Key takeaways
- K1 comes from leafy greens.
- K2 comes from fermented foods.
- Activates calcium-binding proteins.
- Pairs naturally with vitamin D.
- Interacts with warfarin.
Vitamin D gets the spotlight for calcium, but vitamin K quietly decides where that calcium ends up.
Vitamin K1 vs K2
| Vitamin K1 | Vitamin K2 | |
|---|---|---|
| Name | Phylloquinone | Menaquinones (MK-4, MK-7) |
| Main sources | Kale, spinach, broccoli | Natto, cheese, egg yolks |
| Main role | Blood clotting | Calcium in bones and vessels |
How vitamin K manages calcium
Osteocalcin
Activated by vitamin K, it helps bind calcium into bone.
Matrix Gla protein
Helps keep calcium from building up in soft tissues.
The vitamin D partnership
Vitamin D brings calcium in; vitamin K helps put it in the right place.
Getting enough
- Leafy greens: kale, spinach, collards
- Broccoli and Brussels sprouts
- Fermented foods such as natto
- Cheese and egg yolks
VertiFree includes vitamin K with vitamin D to support healthy calcium regulation, alongside ligustrum, Sophora japonica and 15 herbs.
Important: vitamin K can reduce the effect of warfarin (Coumadin). If you take warfarin or another blood thinner, do not start any vitamin K supplement, including VertiFree, without your doctor's approval.
Sources
- NIH Office of Dietary Supplements – "Vitamin K" fact sheet.
- Beulens J.W. et al. – "The role of menaquinones (vitamin K2) in human health," British Journal of Nutrition, 2013.
- Linus Pauling Institute, Oregon State University – "Vitamin K."
Common questions
What does vitamin K do for calcium?
It activates proteins that bind calcium into bone and keep it out of soft tissues.
What is the difference between K1 and K2?
K1 comes from leafy greens; K2 comes from fermented and animal foods.
Can I take vitamin K with warfarin?
Only with your doctor's approval, as it can reduce warfarin's effect.