Vitamin K2 (MK-4) vs Vitamin K2 (MK-7)
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 K2 (MK-4) | Vitamin K2 (MK-7) | |
|---|---|---|
| Bioavailability | 60% | 80% |
| Safety rating | 9/10 | 9/10 |
| Cost per month | $35 | $25 |
| Daily dose | 15-45 mg (divided doses) | 100-200 mcg |
| Best timing | Multiple doses with fat | With fat meal |
| Evidence level | B | B |
Verdict
Vitamin K2 (MK-7) wins on 2 of the measurable metrics.
It absorbs at 80% against 60%, which is the number that decides how much of the dose actually reaches you.
What actually differs
Vitamin K2 (MK-4)
Short-chain vitamin K2 form with rapid action but shorter duration, used in Japanese osteoporosis treatment
- Fast-acting
- Proven in osteoporosis
- Multiple dosing flexibility
- Animal-derived
- Short half-life
- Multiple daily doses needed
- More expensive
- Less convenient
Vitamin K2 (MK-7)
Essential vitamin for proper calcium utilization, bone health, and cardiovascular protection
- Longest half-life
- Best studied
- Most bioactive
- More expensive than K1
- Limited food sources
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 K2 (MK-4) or Vitamin K2 (MK-7)?
Vitamin K2 (MK-7) absorbs better — 80% against 60%. 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 K2 (MK-4) and Vitamin K2 (MK-7)?
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: $35 against $25.
Can you take Vitamin K2 (MK-4) and Vitamin K2 (MK-7) 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.