Vitamin K2 MK-7 (Menaquinone-7, CAS 2124-57-4) is a fermentation-derived menaquinone produced by Bacillus subtilis natto — the same bacterium responsible for traditional Japanese natto. MK-7 functions as an essential cofactor for γ-glutamyl carboxylase (GGCX), the enzyme that activates vitamin K-dependent proteins (VKDPs) through post-translational γ-carboxylation of glutamic acid residues to γ-carboxyglutamate (Gla), enabling calcium-binding capacity. The two clinically most significant VKDPs are osteocalcin (secreted by osteoblasts; activated osteocalcin binds calcium and transports it into bone matrix for hydroxyapatite mineralization, directly supporting bone mineral density and fracture resistance) and Matrix Gla Protein (MGP) (expressed in vascular smooth muscle cells; the most potent endogenous inhibitor of arterial calcification — activated MGP scavenges free calcium from arterial walls, preventing medial calcium-phosphate deposition and preserving arterial elasticity). Without adequate MK-7, both proteins remain in their inactive undercarboxylated forms (ucOC and ucMGP), contributing to the ‘calcium paradox’ — simultaneous bone mineral loss and arterial stiffening. MK-7’s long 7-unit isoprenoid side chain enables preferential incorporation into LDL/VLDL lipoproteins for systemic extrahepatic distribution, while its ~72-hour half-life ensures sustained 24-hour VKDP carboxylation at microgram (not milligram) doses. UPOR Biotech provides MK-7 at ≥99% all-trans isomer purity — only the all-trans configuration is biologically active; cis isomers are inactive.

MK-7 provides four decisive advantages over MK-4 and Vitamin K1: (1) Half-life superiority — MK-7 has a ~72-hour plasma half-life, approximately 3× longer than K1 (~24 hours), 48× longer than MK-4 (~1.5 hours), and nearly 100× longer than dietary phylloquinone from leafy greens (~1 hour). This enables once-daily dosing with stable 24-hour VKDP carboxylation. (2) Extrahepatic tissue distribution — MK-7’s 7-unit side chain enables preferential LDL/VLDL-mediated transport to bone, arteries, and soft tissues; K1 is largely retained in the liver for coagulation factor synthesis. (3) Efficacy at nutritional doses — MK-7 achieves near-complete osteocalcin carboxylation at 100–200 μg/day, whereas MK-4 requires 45 mg/day (450× higher) for comparable extrahepatic effects. (4) Serum accumulation on repeat dosing — MK-7 accumulates 7–8× higher steady-state serum levels than K1, providing consistent tissue-level protection. Additionally, MK-7 is ~10× better absorbed than K1 from dietary sources, and ≥99% all-trans purity ensures maximum biological activity. MK-7 works synergistically with Vitamin D3: D3 enhances intestinal calcium absorption; MK-7 directs that calcium into bone (osteocalcin) and away from arteries (MGP) — the D3 + K2 combination is one of the fastest-growing supplement categories globally.

Recommended daily dosage: 45–180 μg/day for general bone and cardiovascular health; 180–360 μg/day used in clinical trials for targeted therapeutic outcomes. CRN (Council for Responsible Nutrition) has established a highest observed intake level of 375 μg/day. Formulation guidelines: MK-7 is lipophilic (fat-soluble) — for oral supplement formulations, it is typically delivered as an oil suspension (1000–10000 ppm in MCT, olive, or sunflower oil) filled into softgels, or as microencapsulated powder (≥2000 ppm on maltodextrin or gum acacia carrier) for capsules, tablets, and functional food fortification. For liquid formulations, MK-7 oil can be directly incorporated into oil-based carriers. Critical formulation considerations: Protect from light (MK-7 is photosensitive — use opaque or amber packaging and avoid extended light exposure during manufacturing); avoid high-heat processing (temperatures above 40°C may degrade the all-trans isomer to inactive cis forms); include antioxidants (mixed tocopherols or rosemary extract at 0.1–0.5% to protect the polyunsaturated isoprenoid side chain from oxidative degradation); and nitrogen-flush headspace in finished product packaging to minimize oxygen exposure. The gold-standard combination: MK-7 (100–180 μg) + Vitamin D3 (1000–2000 IU) + Calcium (500 mg) for comprehensive calcium homeostasis — D3 drives absorption, MK-7 directs calcium to bone and away from arteries, and calcium provides the mineral substrate.

These three vitamin K forms differ fundamentally in structure, pharmacokinetics, and clinical application. Vitamin K1 (phylloquinone) — plant-derived, single phytyl side chain, ~24-hour half-life, preferentially sequestered by the liver for coagulation factor (II, VII, IX, X) synthesis; minimal extrahepatic (bone/vascular) benefit at dietary doses and poorly absorbed from leafy greens without dietary fat. MK-4 (menatetrenone) — 4-unit unsaturated isoprenoid side chain, ~1.5-hour half-life, undetectable in serum after oral dosing at nutritional levels; used at high pharmaceutical doses (45 mg/day) in Japan as an osteoporosis prescription drug; rapid tissue uptake rather than sustained serum presence may be its mechanism, though high doses are required. MK-7 (menaquinone-7) — 7-unit unsaturated isoprenoid side chain (longest of the three), ~72-hour half-life, preferentially incorporated into LDL/VLDL lipoproteins for systemic extrahepatic distribution to bone and arteries; achieves near-complete osteocalcin and MGP carboxylation at just 100–200 μg/day — 450× lower dose than MK-4 for comparable effect. MK-7 accumulates 7–8× higher steady-state serum levels versus K1 on repeat dosing and is ~10× better absorbed than K1 from dietary sources. The body can endogenously convert K1 and MK-7 into MK-4 in tissues, but this conversion is inefficient and does not substitute for direct MK-7 supplementation. For bone and cardiovascular health at nutritional supplement doses, MK-7 is the clinically and pharmacokinetically superior choice — supported by 3-year RCT data demonstrating reduced arterial stiffness and improved bone mineral density at 180 μg/day.

Every shipment includes: COA (HPLC all-trans isomer purity ≥99.0%, total K2 content assay per labeled potency, full impurity profile with cis-isomer quantification, heavy metals ≤10 ppm with Pb ≤2 ppm / As ≤1 ppm / Hg ≤1 ppm / Cd ≤1 ppm per USP <232>/ICH Q3D, residual solvents per USP <467>/EP <5.4>/ICH Q3C Class 3, microbial panel per USP <61>/<62> and EP <2.6.12>/<2.6.13>), MSDS, HPLC Chromatogram (signed and dated, showing baseline-resolved all-trans and cis isomer peaks), USP/EP Monograph Compliance Statement, BSE/TSE-Free Statement, Non-GMO Statement, Allergen Statement (confirms non-soy, fermentation-derived), HALAL Certificate, KOSHER Certificate, ISO 22000 + HACCP, ISO 9001:2015, FDA Facility Registration, Stability Data (25°C/60%RH real-time 24-month and 40°C/75%RH accelerated 6-month with all-trans isomer retention ≥95%), and Complete Lot Traceability from fermentation batch (Bacillus subtilis natto strain, fermentation conditions, harvest date) to finished product. Free sample available for qualified B2B buyers. MOQ: 1 kg (powder) / 5 kg (oil suspension). All documents provided in English.