Deficiency/Longevity/Heart

Vitamin K

Fat-soluble vitamin that supports normal clotting and may help bone and vascular health in adults with low intake.

Vitamin K

Fat-soluble vitamin that supports normal clotting and may help bone and vascular health in adults with low intake.

score

evidence

Caution

risk

Proven Benefits

01Corrects low vitamin K status

02Supports bone density

03May reduce arterial stiffness

04May reduce fracture risk

05May slow vascular calcification

06May improve insulin sensitivity

07May lower hs-CRP / IL-6

Chemical Forms

Recommended

Vitamin K2 (MK-7)
Vitamin K1 (phylloquinone)
Vitamin K2 (MK-4)

Avoid

Vitamin K3 / menadione (synthetic; potential toxicity and not for routine human supplementation)

Expert Note

K1 covers basic nutritional intake and clotting needs, while K2 as MK-7 has a longer half-life and more consistently raises extrahepatic vitamin K markers at once-daily doses. MK-4 is clinically studied but has a short half-life and is usually used in much higher split doses. Menadione is avoided because of safety concerns.

Protocol

Amount

90-180 mcg

Frequency

Once daily

When

With a meal containing fat to improve absorption.

Condition-Based Dosing

Healthy adults with low dietary vitamin K intake

90-120 mcg/day of vitamin K1 or 90-180 mcg/day of MK-7— Typical self-care range for adults not using vitamin K antagonist drugs.

Adults using vitamin D3 for bone support

90-180 mcg/day of vitamin K2 as MK-7— Common OTC range used to improve extrahepatic vitamin K status markers.

High-dose MK-4 bone protocols

45 mg/day of MK-4 split into 3 doses— Used mainly in Japanese osteoporosis studies; not a routine self-care dose.

Safety & Limits

Upper Safe Limit

No established UL for vitamin K1/K2 (NASEM/IOM); common OTC doses 90-200 mcg/day are generally well tolerated.

Cycling

Safe for continuous use

Contraindications

Warfarin, acenocoumarol, or phenprocoumon — abrupt intake changes can lower INR and reduce anticoagulant effect

Mechanical heart valve or history of unstable INR — supplement only with clinician-guided anticoagulant adjustment

Severe cholestatic liver disease or fat-malabsorption disorders — dosing and monitoring may need medical supervision

Planned surgery while on anticoagulants — keep intake stable and coordinate changes with the prescriber

Synergies

Vitamin D3

Vitamin D increases production of osteocalcin and other K-dependent proteins; vitamin K helps carboxylate them so calcium is used more effectively in bone.

Calcium

Vitamin K activates osteocalcin, which helps bind calcium into bone, so the pairing works best when calcium intake is adequate.

Avoid Combining With

✕Warfarin and similar vitamin K antagonists (directly oppose vitamin K recycling; only change intake with clinician oversight)
✕Orlistat (reduces fat absorption and lowers vitamin K uptake)
✕Bile acid sequestrants like cholestyramine (impair absorption of fat-soluble vitamins)
✕High-dose vitamin E (can oppose vitamin K-dependent clotting activity)
✕Very low-fat meals (reduce absorption; take vitamin K with food containing fat)

Updated Invalid Date