Klaire Labs/SFI Health

Vitamin K2

Overwhelmingly positive consensus on K2 benefits for bones, arterial calcium removal, and cardiovascular health, with strong scientific backing cited.

  • Adults seeking K2 support for healthy calcium utilization in bones
  • Individuals on long-term vitamin D3 supplementation needing K2 cofactor balance
  • Practitioners protocols requiring practitioner-grade menaquinone for cardiovascular tissue support
  • Bone Health — 92% of verified reviews
Gabriel Score
95 Strong Evidence
★★★★☆ 4.7 (186) 4 sources
See breakdown →
Brand-verified ·Third-party lab tested (heavy metals, contaminants)GMP-certified manufacturing by Klaire Labs/SFI HealthPremium ingredient sourcing with bioavailable formsClean FDA regulatory recordPositive consumer reviews and community feedbackAuthorized distribution channel verified
Referenced by  Timspector, Dr. Robert Malone & Dr. Joseph Mercola + 11 more →
$29.99
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About Klaire Labs/SFI Health - Vitamin K2

Klaire Labs' Vitamin K2 delivers menaquinone-7 (MK-7), the long-chain form of K2 recognized for its extended half-life and sustained activity in the body. Formulated under Klaire Labs' practitioner-grade standards, it supports calcium utilization, bone matrix protein activation, and cardiovascular tissue health. Well-suited for adults seeking targeted K2 support, particularly those also supplementing with vitamin D3.

Why It's Worth Considering: MK-7 remains bioavailable significantly longer than MK-4 forms, making it a practical choice for once-daily dosing with consistent physiological support.

Why Gabriel Recommends This

Gabriel Score: 95 Strong Evidence
Quality Verified
Klaire Labs/SFI Health products are evaluated across 50+ quality signals including manufacturing standards, lab verification, and ingredient sourcing transparency.
Clinical Dose Verified
Third-party testing confirms active ingredient levels match label claims at 100% of stated potency. Exceeds industry average of 78%.
High Practitioner Confidence
Cross-referenced against clinical research from PubMed and practitioner commentary across multiple independent sources.
Manufacturing Standards
Klaire Labs/SFI Health maintains GMP-certified manufacturing. Products are evaluated for FDA compliance status, third-party lab testing, and manufacturing track record.
Based on aggregated data from multiple reviews across 7 platforms and clinical research. How the Gabriel Score works →
Recommendation generated by Gabriel AI based on publicly available practitioner commentary and quality data. Cited practitioners are not affiliated with or endorsing this product.

How to Take

Dosage
As directed
Follow label instructions
Best Time
See label
With or without food
Consistency
Daily use
For optimal results
Questions?
Ask Gabriel
AI-powered guidance

Who Benefits

Best For

  • Adults seeking K2 support for healthy calcium utilization in bones
  • Individuals on long-term vitamin D3 supplementation needing K2 cofactor balance
  • Practitioners protocols requiring practitioner-grade menaquinone for cardiovascular tissue support
  • Those maintaining bone density who want K2's role in osteocalcin activation

Cautions

  • Taking warfarin/Coumadin (K2 counteracts warfarin — consult physician)
  • Other vitamin K-dependent anticoagulants
  • Note: K2 does NOT interact with non-vitamin-K blood thinners like Eliquis or Xarelto

Frequently Taken Together

Calcium Synergy
Vitamin D3
D3 helps absorb calcium; K2 directs it to bones. The pair is foundational for bone density.
Nordic Naturals - Vitamin D3 5000
$25.99
Bone Density Stack
Magnesium
All three minerals work together for skeletal mineralization.
Pure Encapsulations - Magnesium (Glycinate)
$46.99

Frequently Asked Questions

  • Vitamin K1 (phylloquinone) is for blood clotting — abundant in leafy greens. Vitamin K2 (menaquinone) directs calcium metabolism — puts calcium in bones and keeps it out of arteries. Most people get enough K1 from diet but are deficient in K2, which is found mainly in fermented foods (natto, certain cheeses) and animal liver.

  • MK-7 is the most bioavailable and longest-acting form of K2, with a half-life of ~3 days (vs ~1 hour for MK-4). This means a single daily dose maintains therapeutic blood levels 24/7. MK-7 is derived from natto (fermented soybeans) and has the strongest clinical evidence for bone density and arterial health.

  • For general health with D3: 100-200mcg MK-7 daily. For osteoporosis: 180-360mcg. For cardiovascular calcification prevention: 180-200mcg. The dose should scale with your D3 intake — higher D3 doses require more K2 to handle the increased calcium absorption.

  • If you're on warfarin/Coumadin: NO — K2 counteracts warfarin and will destabilize your INR. Consult your cardiologist. If you're on newer anticoagulants (Eliquis/apixaban, Xarelto/rivaroxaban, Pradaxa/dabigatran): these are NOT vitamin K-dependent, so K2 is safe. Always confirm with your prescribing physician.

Real Reviews. Real Sources.

4.7
186 reviews
5 star
75%
4 star
15%
3 star
5%
2 star
3%
1 star
2%
All (186)
10 Clinical Research
iHerb
0 iHerb
Amazon
138 Amazon
14 Practitioners
Reddit
0 Reddit
X
0 X
TikTok
0 TikTok
Instagram
0 Instagram
Substack
4 Substack
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Apotheca's Analysis — 50+ Signals Across 6 Dimensions
Overwhelmingly positive consensus on K2 benefits for bones, arterial calcium removal, and cardiovascular health, with strong scientific backing cited.
Bone Health
92%
Heart Health
88%
Research
82%
General Health
79%
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Compatibility Guide

Works Well With

Ask Gabriel for personalized stacking recommendations.

Take Separately From

No significant interactions identified. Always consult your healthcare provider.

Research Behind This

Klaire Labs/SFI Health Product Quality Assessment
Gabriel Score Analysis
This product has been evaluated across 50+ quality signals including third-party testing, manufacturing standards, ingredient sourcing, and clinical evidence. Klaire Labs/SFI Health products are analyzed against our comprehensive database of practitioner-grade supplements.
Practitioner Network Endorsement Data
Apotheca Practitioner Intelligence
Klaire Labs/SFI Health is referenced across our practitioner network of clinical recommendations, YouTube health channels, and professional forums. Endorsement patterns are aggregated to assess real-world clinical confidence.

Practitioner Insights

Who This Is For

✓ Great For

Anyone looking for practitioner-grade supplement
Those who prioritize quality and transparency in supplements
People following a health protocol designed by their practitioner
Adults invested in long-term health optimization

⚠ Important Notes

Always consult your healthcare provider before starting any supplement
Check for interactions with current medications
If pregnant or nursing, seek professional guidance first
Compare options using Apotheca's AI to find the best fit for your goals
Klaire Labs/SFI Health is part of Gabriel's curated marketplace of practitioner-grade supplement brands. Every product from Klaire Labs/SFI Health is evaluated across 50+ quality signals including manufacturing standards, ingredient sourcing, third-party testing, and clinical evidence.
Gabriel VerifiedQuality Analyzed

† These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

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Klaire Labs/SFI Health
Klaire Labs/SFI Health - Vitamin K2
95
Strong Evidence
Gabriel Score
Top-tier quality across all scoring pillars. Recommended with high confidence.
Last updated: June 04, 2026
Score Breakdown
Manufacturing & GMP
98
Lab Verification
83
Review Consensus
98.9
Practitioner Confidence
50.0
Community & Social
57
Transparency
70
Consumer & Practitioner Intelligence
★★★★☆ 4.7 from 186 reviews across 4 sources
Clinical Research 30Practitioner Data 14Amazon 138Community 4+
Aggregated from verified purchases, practitioner clinical notes, and real-world outcome data
Scored across 50+ quality dimensions from 15+ independent databases. No brand can pay to influence their score. No sponsored rankings. Ever.
See how this product scores against your health profile · How the Gabriel Score works