ByDr. Brennan Commerford, Chiropractic Physician·Last reviewed: April 2026
All Ingredients
Vitamin1 form

Vitamin K1

Evidence Level
Moderate Evidence

Quick Answer

What is the best form of Vitamin K1?

We compared 1 forms of Vitamin K1 in our formulary. Browse the comparison table below to find the best form for your goals.

1forms compared

All Forms of Vitamin K1

FormTierBioavailabilityDose RangeUnit
PhylloquinoneT2 SpecialistS2

Bioavailability by Form

S2 — Good
Phylloquinone

What is Vitamin K1?

Vitamin K1 is a Vitamin supplement available in 1 form.

Not all forms of Vitamin K1 are equal. The form you choose determines how much Vitamin K1 actually reaches your tissues, and the difference between the best and worst forms can be substantial. Vitamin K1 (phylloquinone) is the dietary form of vitamin K found in green leafy vegetables that primarily supports hepatic coagulation factor synthesis. Research supports vitamin K1 for promoting healthy blood coagulation protein activation and bone osteocalcin activity, serving as a foundational K vitamin alongside K2 forms.

Forms of Vitamin K1 Compared

Vitamin K1 (T2 Specialist) has a bioavailability rating of good (S2). Typical dose range: not yet documented in our database.

What the Research Shows

Vitamin K1 (phylloquinone) is the primary dietary form of vitamin K, predominantly found in green leafy vegetables. It is the form most directly involved in hepatic synthesis of clotting factors. While MK-7 has superior extrahepatic activity, K1 remains clinically important for individuals on anticoagulant therapy requiring precise dosing management.

How to Choose the Right Form

Multiple forms of Vitamin K1 are available. Start by comparing formulary tiers — T1 Preferred forms reflect the strongest bioavailability evidence, and S1-rated forms deliver the most active compound per dose unit.

The appropriate form depends on your individual goals and your healthcare provider’s recommendations. Consult a qualified professional before selecting a supplement form.

Dosing & Safety

For Vitamin K1, the typical dosing range is not yet documented in our database. Individual dose requirements vary based on health goals, body weight, and existing nutrient intake.

Side Effects: Specific side effect data for these forms is not yet documented in our database. In general, consult your healthcare provider regarding tolerability at higher doses.

These statements are based on structure/function research and have not been evaluated by the FDA. This information is not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare provider before starting or changing a supplement regimen.

Dosing Guidance

Dosing information not yet available for this ingredient.

Frequently Asked Questions

What is the best form of Vitamin K1?
Multiple forms of Vitamin K1 are available, each with different absorption characteristics. Our formulary classification data for Vitamin K1 is being compiled. Always consult a qualified healthcare provider before starting, stopping, or adjusting any supplement regimen.
How much Vitamin K1 should I take daily?
Dosing information for Vitamin K1 is being compiled in our database. Individual dose requirements vary based on health goals and existing nutrient intake. Always consult a qualified healthcare provider before starting, stopping, or adjusting any supplement regimen. These statements are based on structure/function research and have not been evaluated by the FDA. This information is not intended to diagnose, treat, cure, or prevent any disease.
What are the benefits of Vitamin K1?
Vitamin K1 has been studied for its role in supporting: Supports healthy blood clotting and coagulation cascade, Supports bone health and calcium metabolism, Supports cardiovascular health. Vitamin K1 (phylloquinone) is the primary dietary form of vitamin K, predominantly found in green leafy vegetables. It is the form most directly involved in hepatic synthesis of clotting factors. While MK-7 has superior extrahepatic activity, K1 remains clinically important for individuals on anticoagulant therapy requiring precise dosing management. These statements are based on structure/function research and have not been evaluated by the FDA. This information is not intended to diagnose, treat, cure, or prevent any disease.
When is the best time to take Vitamin K1?
Optimal timing for Vitamin K1 supplementation depends on the specific form, dosage, and individual factors. Some forms may be better absorbed with food; others may not require food. Always consult a qualified healthcare provider before starting, stopping, or adjusting any supplement regimen.
Are there side effects of taking Vitamin K1?
Tolerability of this Vitamin supplement varies by individual, dose, and specific form. Some individuals may experience gastrointestinal discomfort at higher doses. Specific side effect profiles for each form of Vitamin K1 are documented in our formulary where available. Always consult a qualified healthcare provider before starting, stopping, or adjusting any supplement regimen. These statements are based on structure/function research and have not been evaluated by the FDA. This information is not intended to diagnose, treat, cure, or prevent any disease.
What forms of Vitamin K1 are available?
There are 1 form of Vitamin K1 in our formulary: Vitamin K1 (T2 Specialist, bioavailability: good (S2)). Forms differ in chemical structure, bioavailability, and typical dose range. FormulaForge classifies forms by tier based on published bioavailability evidence.

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FormulaForge formulates and sells supplements containing the ingredients discussed on this page. Our formulary recommendations are based on peer-reviewed bioavailability research. All cited studies are independently verifiable.