Vitamin K2 and its effects on bones, blood vessels, and other health areas
What it found
Vitamin K2 helped direct calcium into bones instead of blood vessels in studies of people, animals, and cells.
It was also linked to better bone density and lower heart disease risk.
What they found
Studies in people
Bone density in women
A trial of 219 women after menopause found that 100 µg of vitamin K2 daily for one year raised overall bone density. Another trial of 244 women took 180 mcg of MK-7 daily for three years and saw less bone loss and fewer spine fractures. A combined analysis of 6,759 women also linked vitamin K2 to stronger bones and fewer breaks.
Liver cancer recurrence
In a trial of patients with hepatitis C and liver cancer, those taking 45 mg of vitamin K2 daily had fewer cancer returns over three years. Their return-free rates were 38.8% compared to 9.9% in the control group. Overall survival did not differ between the groups.
Blood sugar control
In the Framingham Offspring study, taking vitamin K1 for 12 months improved how the body handled sugar. Another report found vitamin K1 lowered fasting blood sugar and insulin resistance in men but not in women. Vitamin K2 may need a smaller amount than K1 to work.
Animal and lab studies
Brain protection in cells
Lab studies show vitamin K helps make fats needed for brain cell membranes. It also activates a protein that stops brain cells from dying. Low vitamin K levels were linked to a protein tied to Alzheimer's disease.
Studies in people and animals
Calcium in blood vessels
In the Rotterdam Cohort, taking 25 µg of vitamin K2 daily lowered the risk of vessel hardening by 52% and heart death by 57%. Lab tests on rat cells showed a form called MK-4 slowed calcium buildup in vessel walls.
Other findings
Getting enough vitamin K2
Vitamin K1 comes from leafy greens, while K2 is mostly in fermented foods like natto and small amounts in meat and dairy. Because Western diets have little K2, the authors suggest supplements of 180 to 360 µg daily for heart health. The World Health Organization has not set an upper limit for intake.
What the authors conclude
- They say vitamin K2 helps move calcium into bones and out of blood vessels, which may prevent osteoporosis and heart problems.
- They recommend getting enough vitamin K2 through food and supplements, especially for women after menopause.
- They note that no side effects from high vitamin K intake have been reported.
How it was done
The authors wanted to gather what is known about vitamin K2 because it is hard to get enough from Western diets. They focused on how it moves calcium around the body, especially for women after menopause.
They gathered and summarized existing research on vitamin K forms and their roles in the body. The sources included trials in people, animal experiments, and cell studies. They looked at effects on blood vessels, bones, the brain, the liver, infections, joints, blood sugar, and teeth.
What it can’t tell you
- This is a summary of many different studies, so it cannot prove that vitamin K2 alone caused every benefit seen.
- Some findings come from animals or cells and might not happen the same way in people.
- Studies that follow people over time can show links but cannot prove cause and effect.
Who paid
- Funding
- Funded by Soonchunhyang University (from the PubMed record).
- Conflicts
- No potential conflict of interest relevant to this article was reported.
- Authors work at
- Soonchunhyang University Bucheon Hospital, Korea
The paper
- Title
- Vitamin K: Calcium Metabolism Modulator for Menopausal Women
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Kim TH, Kim H, Lee HH, Sang JH (2024). Vitamin K: Calcium Metabolism Modulator for Menopausal Women. Journal of menopausal medicine. doi:10.6118/jmm.24023Free full textPubMed 39829192DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error