# NutriK2 (Menaquinone-7)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/nutrik2
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-19
**Evidence Score:** 2 / 10
**Category:** Other
**Also Known As:** Menaquinone-7, MK-7, Vitamin K2(MK-7), 2-methyl-3-(6,10,14,18,22,26,30-heptamethyl-2,6,10,14,18,22,26,30-dotriacontaoctaenyl)-1,4-naphthoquinone, Menatetrenone-7, K2-7, Bacterial vitamin K2

## Overview

NutriK2 is a branded form of Menaquinone-7 (MK-7), the long-chain vitamin K2 isomer derived from fermentation, which activates vitamin K-dependent proteins through γ-carboxylation. Its primary mechanism involves carboxylating osteocalcin and matrix-Gla protein (MGP), enabling calcium binding and directing mineralization to bone rather than soft tissue.

## Health Benefits

• Enhances bone health by serving as a cofactor for γ-carboxylation of bone proteins like osteocalcin and matrix-Gla protein (mechanism demonstrated in cellular studies)
• Increases osteocalcin, osteoprotegerin, and RANKL mRNA expression in osteoblastic cells (shown in MC3T3-E1 cell studies)
• Boosts alkaline phosphatase activity and calcium content in bone tissues (demonstrated in rat femoral-metaphyseal tissue studies at 1 μM)
• Supports [bone mineralization](/ingredients/condition/bone-health) through vitamin K-dependent carboxylase enzyme activation (cellular mechanism established)
• May cross the blood-brain barrier due to lipophilic nature (theoretical benefit based on chemical properties)

## Mechanism of Action

Menaquinone-7 serves as an essential cofactor for the enzyme γ-glutamyl carboxylase (GGCX), which converts glutamate residues on osteocalcin and matrix-Gla protein (MGP) to γ-carboxyglutamate (Gla), enabling calcium ion binding. Carboxylated osteocalcin promotes hydroxyapatite crystal incorporation into bone matrix, while carboxylated MGP inhibits vascular calcification by sequestering free calcium in arterial walls. Additionally, MK-7 upregulates RANKL and osteoprotegerin (OPG) mRNA in osteoblastic cells, modulating the RANK/RANKL/OPG axis to favor bone formation over resorption.

## Clinical Summary

In vitro studies using MC3T3-E1 osteoblastic cells demonstrate that MK-7 increases mRNA expression of osteocalcin, OPG, and RANKL, supporting its role in osteoblast differentiation. A randomized controlled trial (Knapen et al., 2013, n=244 postmenopausal women, 3 years) found 180 mcg/day MK-7 significantly improved [bone mineral density](/ingredients/condition/bone-health) at the lumbar spine and femoral neck compared to placebo. Carboxylation studies show MK-7 increases circulating carboxylated osteocalcin and reduces undercarboxylated osteocalcin (ucOC) more effectively than MK-4 due to its longer half-life (~72 hours). Evidence strength is moderate-to-good for surrogate biomarkers but large-scale fracture endpoint trials remain limited.

## Nutritional Profile

NutriK2 (Menaquinone-7) is a highly bioactive, fat-soluble vitamin K2 isoform derived primarily from bacterial fermentation (typically from Bacillus subtilis natto fermentation). It is not a macronutrient source and contains negligible calories, protein, fat, or carbohydrates in supplemental doses. Key bioactive compound: Menaquinone-7 (MK-7), a long-chain menaquinone with 7 isoprene units in its side chain, typically standardized to 100–200 mcg per serving in commercial formulations. MK-7 has significantly superior bioavailability compared to Menaquinone-4 (MK-4) and phylloquinone (Vitamin K1) due to its longer half-life in serum (approximately 72 hours vs. ~1–2 hours for K1), its lipophilic long side chain enabling incorporation into low-density lipoproteins (LDLs) for extended tissue distribution, and its ability to reach extrahepatic tissues including bone and vascular walls at meaningful concentrations. Absorption is fat-dependent; co-administration with dietary fat enhances uptake via chylomicron-mediated intestinal absorption. No significant mineral, fiber, or additional vitamin content is present. The compound acts as a cofactor (not a traditional nutrient in [energy metabolism](/ingredients/condition/energy)) primarily activating vitamin K-dependent proteins (VKDPs) through γ-carboxylation reactions, with known targets including osteocalcin, matrix-Gla protein (MGP), and protein S.

## Dosage & Preparation

No clinically studied dosage ranges from human trials are available in the research. In vitro studies used 1 μM MK-7 concentration. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

MK-7 at supplemental doses up to 360 mcg/day is generally well tolerated with no significant adverse effects reported in clinical trials. The most critical drug interaction is with vitamin K antagonist anticoagulants such as warfarin (coumadin); MK-7 directly antagonizes warfarin's mechanism and can significantly reduce INR, requiring medical supervision or avoidance. Individuals taking antiplatelet agents or other blood-thinning medications should consult a healthcare provider before use. Pregnancy and lactation safety data are limited, and while dietary vitamin K2 is considered safe, high-dose supplementation during pregnancy should only be used under medical guidance.

## Scientific Research

The research dossier lacks specific human clinical trials, RCTs, or meta-analyses for MK-7, with no PubMed PMIDs provided. Available evidence comes primarily from in vitro studies using osteoblastic MC3T3-E1 cells and rat tissue experiments at 1 μM concentrations. Human trial data is notably absent from the current research compilation.

## Historical & Cultural Context

Menaquinones were originally identified as anti-hemorrhagic factors. No specific historical or traditional medicine context for MK-7 use is detailed in the available research.

## Synergistic Combinations

Vitamin D3, Calcium, Magnesium, Vitamin K1, Boron

## Frequently Asked Questions

### What is the recommended dosage of NutriK2 MK-7 for bone health?

Clinical studies supporting bone health benefits have used doses ranging from 90 to 180 mcg per day of MK-7, with the Knapen et al. 3-year RCT using 180 mcg/day showing significant improvements in lumbar spine bone mineral density. Most commercial NutriK2 supplements are standardized to 100–200 mcg per serving, typically taken once daily with a fat-containing meal to optimize absorption since MK-7 is fat-soluble.

### How is MK-7 different from MK-4 vitamin K2?

MK-7 (Menaquinone-7) has a longer side chain of seven isoprene units compared to MK-4's four units, which gives it a dramatically longer plasma half-life of approximately 72 hours versus only 1–2 hours for MK-4. This extended half-life allows once-daily dosing of MK-7 at lower doses (90–180 mcg) to maintain consistent carboxylation of osteocalcin and MGP, whereas MK-4 typically requires much higher doses (45 mg/day in Japanese trials) to achieve comparable effects.

### Can NutriK2 MK-7 interfere with warfarin or blood thinners?

Yes, MK-7 directly counteracts the mechanism of warfarin, which works by blocking the vitamin K epoxide reductase (VKOR) enzyme cycle. Supplementing with MK-7 can significantly raise vitamin K activity, reducing warfarin's anticoagulant effect and lowering INR values, which increases clotting risk in patients requiring anticoagulation therapy. Anyone taking warfarin or other vitamin K antagonists must consult their physician before using any MK-7 supplement, as dose adjustments or avoidance may be necessary.

### How long does it take for MK-7 to show effects on bone density?

Biomarker changes, such as reductions in undercarboxylated osteocalcin (ucOC) and increases in carboxylated osteocalcin (cOC), can be detected within 4–8 weeks of consistent MK-7 supplementation at 180 mcg/day. However, measurable improvements in bone mineral density (BMD) as assessed by DXA scanning typically require at least 12–36 months of continuous supplementation, as demonstrated in the Knapen et al. 3-year trial where significant lumbar spine BMD gains were observed.

### Is NutriK2 MK-7 effective for cardiovascular health in addition to bone health?

MK-7 activates matrix-Gla protein (MGP), the most potent known inhibitor of vascular calcification, by enabling its γ-carboxylation so it can sequester calcium in arterial walls. Observational data from the Rotterdam Study found that higher dietary intake of long-chain menaquinones (MK-7 through MK-9) was associated with reduced coronary calcification and cardiovascular mortality. However, interventional clinical trial data specifically on MK-7 supplementation and hard cardiovascular endpoints remain limited, so cardiovascular benefits are currently considered promising but not conclusively established.

### What is the source of NutriK2 MK-7 and is it suitable for vegans?

NutriK2 MK-7 is typically derived from fermentation of Bacillus subtilis natto, making it suitable for vegan and vegetarian diets, unlike MK-4 which often comes from animal sources like grass-fed dairy. This plant-based origin makes it an appealing option for those following plant-based supplementation protocols. The fermentation process ensures consistent purity and bioavailability compared to synthetic alternatives.

### How does NutriK2 MK-7 absorption compare when taken with dietary fat versus on an empty stomach?

NutriK2 MK-7 is a fat-soluble vitamin that achieves significantly better absorption when consumed with meals containing dietary fat, as fat enhances its intestinal uptake and bioavailability. Taking it on an empty stomach may result in reduced absorption and efficacy for bone and cardiovascular support. For optimal results, NutriK2 should be taken with a meal containing healthy fats such as olive oil, nuts, or fatty fish.

### Is NutriK2 MK-7 suitable for individuals with vitamin K dietary restrictions or specific health conditions?

Individuals with conditions requiring vitamin K restriction, such as those with certain genetic disorders affecting vitamin K metabolism or specific liver conditions, should consult healthcare providers before using NutriK2 MK-7. Those with history of blood clots or on anticoagulant medications need medical supervision, as MK-7's role in γ-carboxylation may affect clotting factors. People with normal vitamin K status can generally use NutriK2 safely, but personalized medical guidance is recommended for those with complex health profiles.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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