Hermetica Superfood Encyclopedia
The Short Answer
MK-4 is a short-chain menaquinone whose primary bioactive mechanism involves serving as a cofactor for gamma-glutamyl carboxylase, enabling gamma-carboxylation of vitamin K-dependent proteins such as osteocalcin and matrix Gla protein, and is also biosynthesized in tissues via UBIAD1-mediated geranylgeranylation of menadiol. At pharmacological oral doses of 1500 µg/day, MK-4 improves osteocalcin carboxylation, though single doses up to 420 µg and 7-day regimens of 60 µg/day fail to produce detectable serum increases in healthy women, underscoring its unique tissue-targeted rather than serum-mediated pharmacokinetics.
CategoryVitamin
GroupMineral
Evidence LevelPreliminary
Primary KeywordMK-4 vitamin K2 benefits
MK-4 — botanical close-up
Health Benefits
**Bone Protein Carboxylation**
MK-4 activates osteocalcin via gamma-carboxylation, enabling calcium binding in bone matrix; doses of 1500 µg/day are required to measurably improve carboxylation status, as confirmed in dose-finding trials by Takeuchi et al.
**Tissue-Specific Accumulation**
Unlike MK-7, MK-4 accumulates directly in testes, pancreas, arterial walls, and nervous tissue through local UBIAD1-mediated biosynthesis, suggesting organ-protective roles independent of circulating serum levels.
**Vascular Calcification Inhibition**
Through carboxylation of matrix Gla protein (MGP) in arterial walls, MK-4 may inhibit pathological calcium deposition in vascular smooth muscle; this mechanism is shared with other K2 forms but MK-4's local tissue synthesis positions it uniquely at arterial sites.
**Antioxidant Activity**
The naphthoquinone ring structure of MK-4 confers intrinsic antioxidant capacity, allowing it to scavenge reactive oxygen species and potentially protect cell membranes in tissues where it accumulates at high concentrations.
**Osteoporosis Management (Pharmacological Use)**
Menatetrenone (MK-4) is approved in Japan at doses of 45 mg/day (45,000 µg/day) for osteoporosis treatment, with clinical evidence supporting reductions in vertebral fracture risk in postmenopausal women at these pharmacological doses.
**Coagulation Cascade Support**
As a functional vitamin K2 form, MK-4 supports hepatic gamma-carboxylation of clotting factors II, VII, IX, and X, though longer-chain MKs such as MK-7 demonstrate greater potency for extrahepatic coagulation factor support at nutritional doses.
**Neuroprotective Potential**
MK-4 is the predominant K2 vitamer in brain tissue and is hypothesized to support sphingolipid synthesis and myelination, with preclinical evidence suggesting roles in neurological function, though human clinical data remain limited.
Origin & History
Natural habitat
MK-4 (menatetrenone) is not obtained directly from a single geographic source but is biosynthesized in animal tissues worldwide through enzymatic conversion of dietary phylloquinone (vitamin K1). It accumulates preferentially in specific tissues including the testes, pancreas, arterial walls, and brain of vertebrates, rather than circulating abundantly in serum. Dietary sources include animal-derived foods such as meat, liver, eggs, and dairy products, with no significant bacterial fermentation pathway unlike longer-chain menaquinones such as MK-7.
“MK-4 has no documented history of use in traditional medicine systems such as Ayurveda, Traditional Chinese Medicine, or European herbalism, as the compound was not identified or isolated until the mid-twentieth century. The vitamin K family was first described by Henrik Dam in 1929 in relation to a hemorrhagic disease in chickens, with the structural distinction between K1 and K2 forms established through subsequent biochemical research in the 1940s–1960s. MK-4's clinical identity as menatetrenone emerged from Japanese pharmaceutical research, where it was developed and approved as an osteoporosis treatment, reflecting Japan's long-standing integration of micronutrient-based therapies into mainstream clinical practice. Unlike MK-7, which has a cultural association with the traditional Japanese fermented food natto, MK-4 has no analogous food-cultural heritage and is regarded primarily as a pharmaceutical or synthetic nutritional compound.”Traditional Medicine
Scientific Research
The clinical evidence base for MK-4 at nutritional supplemental doses is limited, consisting primarily of small pharmacokinetic studies and dose-finding trials without published effect sizes (Cohen's d) or formal power calculations. Key pharmacokinetic studies in healthy Japanese females demonstrate that single oral doses of 420 µg and 7-day consecutive doses of 60 µg/day produce undetectable serum MK-4 (0.00 ± 0.77 ng/mL), contrasting sharply with MK-7's robust 48-hour serum persistence, while a comparative absorption study using 900 µg showed MK-4 had both a shorter serum half-life and smaller area under the curve than vitamin K1 or MK-9. Dose-finding work by Takeuchi et al. in healthy subjects established that 500 µg/day for two months had no measurable effect on osteocalcin carboxylation, whereas 1500 µg/day produced improvement, providing a functional threshold but without large-scale RCT replication. The strongest clinical evidence for MK-4 exists at pharmacological doses (45 mg/day as menatetrenone) used in Japanese osteoporosis trials, where RCTs have demonstrated fracture risk reduction, but these findings are not directly applicable to typical dietary supplement dosing contexts in Western markets.
Preparation & Dosage
Traditional preparation
**Oral Capsule/Tablet (Nutritional Supplement)**
5 mg/day) represent the minimum threshold for measurable improvement in osteocalcin carboxylation based on clinical dose-finding data; doses of 60–500 µg/day have not demonstrated serum detectability or functional biomarker changes
Doses of 1500 µg/day (1..
**Pharmaceutical Menatetrenone (Japan)**
45 mg/day (45,000 µg/day) in three divided doses of 15 mg for osteoporosis treatment; this is a prescription pharmacological dose and is not representative of nutritional supplementation
Approved at .
**Soft-Gel Formulation with Fat**
MK-4 is a fat-soluble compound and should be administered with a fat-containing meal to optimize intestinal absorption; co-ingestion with dietary fat enhances micellar solubilization and lymphatic transport.
**Synthetic Supplement Form**
Menatetrenone USP reference standard is produced synthetically from menadione via geranylgeranylation; supplement-grade MK-4 is typically derived from the same synthetic route rather than fermentation.
**Dosing Frequency**
Due to its short serum half-life relative to MK-7, MK-4 at pharmacological doses is administered in divided doses (e.g., three times daily) to maintain tissue exposure; single daily dosing may be insufficient at lower supplemental ranges.
**Standardization**
No internationally recognized standardization percentage applies; purity is defined by USP or equivalent pharmacopoeial monographs specifying ≥97% menatetrenone content by HPLC.
Nutritional Profile
MK-4 is a pure lipophilic micronutrient compound with the molecular formula C31H40O2 and molecular weight of 444.65 g/mol; it contributes no caloric macronutrients, protein, carbohydrate, or fiber. Dietary concentrations in animal foods are low and variable: liver and certain organ meats contain the highest tissue concentrations, while muscle meat, eggs, and dairy provide smaller amounts; precise food-level concentrations are not consistently tabulated in standard nutrient databases due to analytical challenges. Bioavailability is highly context-dependent: intestinal absorption requires bile acids and dietary fat for micellar incorporation, and once absorbed via the lymphatic system, MK-4 is rapidly cleared from serum and partitioned into peripheral tissues. The compound's partition into tissues such as testes, pancreas, and brain means that serum levels are a poor proxy for tissue status, complicating nutritional assessment and supplementation monitoring.
How It Works
Mechanism of Action
MK-4 functions as an essential cofactor for the enzyme gamma-glutamyl carboxylase (GGCX), facilitating post-translational gamma-carboxylation of glutamic acid residues on vitamin K-dependent proteins (VKDPs) including osteocalcin, matrix Gla protein, and coagulation factors; during this reaction, MK-4 is oxidized to its epoxide form and must be recycled by vitamin K epoxide reductase (VKORC1) to maintain the active hydroquinone pool. Endogenous biosynthesis of MK-4 proceeds through a three-step enzymatic pathway: phylloquinone's phytyl tail is cleaved by an unidentified enzyme to yield menadione (vitamin K3), menadione is reduced to menadiol by NAD(P)H:quinone oxidoreductase 1 (NQO1), and menadiol is then geranylgeranylated by the prenyltransferase UBIAD1 using geranylgeranyl pyrophosphate (GGPP) as the prenyl donor, producing menaquinol-4. Beyond carboxylation, MK-4 has been identified as a ligand for the steroid and xenobiotic receptor (SXR/PXR), through which it may regulate transcription of genes involved in bone metabolism and cell survival. The short four-isoprene side chain renders MK-4 highly hydrophobic and facilitates rapid cellular uptake into tissues but simultaneously limits its incorporation into lipoprotein particles, explaining its negligible serum presence after physiological or low pharmacological oral doses.
Clinical Evidence
The most rigorous clinical data for MK-4 derive from its use as the pharmaceutical agent menatetrenone at 45 mg/day (45,000 µg/day) for postmenopausal osteoporosis in Japan, where randomized controlled trials have reported reductions in vertebral fracture incidence, though many of these trials were conducted in Japan with specific dietary backgrounds and have not been uniformly replicated in Western cohorts. At nutritional supplemental doses (60–500 µg/day), clinical trials consistently fail to demonstrate measurable increases in serum MK-4 or improvements in carboxylated osteocalcin, establishing a clear dose-response threshold around 1500 µg/day for any detectable biochemical effect. Comparative pharmacokinetic studies confirm MK-4's inferiority to MK-7 for serum bioavailability and sustained carboxylation support at equivalent microgram doses, suggesting that for circulating biomarker endpoints, MK-7 is the preferred supplemental K2 form. Confidence in MK-4's benefits at supplemental doses below 1500 µg/day is low; confidence in the pharmacological 45 mg/day dose for bone endpoints is moderate, constrained by population-specific trial designs and limited independent replication.
Safety & Interactions
At supplemental doses up to 1500 µg/day and in pharmacokinetic trials up to 900 µg single doses, no adverse events have been reported in published studies; the pharmacological menatetrenone dose of 45 mg/day has been used in clinical trials without significant safety signals, though comprehensive long-term safety data at this dose are not as extensive as for many pharmaceutical agents. As a vitamin K2 form, MK-4 carries the class-wide interaction risk with vitamin K antagonist anticoagulants (e.g., warfarin, acenocoumarol): concurrent use can reduce anticoagulant efficacy by competing at the VKORC1 enzyme, and patients on these medications should consult a physician before using any vitamin K supplement. No specific teratogenicity data exist for MK-4 supplementation in pregnancy; general vitamin K guidelines suggest that physiological doses are unlikely to pose risk, but pharmacological doses during pregnancy have not been adequately studied and should be avoided without medical supervision. Individuals with rare hereditary conditions affecting vitamin K metabolism or those taking orlistat or cholestyramine (which impair fat-soluble vitamin absorption) may have altered MK-4 absorption and require monitoring.
Synergy Stack
Hermetica Formulation Heuristic
Also Known As
Menaquinone-4MenatetrenoneVitamin K2 MK-4MK4Phytonadione metabolite (tissue form)
Frequently Asked Questions
What is the difference between MK-4 and MK-7?
MK-4 and MK-7 are both vitamin K2 forms but differ critically in their side chain length, origin, and pharmacokinetics: MK-4 has four isoprene units, is synthesized in animal tissues from vitamin K1 via UBIAD1, and is rapidly cleared from serum with near-zero detectability after nutritional doses. MK-7 has seven isoprene units, is produced by bacteria (notably in natto fermentation), has a serum half-life of approximately 72 hours, and achieves sustained circulating levels that support extrahepatic carboxylation of osteocalcin and matrix Gla protein more effectively at microgram doses. For circulating biomarker endpoints, MK-7 is generally superior at equivalent doses, while MK-4's significance lies in its direct tissue accumulation and its pharmacological use at 45 mg/day for osteoporosis in Japan.
What dose of MK-4 is needed to improve bone health?
Dose-finding research by Takeuchi et al. established that 500 µg/day of MK-4 for two months had no detectable effect on osteocalcin carboxylation in healthy subjects, while 1500 µg/day produced measurable improvement, identifying this as the minimum effective supplemental threshold. At the pharmacological level, the Japanese-approved menatetrenone dose for osteoporosis treatment is 45 mg/day (45,000 µg/day) divided into three daily doses, which is approximately 30-fold higher than the 1500 µg threshold and is used under medical supervision. Typical Western vitamin K2 supplements providing 60–200 µg MK-4 are unlikely to produce bone-specific biochemical effects based on available pharmacokinetic evidence.
Why is MK-4 not detectable in blood after supplementation?
MK-4's near-zero serum detectability after oral supplementation at nutritional doses (60–420 µg) is due to its short serum half-life and rapid partitioning into peripheral tissues rather than reflecting poor intestinal absorption. Its highly hydrophobic short chain allows rapid cellular uptake by tissues such as the testes, pancreas, brain, and arterial walls, where UBIAD1 enzyme activity also contributes to local biosynthesis, effectively depleting the circulating pool. This tissue-first pharmacokinetic behavior means serum MK-4 levels are a poor biomarker of total body K2 status, and studies in healthy Japanese women consistently report 0.00 ng/mL serum MK-4 even after 7 days of 60 µg/day dosing.
Is MK-4 safe to take with warfarin or other blood thinners?
MK-4, like all vitamin K forms, can antagonize the anticoagulant effect of warfarin and other vitamin K antagonists (e.g., acenocoumarol, phenprocoumon) by competing at the vitamin K epoxide reductase complex (VKORC1), the enzyme warfarin inhibits to prevent clotting factor carboxylation. Even at supplemental doses, any increase in vitamin K activity can destabilize a patient's INR (international normalized ratio), potentially reducing anticoagulant protection and increasing thrombotic risk. Patients on anticoagulation therapy should not initiate MK-4 supplementation without physician guidance and INR monitoring, and any consistent dietary vitamin K2 intake should ideally be held constant to maintain stable anticoagulant dosing.
What foods contain the most MK-4 naturally?
MK-4 is found predominantly in animal-derived foods because it is biosynthesized in vertebrate tissues from dietary phylloquinone (vitamin K1) rather than being produced by bacteria or obtained directly from plants. The richest dietary sources include organ meats (particularly liver and brain), egg yolks, butter, and full-fat dairy products, where MK-4 accumulates as a result of the tissue conversion process. Fermented foods like natto, which is the primary dietary source of MK-7, contain minimal MK-4, and plant foods do not provide meaningful amounts; therefore, vegans and individuals avoiding animal products are most likely to have reduced dietary MK-4 intake.
How does MK-4 accumulate differently in tissues compared to other vitamin K forms?
MK-4 is unique in its ability to directly accumulate in specific tissues including the testes, pancreas, arterial walls, and nervous tissue, rather than remaining primarily in the liver like other vitamin K forms. This tissue-specific distribution suggests MK-4 plays specialized roles in reproductive health, metabolic function, and vascular and neurological protection. The mechanism underlying this preferential accumulation remains an active area of research.
What dose of MK-4 is required to activate bone proteins like osteocalcin?
Clinical dose-finding trials, including research by Takeuchi et al., have demonstrated that approximately 1500 µg (1.5 mg) per day of MK-4 is necessary to achieve measurable improvements in gamma-carboxylation of osteocalcin. This carboxylation is essential for enabling calcium binding within the bone matrix and supporting bone mineralization. Doses below this threshold typically do not produce statistically significant changes in bone protein carboxylation status.
Why might someone choose MK-4 over MK-7 for cardiovascular and neurological support?
MK-4 accumulates selectively in arterial walls and nervous tissue at higher concentrations than MK-7, making it potentially better suited for supporting vascular and neurological health specifically. While MK-7 remains longer in circulation and is better absorbed from dietary sources, MK-4's tissue-specific distribution may provide targeted benefits for cardiovascular and central nervous system function. The choice between these forms depends on whether you prioritize systemic circulation (MK-7) or direct accumulation in these specialized tissues (MK-4).
Explore the Full Encyclopedia
7,400+ ingredients researched, verified, and formulated for optimal synergy.
Browse IngredientsThese statements have not been evaluated by the Food and Drug Administration. This content is for informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease.
hermetica-encyclopedia-canary-zzqv9k4w mk-4-menaquinone-4 curated by Hermetica Superfoods at ingredients.hermeticasuperfoods.com and licensed CC BY-NC-SA 4.0 (non-commercial share-alike, attribution required)
