Vitamin D3+K2 Cofactor Complex, 60 Capsules
Neurobiologix Vitamin D3+K2 Cofactor Complex pairs cholecalciferol (D3) with menaquinone (K2) to support calcium metabolism, bone density maintenance, and cardiovascular health.
May be a fit for
- Adults seeking D3 and K2 together for calcium utilization support
- Individuals with limited sun exposure looking to maintain D3 levels
- Those supporting bone matrix health with vitamin K2 MK-7 activity
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Neurobiologix Vitamin D3+K2 Cofactor Complex pairs cholecalciferol (D3) with menaquinone (K2) to support calcium metabolism, bone density maintenance, and cardiovascular health. This combination is formulated for individuals seeking to optimize vitamin D absorption while supporting proper calcium utilization in the body.
Why It's Worth Considering: Combining D3 with K2 addresses a key nutritional synergy, K2 helps direct calcium toward bones and away from soft tissues, making this pairing more functional than D3 alone.
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Product details
Who it may suit
May be a fit for
- Adults seeking D3 and K2 together for calcium utilization support
- Individuals with limited sun exposure looking to maintain D3 levels
- Those supporting bone matrix health with vitamin K2 MK-7 activity
- People seeking cofactor pairing to complement existing magnesium protocols
Considerations
- Hypercalcemia (elevated blood calcium)
- Sarcoidosis or other granulomatous diseases
- Severe kidney disease without medical supervision
- Taking thiazide diuretics (monitor calcium)
Compatibility & interactions
Works Well With
Take Separately From
No significant interactions identified. Always consult your healthcare provider.
What to expect over time
Serum Levels Rise
Measurable increase in 25(OH)D
Immune Support
Improved innate immune function
Mood & Energy
Reduced fatigue and improved mood
Optimal Range
Target 50-80 ng/mL achieved
Based on clinical studies on vitamin D3 supplementation. Response varies by baseline levels, body weight, and skin tone.
Compare the options
Compare Vitamin D Forms
D3 vs D2 vs D3+K2
| Feature | D3 (Cholecalciferol) | D2 (Ergocalciferol) | D3 + K2 Combo |
|---|---|---|---|
| Source | Animal (lanolin/lichen) | Plant/fungal | Animal + bacterial |
| Potency | 87% more effective at raising serum D | Baseline | Same as D3 + K2 synergy |
| Half-Life | ~2-3 weeks | ~2-3 days | ~2-3 weeks |
| Best For | General supplementation | Vegan-only option | Bone + cardiovascular health |
| Evidence | Strong (gold standard) | Moderate | Strong (synergistic) |
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180 product and brand ratings and mentions across 4 sources.
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Explore the source sentiment summary
Generally positive view of D3+K2 combination for immune and bone health, with notable debate around optimal dosing vs. official guidelines.
This summary includes broader brand discussion. Individual experiences are not evidence of product effectiveness.
A few useful answers.
Research & further reading
More category questions
How much vitamin D3 should I take daily?
Most functional medicine practitioners recommend 5,000 IU daily for adults with normal BMI, and up to 10,000 IU for those with obesity or severe deficiency. The Endocrine Society recommends maintaining serum 25(OH)D levels between 40-60 ng/mL. Test your levels every 3-6 months.
Is vitamin D3 better than D2?
Yes. D3 (cholecalciferol) is 87% more effective at raising and maintaining serum vitamin D levels compared to D2 (ergocalciferol). D3 also has a longer half-life. D2 is only preferred by strict vegans who cannot use lanolin-sourced D3 — lichen-based D3 is the vegan alternative.
Should I take vitamin D3 with vitamin K2?
Yes, especially at doses above 2,000 IU. Vitamin D3 increases calcium absorption from food. Without K2, that calcium can deposit in arteries instead of bones. K2 (MK-7 form) activates osteocalcin (puts calcium in bones) and matrix GLA protein (keeps calcium out of arteries).
Can I take too much vitamin D?
Toxicity is rare below 10,000 IU/day in healthy adults but possible with chronic high-dose use without monitoring. Symptoms of excess include hypercalcemia (nausea, kidney stones, confusion). Always pair high-dose D3 with K2 and test 25(OH)D levels every 3-6 months.
When is the best time to take vitamin D3?
Take with your largest meal containing fat — D3 is fat-soluble and absorption increases 30-50% when taken with dietary fat. Morning or afternoon is preferred over evening, as some studies suggest late-night D3 may interfere with melatonin production.
How long does it take for vitamin D levels to increase?
Serum 25(OH)D typically rises within 1-2 weeks of supplementation. Reaching optimal range (50-80 ng/mL) takes 2-3 months at 5,000 IU/day from a deficient baseline. Higher loading doses (10,000 IU for 8 weeks then maintenance) can accelerate this.
Supplement information is provided for education and is not a substitute for personalized medical advice. Supplements are not intended to diagnose, treat, cure or prevent disease. Read the current product label before use.