Vitamin K2 (MK‑7) Lowers Calcification Risk in Dialysis Patients

Vitamin K2 (MK‑7) Lowers Calcification Risk in Dialysis Patients

Quick Summary:
A short‑term study gave high‑dose vitamin K2 (menaquinone‑7, MK‑7) to people on chronic haemodialysis. The supplement cut a blood marker linked to artery hardening by up to 46 % – the higher the dose, the bigger the drop. Vitamin K1 (phylloquinone) intake didn’t affect this marker.

What The Research Found

• MK‑7 reduced the inactive form of MGP – a protein that protects blood vessels from calcium buildup.
• The reduction was dose‑dependent:
• 360 µg three times a week → 17 % drop
• 720 µg three times a week → 33 % drop
• 1,080 µg three times a week → 46 % drop
• People who ate more vitamin K2 from food already had lower levels of the “inactive” MGP marker.
• Vitamin K1 (the K‑type found in leafy greens) did not influence the marker.
• Some participants stopped early because the tablets smelled bad and caused mild stomach upset.

Study Details

• Who was studied: 200 adults receiving regular haemodialysis (a kidney‑replacement therapy).
• How long: 8 weeks (about two months).
• What they took: MK‑7 capsules, given three times a week at one of three doses – 360 µg, 720 µg, or 1,080 µg.
• How the effect was measured: Blood levels of “desphosphorylated‑uncarboxylated‑MGP” (dp‑uc‑MGP), a lab test that signals how well the body can stop calcium from depositing in arteries.

What This Means For You

• If you are on haemodialysis: High‑dose vitamin K2 might help keep your blood vessels softer and less prone to calcification, but the right dose isn’t settled yet.
• If you eat a lot of leafy greens (vitamin K1): This study suggests K1 alone may not protect against this specific calcification marker in dialysis patients.
• If you consider a supplement: Look for MK‑7 (not K1) and be aware that large doses can have an unpleasant smell or mild stomach upset. Talk to your kidney doctor before starting any new vitamin regimen.
• For the general public: Maintaining a balanced diet that includes both K1 (green veggies) and K2 (fermented foods like natto, cheese, and some meats) is still a good heart‑healthy habit, even though K2 showed the stronger effect in this patient group.

Study Limitations

• Short follow‑up: Only 8 weeks, so we don’t know if the benefits last or if any long‑term side effects appear.
• Surrogate marker only: The study measured a blood test, not actual hardening of arteries or heart events.
• Drop‑outs due to taste/smell: The unpleasant odor of the tablets may limit real‑world use.
• No comparison to a placebo: All participants received some dose of MK‑7, so we can’t tell how much of the change was due to the supplement versus other factors.
• Specific to dialysis patients: Results may not apply to people with normal kidney function.

Always discuss new supplements with your healthcare provider, especially if you have kidney disease or are on dialysis.