Menaquinone-4 and menaquinone-7 absorption in healthy women
What it found
In healthy women, a single dose of menaquinone-7 was absorbed and showed up in the blood, while menaquinone-4 was not detected at any time point.
Taking menaquinone-7 for a week raised blood levels in all the women, but taking menaquinone-4 did not.
What they found
Studies in people
Single dose absorption
After a single 420 microgram dose, menaquinone-7 was well absorbed and reached its highest blood level at 6 hours. It was still detectable 48 hours after intake. Menaquinone-4 was not detectable in the blood of any woman at any time point.
One week of daily doses
Taking 60 micrograms of menaquinone-7 daily for 7 days significantly raised blood menaquinone-7 levels in all the women. Taking 60 micrograms of menaquinone-4 daily did not raise blood menaquinone-4 levels.
Amount needed
The authors say that menaquinone-4 intake of greater than 420 to 500 micrograms is required, based on their data and earlier work.
Studies in people and animals
Conversion in the body
The authors note that all vitamin K forms can be converted to menaquinone-4 in the body. In a previous rat study from their group, a nutritional dose of menaquinone-4 did not raise menaquinone-4 levels in tissues outside the liver, while menaquinone-7 did.
What the authors conclude
“We conclude that MK-4 present in food does not contribute to the vitamin K status as measured by serum vitamin K levels.”
Also in their conclusions
- They conclude that menaquinone-4 present in food does not contribute to the vitamin K status as measured by serum vitamin K levels.
- They say that menaquinone-7 significantly increases serum menaquinone-7 levels and therefore may be of particular importance for extrahepatic tissues.
- They advise that the nutritional values of vitamin K2 homologues should be differentiated with regard to bioavailability and efficacy.
How it was done
The authors say that little was known about how well nutritional doses of menaquinone-4 are taken in and used by the body. They wanted to compare how menaquinone-4 and menaquinone-7 are absorbed.
Ten healthy Japanese women aged 20 to 21 took part in two studies. In the first, they took a single 420 microgram dose of either menaquinone-4 or menaquinone-7 with breakfast, and blood was taken over 72 hours. In the second, they took 60 micrograms of either form daily after supper for one week.
What it can’t tell you
- This was a small study in 10 healthy young women, so the results may not apply to other groups such as men, older people or those with health conditions.
- The study measured blood levels of menaquinone-4 and menaquinone-7, not health outcomes like bone strength or heart health.
Who paid
- Authors work at
- Fine Chemical Laboratory, Japan
The paper
- Title
- Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women
- Type
- Randomised controlled trial
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Sato T, Schurgers LJ, Uenishi K (2012). Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. Nutrition journal. doi:10.1186/1475-2891-11-93Free full textPubMed 23140417DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error