Vitamin K2

Effects and Benefits

Core Identification

Common Names:
- Vitamin K2
- Menaquinone
- MK-4 (menaquinone-4)
- MK-7 (menaquinone-7)

Latin Name: N/A (isolated nutrient)

Category: Vitamin

Uses

Traditional Uses

• Natto consumption for longevity - Japanese dietary tradition for centuries
• Fermented food consumption for bone and heart health - Asian cultures

Modern Uses

• Bone Health & Osteoporosis Prevention - Directs calcium into bones and activates osteocalcin | Research quality: Strong
• Key findings: 2013 Osteoporosis International study found supplemental K2 taken over three years significantly improved bone density and strength in postmenopausal women; supplements can reduce loss of bone calcium by up to 50% and strengthen weakened bones; higher vitamin K2 intake linked to 63% lower risk of prostate cancer in study of 11,000 men

• Source citations: Osteoporosis International (2013); Brewer - Encyclopedia of Vitamins; American Journal of Clinical Nutrition; Better Nutrition 2017-06

• Cardiovascular Health & Arterial Calcification Prevention - Removes calcium from arteries and prevents plaque buildup | Research quality: Strong

• Key findings: K2 activates matrix Gla-protein (MGP), which inhibits vascular calcification; higher K2 intake corresponds to less calcium deposition in aorta; helps prevent "hardening of the arteries" (atherosclerosis); addresses the calcium paradox where D3 without K2 deposits calcium in soft tissues

• Source citations: Advanced Nutrition (2012); Amazing Wellness 2016-01; Dr. Dennis Goodman - Vitamin K2: The Missing Nutrient for Heart and Bone Health

• Calcium Metabolism Optimization - Works synergistically with D3 to properly direct calcium | Research quality: Strong

• Key findings: K2 helps calcium bind to bone mineral matrix while keeping it away from blood vessels; vitamin D3 helps put calcium into bones but without K2 also places calcium into soft tissue; this is known as the "calcium paradox"

• Source citations: Amazing Wellness 2016-01; Better Nutrition 2017-02

• Dental Health - Supports proper tooth mineralization | Research quality: Preliminary

• Key findings: K2 deficiency manifests as dental cavities; proper K2 levels support dental remineralization
• Source citations: Amazing Wellness 2016-01

Active Compounds

Primary Active Ingredients:
- Menaquinone-4 (MK-4) - Short-chain form found in animal products; rapidly absorbed but short half-life; activates vitamin K-dependent proteins
- Menaquinone-7 (MK-7) - Long-chain form from bacterial fermentation (especially natto); longer half-life providing more sustained blood levels; preferred supplemental form for cardiovascular and bone health

Dosage Information

Standard Dosage:
- Form: Capsule or soft gel
- Amount: 45-100 mcg per day
- Frequency: Once daily with a meal containing fat

Therapeutic Dosage:
- Form: Capsule (MK-7 form preferred)
- Amount: 150-180 mcg per day (some practitioners recommend up to 300 mcg)
- Purpose: For bone health support, cardiovascular protection, or those taking vitamin D3
- Duration: Ongoing; particularly important when supplementing with vitamin D3 or calcium

Maximum Safe Dosage:
- Daily maximum: No established upper limit; doses up to 300 mcg MK-7 used safely in studies
- Warning threshold: Natural forms K1 and K2 appear completely safe; no known toxicity at supplemental doses

Bioavailability Notes:
- Fat-soluble vitamin requiring dietary fat for optimal absorption
- MK-7 form has longer half-life (several days) compared to MK-4 (hours)
- Unlike K1, vitamin K2 is NOT recycled in the body, making dietary/supplemental intake crucial
- Best absorbed when taken with meals containing fat

How to Take It

Timing:
- With meals for optimal absorption
- Take with food containing fat (oils, dairy, meat)
- If taking with D3 and calcium, take together for synergistic effect
- Morning or evening; consistency matters more than specific timing

Synergies - What It Works Well With

Complementary Supplements:
1. Vitamin D3 - Essential pairing; D3 increases calcium absorption while K2 directs it to bones and away from arteries; prevents the calcium paradox
2. Calcium - K2 ensures calcium is deposited in bones rather than arteries and soft tissues
3. Magnesium - Natural calcium channel blocker; supports balanced mineral metabolism with K2
4. Vitamin K1 - Complements K2; K1 handles blood clotting while K2 focuses on calcium metabolism

Avoidance - What NOT to Combine With

Supplement Interactions:
1. High-dose Vitamin E - Very high doses may theoretically interfere with vitamin K activity, though clinical significance is debated

Drug Interactions:
1. Warfarin (Coumadin) - Vitamin K2 can interfere with anticoagulant effect; requires medical supervision to maintain stable INR | Severity: Severe
2. Other Vitamin K-Dependent Anticoagulants - May reduce effectiveness of blood thinners | Severity: Severe
3. Antibiotics (broad-spectrum) - Studies show broad-spectrum antibiotics lower liver concentrations of vitamin K2 (menaquinone) while K1 levels remain normal; may require supplementation | Severity: Moderate
4. Orlistat (weight loss drug) - May reduce absorption of fat-soluble vitamins including K2 | Severity: Mild to Moderate

Food Interactions:
- No specific foods to avoid
- Individuals on warfarin should maintain consistent K intake and consult physician before supplementing

Safety Information

Contraindications:
- Individuals on warfarin or vitamin K-dependent anticoagulant therapy should not supplement without medical supervision
- Those with blood clotting disorders being managed with anticoagulants

Side Effects:
- No known toxicity from vitamin K2 at typical supplemental doses
- Natural forms K1 and K2 appear completely safe
- A very small percentage (4%) may experience minor digestive upset (based on ginger vs. K2 comparative study parameters)
- Note: Synthetic vitamin K3 (menadione) can interfere with glutathione function and should be avoided

Long-Term Use:
- Considered safe for long-term use
- No established upper limit for K2
- Particularly beneficial for ongoing use alongside vitamin D3 supplementation
- Those on anticoagulant therapy require medical monitoring

Special Precautions:
- Surgery: Inform surgeon of vitamin K2 supplement use
- Pregnancy: Generally considered safe; consult healthcare provider
- Individuals taking calcium or vitamin D3 supplements: K2 is recommended to ensure proper calcium utilization
- Kidney disease: May be especially important as suboptimal vitamin K levels contribute to vascular calcification in this population

Primary Uses At-a-Glance

Primary: Bone health, cardiovascular health, arterial calcification prevention, calcium metabolism optimization

Secondary: Dental health, diabetes prevention, working synergistically with vitamin D3, post-menopausal bone density support

Sources

Local Library:
- Brewer, Sarah - TDT Encyclopedia of Vitamins
- Moline, Peg - The Doctors Book of Natural Health Remedies
- Gaby, Alan R. - A-Z Guide to Drug-Herb-Vitamin Interactions 2nd Ed
- Moyad, Mark - The Supplement Handbook
- Stewart, Martha - Living the Good Long Life
- Wilen, Lydia - Healing Remedies
- Balch, Phyllis - Prescription for Herbal Healing
- Bartram, Thomas - Encyclopedia of Herbal Medicine
- Amazing Wellness Magazine (2016-01) - "Special K" article by Emily Kane, ND, and sidebar by Dennis Goodman, MD
- Better Nutrition Magazine (2017-02, 2017-06, 2018-02)
- Mother Earth News 2019

General Knowledge:
- Osteoporosis International (2013)
- Advanced Nutrition (2012)
- American Journal of Clinical Nutrition
- Dr. Dennis Goodman - Vitamin K2: The Missing Nutrient for Heart and Bone Health