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Vitamins & MultivitaminsModerate Evidence3rd Party Tested

Vitamin K2

Also known as: Menaquinone, MK-4, MK-7, Menaquinone-7

The calcium traffic director that protects arteries and builds bone

7/10 Evidence Score

Primary Benefit

Bone Density and Arterial Health

Standard Dose

90 to 200 mcg/day MK-7

Evidence

Certifications

USP Verified

Overview

Vitamin K2 (menaquinone) is a fat-soluble vitamin that activates proteins responsible for directing calcium to bones and teeth and away from soft tissues like arteries. It is distinct from K1 (phylloquinone), which governs blood clotting. K2 deficiency leaves these calcium-regulating proteins inactive, contributing to arterial calcification and osteoporosis simultaneously.

Benefits & Evidence

  • Activates osteocalcin to bind calcium into bone matrix
  • Activates Matrix Gla Protein (MGP) to prevent arterial calcification
  • Works synergistically with vitamin D3 for bone and cardiovascular health
  • May reduce fracture risk with long-term supplementation
  • Supports dental health via carboxylated osteocalcin

Clinical Study Summaries

Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women

2013

Osteoporosis International

MK-7 supplementation at 180 mcg/day for 3 years significantly improved bone strength and reduced age-related bone loss in post-menopausal women versus placebo.

View study

Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women

2015

Thrombosis and Haemostasis

Daily MK-7 supplementation for 3 years activated MGP and significantly reduced age-related arterial stiffness, suggesting a cardiovascular protective role.

View study

Recommended Dosage

Standard Dose90 to 200 mcg/day MK-7
Minimum45 mcg/day
Maximum360 mcg/day
TimingWith a fat-containing meal for absorption
Notes: MK-7 has a longer half-life (3 days vs 1 hour) than MK-4 and reaches higher stable blood levels. Best taken alongside Vitamin D3. MK-4 requires multiple higher doses (1,500 mcg 3x daily) to match MK-7 efficacy.

Side Effects & Interactions

Potential Side Effects
  • Extremely well tolerated
  • No known toxicity at supplemental doses
Drug & Nutrient Interactions
  • Warfarin and anticoagulants (K2 can reduce anticoagulant effectiveness, avoid without physician guidance)
  • Vitamin D3 (synergistic, recommended to take together)

Who Should Consider It

Good candidates

  • Anyone supplementing with Vitamin D3
  • Post-menopausal women concerned about bone density
  • People with risk factors for arterial calcification
  • Those on high-calcium diets wanting to ensure proper calcium utilization

Use caution or avoid

  • Those on warfarin or other vitamin K-antagonist anticoagulants without physician guidance
Medical Disclaimer

This information is for educational purposes only. It does not constitute medical advice. Consult a qualified healthcare professional before starting any supplement, especially if you have health conditions or take medications.

Third-Party Testing

This supplement has products available with independent quality verification.

USP Verified
Evidence Breakdown
Overall Score7/10
Popularity7/10

Evidence Level

Moderate

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