From the Guidelines
Vitamin K may help mitigate the potential arterial damage caused by vitamin D supplementation, but the current evidence is not strong enough to support a definitive conclusion. The most recent study on this topic, published in 2025 in the journal Kidney International 1, suggests that vitamin K compounds, such as vitamin K1 and MK-7, may decrease serum dephosphorylated uncarboxylated matrix Gla protein levels, but the effect on calcification progression in patients with advanced chronic kidney disease (CKD) is inconsistent. Some key points to consider include:
- The VitaVasK pilot trial demonstrated significant reductions of thoracic aorta calcification progression in association with significant decreases in dephosphorylated uncarboxylated matrix Gla protein serum levels over 18 months when vitamin K1 was supplemented during hemodialysis sessions 1.
- However, the difference in coronary artery calcification did not reach the level of statistical significance, likely due to recruitment difficulties, high dropout rate, and small sample size 1.
- Vitamin K activates matrix Gla protein, which inhibits calcium deposition in blood vessels, potentially reducing the risk of arterial calcification.
- If you're taking vitamin D supplements, especially at higher doses (above 2,000 IU daily), it may be prudent to ensure adequate vitamin K intake, typically through dietary sources or supplements containing vitamin K2 (90-180 mcg daily) or vitamin K1 from leafy green vegetables. It's essential to consult with a healthcare provider before taking vitamin K supplements, especially for individuals taking blood thinners like warfarin, as vitamin K can interfere with these medications.
From the Research
Vitamin K and Arterial Damage Prevention
- The current evidence on the role of vitamin K in preventing arterial damage caused by vitamin D is limited and inconclusive 2, 3.
- Some studies suggest that vitamin K2 supplementation may have a protective effect on coronary artery calcification, particularly in individuals with high cardiovascular risk 4, 5.
- A systematic review of controlled trials found that vitamin K supplementation does not consistently prevent progression of calcification, atherosclerosis, or arterial stiffness, although there may be some benefit in people with calcification at study entry 3.
- A study on nondialyzed patients with chronic kidney disease stages 3-5 found that vitamin K2 supplementation reduced the progression of atherosclerosis, but did not significantly affect the progression of calcification 6.
Interaction between Vitamin K and Vitamin D
- Some studies have investigated the combined effects of vitamin K and vitamin D supplementation on cardiovascular health 2, 4, 5, 6.
- The evidence suggests that the combination of vitamin K and vitamin D may have synergistic effects on cardiovascular health, although the exact mechanisms are not fully understood 2, 6.
- Further research is needed to determine the optimal dosages and durations of vitamin K and vitamin D supplementation for preventing arterial damage and promoting cardiovascular health 4, 5, 3.