Vitamin K1 (Phylloquinone) vs Vitamin K2 (MK-9)
Two forms of the same compound. What differs is how much of it your body absorbs, how well you tolerate it and what it costs per month.
Side by side
Green marks the better value| Vitamin K1 (Phylloquinone) | Vitamin K2 (MK-9) | |
|---|---|---|
| Bioavailability | 80% | 85% |
| Safety rating | 9/10 | 7/10 |
| Cost per month | $8 | $120 |
| Daily dose | 90-120 mcg | 50-200 mcg (experimental) |
| Best timing | With fat meal | With fat containing meal |
| Evidence level | A | C |
Verdict
Vitamin K1 (Phylloquinone) wins on 2 of the measurable metrics.
It absorbs at 80% against 85%, which is the number that decides how much of the dose actually reaches you.
What actually differs
Vitamin K1 (Phylloquinone)
Essential vitamin primarily responsible for blood clotting and found abundantly in green leafy vegetables
- Natural form
- Well-absorbed
- Safe profile
- Short half-life
- Requires fat for absorption
Vitamin K2 (MK-9)
Long-chain menaquinone with extended half-life and unique tissue distribution patterns
- Extended half-life
- Unique properties
- Advanced technology
- Sustained action
- Extremely limited research
- Very expensive
- Minimal availability
- Unproven benefits
How these numbers are read
- Bioavailability is the share of the dose that reaches your bloodstream — the single most useful number when choosing a form.
- Safety rating reflects tolerance at normal doses, not toxicity risk.
- Cost is per month at the typical daily dose, so a cheaper form taken at double the dose is not cheaper.
- Evidence level A means the form itself was studied, not just the parent compound.
Where to buy
Both forms deliver the same compound — pick by the numbers above, then check the label matches.
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Common questions
Which is better, Vitamin K1 (Phylloquinone) or Vitamin K2 (MK-9)?
Vitamin K2 (MK-9) absorbs better — 85% against 80%. Absorption decides how much of the dose actually reaches you, so it usually matters more than the milligrams printed on the label.
What is the difference between Vitamin K1 (Phylloquinone) and Vitamin K2 (MK-9)?
Both deliver the same active compound. They differ in how well the body takes them up, how they are tolerated and what a month costs: $8 against $120.
Can you take Vitamin K1 (Phylloquinone) and Vitamin K2 (MK-9) together?
You can, but there is rarely a reason to. Two forms of the same compound stack the same active dose, so the usual approach is to pick the better absorbed one and dose it properly.