Why this study matters

As we get older, calcium can gradually accumulate in the arteries, making them stiffer and less able to adapt to changes in blood flow. This process—called vascular calcification—is strongly linked to heart disease, stroke, and overall cardiovascular aging.

A 2023 systematic review and meta-analysis published in Frontiers in Nutrition examined whether vitamin K supplementation could help slow this process. The analysis included 14 randomized controlled trials with more than 1,500 participants, making it one of the most comprehensive evaluations to date.

What the researchers found

Across the included trials, vitamin K supplementation—both K1 and K2—was associated with:

• Slower progression of coronary artery calcification (CAC)
• Significant reductions in dp‑ucMGP, a biomarker of poor vitamin K status and vascular calcification
• No increase in adverse events

The reduction in dp‑ucMGP is especially important. This biomarker reflects the amount of inactive matrix Gla protein (MGP), a molecule that helps prevent calcium from depositing in arteries. When vitamin K levels are low, MGP cannot function properly. Supplementation appears to restore this protective mechanism.

Why vitamin K matters for arterial health

Vitamin K plays a central role in activating proteins that regulate where calcium ends up in the body. In simple terms:

Vitamin K helps keep calcium in the bones and out of the arteries.

This makes it a uniquely interesting nutrient for older adults, especially those focused on heart health, bone strength, and healthy aging.

What this means for older adults

This study does not prove that vitamin K prevents heart disease, but it does provide strong evidence that it may help slow the progression of arterial calcification, particularly in the coronary arteries.

The findings also reinforce the importance of maintaining good vitamin K status through diet—and, when appropriate, through supplements discussed with a clinician.

How to support healthy vitamin K levels

1. Eat vitamin K–rich foods

Vitamin K1 is abundant in leafy greens, while vitamin K2 (including MK‑7) is found in certain fermented foods. Examples include:

• Spinach
• Kale
• Swiss chard
• Broccoli
• Natto (richest natural source of MK‑7)
• Fermented cheeses

2. Understand the difference between K1 and K2

K1 supports blood clotting and general vitamin K status. K2—especially the MK‑7 form—has a longer half-life and may be more effective at activating MGP, the protein that helps keep arteries flexible.

3. Consider supplements only with guidance

Vitamin K supplements are generally well tolerated, but older adults taking blood thinners or multiple medications should always consult a clinician before adding any form of vitamin K.

What this study does not show

• It does not prove vitamin K prevents heart attacks or strokes.
• It does not identify an optimal dose for vascular health.
• It does not replace lifestyle habits like movement, diet, and blood pressure control.

Key takeaways

• Vitamin K supplementation may help slow vascular calcification, especially in the coronary arteries.
• dp‑ucMGP, a marker of poor vitamin K status, improves significantly with supplementation.
• Vitamin K2 (MK‑7) may offer unique advantages due to its longer half-life.
• Leafy greens and fermented foods remain excellent dietary sources.

Reference

The study is available here: Vitamin K supplementation and vascular calcification: a systematic review and meta-analysis of randomized controlled trials

A quick note on oxalates and kidney comfort

While vitamin K helps guide calcium toward the bones and away from the arteries, it’s also worth remembering that high‑oxalate foods can push calcium in the opposite direction—toward the kidneys. Foods like spinach, beet powder, nuts, and certain berries are nutritious, but in large amounts they may contribute to microscopic crystal formation that stresses the kidneys over time. Staying well hydrated, pairing oxalate‑rich foods with calcium, and keeping intake moderate can help support kidney comfort while still enjoying a varied, nutrient‑rich diet.