemental regimen is 100โฏยตg of MKโ7 daily alongside vitaminโฏD to synergize calcium metabolism.
How to Use It
Take VitaminโฏK2 (MKโ7 or MKโ4) supplements with a meal containing dietary fat to optimize absorption. For combined bone support, pair with vitaminโฏD3 and calcium. Maintain consistent daily dosing to sustain active Glaโprotein levels.
Who Should Use It?
Individuals at risk for osteoporosis, those with low dietary vitaminโฏK intake, postmenopausal women, and anyone seeking to support healthy calcium balance and vascular integrity may benefit. Consult a healthcare provider if on anticoagulant therapy.
Possible Interactions or Cautions
VitaminโฏK2 may reduce the effectiveness of vitaminโฏKโantagonist anticoagulants (e.g., warfarin); monitor INR and adjust medication under medical supervision. High doses are generally well tolerated, with no known toxicity.
Final Thoughts
VitaminโฏK2 is a key modulator of calcium utilization, directing it toward bone and away from arteries. When combined with vitaminโฏD and calcium, it offers synergistic support for skeletal and cardiovascular health in a balanced supplementation strategy.
Scientific Studies
KnapenโฏMHJ, etโฏal. Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women: a double-blind randomised clinical trial. Thromb Haemost. 2015;113(5):1135โ1144. https://doi.org/10.1160/TH14-11-0938
IkedaโฏY, etโฏal. Effect of oral administration of vitamin K2 (menatetrenone) on bone metabolism and bone mass in osteoporosis. Bone. 1997;20(5):431โ436. https://doi.org/10.1016/S8756-3282(97)00041-0
SchurgersโฏLJ, VermeerโฏC. Differential lipoprotein transport pathways of K-vitamers in healthy subjects. Biochim Biophys Acta. 2002;1570(1):27โ32. https://doi.org/10.1016/S0005-2760(02)00112-1