Fat-soluble compounds from fermented foods and animal fats that switch on proteins placing calcium into bone and keeping it out of artery walls. Protein activation is beyond dispute; slowed bone loss in older women is well supported; artery hardening is unsettled; longer life rests on diet studies alone. Inexpensive and well tolerated, but it opposes older blood-thinning drugs. (Full Review)

Protocol

Low-dose MK-7 approach

100–200 µg daily

All-trans MK-7, once daily. 180 µg carries the strongest three-year outcome data.

High-dose MK-4 approach

45 mg daily

Menatetrenone split as 15 mg three times daily. A pharmacological, not nutritional, protocol.

Best time of day

With the largest fat-containing meal

Most often dinner. Absorption, not timing, drives the recommendation.

Time to effect

Carboxylation markers

2–4 weeks

Shift within 2–4 weeks and plateau by 8–12 weeks.

Bone density

2–3 years

Time required for change to become measurable.

Arterial stiffness

2–3 years

Time required for change to become measurable.

Benefits

High: Restoration of vitamin K–dependent protein carboxylation; slower age-related loss of bone mineral density

Medium: Reduction in clinical fracture incidence; improved arterial elasticity and slowed vascular calcification

Low: Lower cardiovascular and all-cause mortality at higher menaquinone intake; improved glycaemic control; reduced recurrence of liver cancer after curative treatment; reduced frequency of nocturnal leg cramps

Speculative: Lower incidence of advanced prostate cancer; support for brain aging and cognition

Contraindications

Vitamin K antagonist for a mechanical heart valve, unless a clinician sets a fixed dose with scheduled INR monitoring

Unstable INR (time in therapeutic range below 60%) on any vitamin K antagonist

Documented severe soy allergy, with natto-fermentation-derived MK-7

Pregnancy and breastfeeding at pharmacological MK-4 doses (above 1 mg daily)

Advanced chronic kidney disease (estimated glomerular filtration rate under 30 mL/min/1.73 m²) outside a monitored trial setting

Key Interactions

Vitamin K antagonists (warfarin, acenocoumarol, phenprocoumon): absolute caution

Direct oral anticoagulants (apixaban, rivaroxaban, dabigatran, edoxaban): no interaction

Statins (atorvastatin, rosuvastatin, simvastatin): monitor

Bile acid sequestrants (cholestyramine, colesevelam, colestipol): monitor

Orlistat (over-the-counter and prescription): monitor

Mineral oil and over-the-counter fat-blocking laxatives: caution

Broad-spectrum antibiotics (cephalosporins, rifampicin, prolonged courses): monitor

Vitamin D3 (additive effect): potentiating and generally desirable

Calcium and magnesium supplements (additive effect): potentiating

High-dose vitamin E (additive effect on clotting): caution

Nattokinase and fish oil (additive effect on clotting): caution

Risk & Side Effects

High: Antagonism of vitamin K antagonist anticoagulation

Medium: Gastrointestinal intolerance

Low: Hypersensitivity and fermentation-substrate allergen carryover; rash, itching, and headache at pharmacological MK-4 doses

Speculative: Enhanced clotting factor activity in thrombophilic individuals; breast cancer risk; sleep disturbance on long-acting MK-7

Monitoring

Marker	Target	Why
Dephosphorylated-uncarboxylated matrix Gla protein	Under 300 pmol/L	Direct readout of vascular vitamin K sufficiency
Undercarboxylated osteocalcin	Under 4.0 ng/mL, or under 20% of total osteocalcin	Direct readout of bone vitamin K sufficiency
25-hydroxyvitamin D	40–60 ng/mL	Prerequisite for the calcium absorption K2 then directs
Serum calcium (with albumin)	9.0–10.0 mg/dL	Detects the mineral dysregulation K2 is meant to correct
International normalized ratio	2.0–3.0 for those anticoagulated; not applicable otherwise	The single safety-critical measure for vitamin K antagonist users
Bone mineral density T-score (dual-energy X-ray absorptiometry)	Above −1.0; otherwise track change from personal baseline	Structural endpoint for the bone claim
Coronary artery calcium score	0 Agatston; otherwise track annualised progression against personal baseline	Structural endpoint for the vascular claim
Estimated glomerular filtration rate	Above 60 mL/min/1.73 m²	Identifies the kidney impairment that changes the risk calculus

Cadence: Vitamin K functional marker at 3 months, then every 12 months; bone density scanning every 2 years; coronary calcium scoring every 3–5 years; on a vitamin K antagonist, INR weekly for the first month after any dose change, then at the usual clinic interval.

Qualitative Assessment

Absence of new fragility fractures, height loss, or dental problems over successive years
Stable or improving exercise capacity and absence of exertional chest symptoms
Gastrointestinal tolerability — no persistent nausea, cramping, or loose stools
Subjective energy and cognitive clarity, which should be unchanged; a change points elsewhere

Vitamin K2 (MK-4 & MK-7) for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment