Most adults get 90–120 µg of vitamin K daily; no set K2 dose, but studies often use 45–180 µg per day.
Quick note on units: labels for vitamin K2 use micrograms (µg), not milligrams (mg). One milligram equals 1,000 micrograms. So “1 mg” means 1,000 µg.
What Daily Vitamin K2 Amounts Do Studies Use?
Public agencies publish targets for total vitamin K, not a separate target for menaquinones. In the United States, adult AIs sit at 120 µg for men and 90 µg for women. Europe uses a weight-based AI near 1 µg per kilogram of body weight. Research on menaquinone-7 (MK-7) often tests 45–180 µg per day. These trials look at carboxylation markers, bone metrics, and vascular stiffness over months or years.
| Source Or Context | Intake | What It Covers |
|---|---|---|
| NIH (U.S.) Adequate Intake | Men 120 µg/day; Women 90 µg/day | Total vitamin K from food and supplements; not K2 alone |
| EFSA Adequate Intake | ~1 µg/kg/day | Total vitamin K for adults; weight-based |
| Typical MK-7 Trial Arms | 45–180 µg/day | Used to track vitamin K–dependent protein status and bone or vascular outcomes |
Why The Label Says “µg,” Not “mg”
Menaquinone is potent at tiny amounts. Many high-street products sit at 90, 100, 120, 150, or 180 µg of MK-7 per capsule. A full milligram is far above common trial arms. That’s why labels use micrograms.
Daily Vitamin K2 Amounts: What Fits Real Life
Diet first. Leafy greens carry phylloquinone, while fermented foods and aged cheese carry menaquinones. Natto is the standout food for MK-7. Cheeses vary by style and culture strains. Some weeks your menu covers intake; other weeks a small MK-7 capsule keeps things steady. Many human studies land between 45 and 180 µg per day.
Food Sources That Contribute K2
Natto can deliver hundreds of micrograms of MK-7 in a single serving. Aged cheeses supply mostly longer-chain forms such as MK-8 and MK-9, with broad variation by ripening time and starter cultures. Eggs and poultry add small amounts.
Research Snapshot On Outcomes
Long trials in postmenopausal women used 180 µg of MK-7 daily for three years. Some papers noted changes in strength indices or vascular stiffness. Others did not find clear shifts in bone mineral density. Mixed results may reflect dose, baseline status, and co-nutrients.
How To Think About A Personal Range
Start with food. If your menu rarely includes natto or aged cheese, an MK-7 product in the 90–180 µg range can help. Pick a steady time.
Who Should Be Careful
People who use warfarin need stable vitamin K intake. Sudden shifts—whether from natto bowls or new capsules—can change INR. Any change in intake should be coordinated with the prescribing clinic so dose and labs stay aligned. People with bleeding disorders, upcoming surgery, or rare fat-absorption conditions also need tailored guidance.
Interactions And Pairings
Vitamin K works with calcium metabolism and shares pathways with vitamin D. Some products bundle D3 and MK-7 for convenience. If you already take a high-dose D or multivitamin, check total vitamin K to avoid unplanned stacking. For omega-3 users, no direct clash is known, but watch labels for combined formulas so totals remain transparent.
Label Math: Converting, Reading, And Stacking
Many labels list MK-7 per capsule in micrograms. If two capsules show 90 µg each, that’s 180 µg per day at the two-cap serving. If a bottle lists “1 mg,” that equals 1,000 µg—far above common study arms. Some brands add MK-4; that form often appears at milligram-scale doses and short half-life. Keep forms and units straight before you mix products.
Food Versus Capsule: A Practical Take
Food brings more than one nutrient. Natto adds protein and fiber; cheese brings minerals. That said, many shoppers do not eat natto weekly, so a small MK-7 dose can be a simple way to keep intake consistent. Rotate sources across the week.
Evidence, Limits, And Safety Notes
No Tolerable Upper Intake Level exists for vitamin K in healthy adults. The main safety concern is interference with vitamin K antagonist therapy. During pregnancy and lactation, standard AIs for total vitamin K apply; needs vary. Log new supplements with your clinician so medication lists and labs stay aligned.
Trusted Reference Points
You can read the NIH vitamin K fact sheet for adult AIs and drug interactions, and the EFSA guidance on vitamin K for the European AI approach.
Typical MK-7 Doses On Shelves
Marketed capsules cluster at round numbers: 45 µg (often from natto), 90–120 µg (daily singles), 150 µg, and 180 µg (upper end of common study arms). Combo formulas with D3 often sit at 90–120 µg MK-7 per serving. Liquid drops vary and can be easy to titrate.
| MK-7 Label Dose | Who It Often Suits | Notes |
|---|---|---|
| 45–60 µg | Diet rich in greens and some cheese; wants small top-up | Closest to lower trial arms |
| 90–120 µg | Balanced menu with limited fermented foods | Common single-capsule daily range |
| 150–180 µg | Rarely eats natto or aged cheese | Matches upper end of long trials |
Foods That Naturally Provide K2
Natto: Among the richest sources of MK-7, with values near 800–1,000 µg per 100 g in many lab reports. A 50 g pack can deliver hundreds of micrograms.
Aged cheeses: Often contain MK-8 and MK-9; content shifts by style and culture. Hard cheeses tend to carry more than soft styles.
Egg yolks and poultry: Small amounts that add up across the week.
Building A Week That Covers Intake
Pick either: two natto servings across the week, or daily MK-7 at 90–120 µg, or a mix of cheese days plus a modest capsule. Keep intake steady rather than spiky. If you change dose or food pattern and you use warfarin, alert the clinic before labs.
Answering Common Unit Questions
Is 1 Mg Of K2 A Day Typical?
No. One milligram equals 1,000 µg. Human trials often sit at 45–180 µg of MK-7. A 1 mg capsule would far exceed that range.
Is K1 Enough On Its Own?
Total vitamin K targets include both forms. Many people hit the AI with leafy greens alone. Others like a small MK-7 dose because menus change. Intake from food plus capsule counts toward the same daily total.
What About MK-4?
Some products use menatetrenone (MK-4). Labels may show milligram doses because MK-4 has a short half-life. Research programs have tested high amounts of MK-4 many times per day. Read forms and units with care so totals make sense.
MK-7 Versus MK-4: What Sets Them Apart
Both forms activate vitamin K–dependent proteins. MK-7 stays in circulation longer, which makes once-daily dosing practical. MK-4 leaves the bloodstream faster, so trials often split intake into many doses across the day. MK-4 also shows up in animal foods and some fortified items. If your label lists both, totalling micrograms and milligrams across forms keeps your day tidy.
Absorption, Timing, And Storage
Vitamin K is fat-soluble. Take MK-7 with a meal that includes oil, dairy, nuts, or eggs. Pick a time you can repeat. Store bottle away from heat and light. If you miss a day, resume your usual slot the next day rather than stacking doses.
Signals That Your Pattern Needs A Tweak
Scan your grocery basket. If greens, cheese, eggs, or natto rarely make the cut, a small daily MK-7 capsule brings predictability. If your multivitamin already includes vitamin K, you may not need more. Pair capsules with a meal that has some fat.
Sample One-Week Intake Pattern
Here’s a simple plan that keeps intake steady without fuss. Adjust portions to your menu, tastes, and budget.
Week Outline
- Mon: Spinach with oil; 90 µg MK-7 with dinner.
- Tue: Hard cheese with lunch; no capsule.
- Wed: 90 µg MK-7 with breakfast; omelet with greens.
- Thu: Natto bowl at lunch; no capsule.
- Fri: 90 µg MK-7 with dinner; side of broccoli.
- Sat: Cheese board at a party; no capsule.
- Sun: 90 µg MK-7 with a meal; leafy greens at dinner.
This pattern keeps intake smooth. Swap days as life happens. The goal is steady intake, not perfection.
Myths You Can Skip
“More is always better.” Not true. Trial ranges are modest. Pushing doses far above that range adds cost without clear gains.
“You must separate K2 from other vitamins.” No. Many products combine D3 and MK-7. Pairing with a meal helps far more than timing it away from other vitamins.
Bottom Line On Daily K2 Amounts
Agencies list AIs for total vitamin K: 120 µg for adult men and 90 µg for adult women in the U.S., and about 1 µg/kg/day in Europe. No body sets a separate K2 RDA. Human research most often uses MK-7 between 45 and 180 µg per day. That span fits day-to-day life when menus vary. Keep units straight and loop in your care team if you use warfarin.