Vitamin K1, also called phylloquinone, is found in plant foods such as raw vegetables. It makes up about 75-90% of all K vitamins consumed by humans.
Foods With Vitamin K1
Vitamin K1 is produced by plants. It is an excellent source of vitamin K in the human diet.
The following list includes several foods that are high in vitamin K1.
Each amount represents the amount of vitamin K1 in one cup of cooked vegetables,
- Kale: 1,062 mcg
- Collard greens: 1,059 mcg
- Spinach: 889 mcg
- Turnip greens: 529 mcg
- Broccoli: 220 mcg
- Brussels sprouts: 218 mcg
Health Benefits of Vitamin K1
Research into the health benefits of vitamin K has suggested that it can be beneficial for blood clotting, bone health, and cardiovascular health.
Vitamin K and blood clotting
Many of the proteins involved in blood clotting rely on vitamin K for their function. Blood clotting may sound bad, and sometimes it is. Without it, however, you may bleed excessively and end up dying from minor injuries.
Some people have problems with blood clotting and are taking a drug called warfarin to prevent the blood from clotting easily. If you are taking this medication, you should keep your vitamin K consistent due to its powerful effects on blood clotting.
Although much of this attention is focused on dietary sources of vitamin K1, it may also be important to monitor vitamin K2 intake.
Some studies have shown that a single natto supplement rich in vitamin K2 alters blood clotting patterns for up to four days. This was a much greater effect than vitamin K-rich foods. Therefore, it is probably a good idea to monitor a diet rich in vitamin K1 and vitamin K2 if you are on anemia.
Vitamin K and bone health
Many experts believe that vitamin K activates the proteins needed for bone growth and development. Many observational studies have linked low levels of vitamin K1 and K2 with a high risk of fractures, although these studies are incorrect in showing cause and effect as controlled studies.
Many controlled studies examining the effects of vitamin K1 supplements on bone loss were inconsistent and showed little benefit.
However, one review of controlled studies concluded that the addition of vitamin K2 such as MK-4 significantly reduced the risk of fractures. However, since this review, several large controlled studies have shown no effect.
Overall, the available studies were inconsistent, but the available evidence was convincing enough that the European Food Safety Authority concluded that vitamin K is directly involved in normal bone health.
Advanced, controlled studies are needed to further investigate the effects of both vitamin K1 and K2 on bone health and to determine if there is a real difference between the two.
Vitamin K and heart health
In addition to blood pressure and bone health, vitamin K also appears to play an important role in preventing heart disease. Vitamin K activates a protein that helps prevent calcium from building up in your arteries. These calcium deposits contribute to the formation of plaque, so it is not surprising that they are a strong predictor of heart disease.
Numerous studies have suggested that vitamin K2 is better than K1 in lowering these calcium levels and reducing the risk of heart disease.
However, high-quality controlled studies have shown that both vitamin K1 and vitamin K2 supplement and improve various forms of heart health.
However, more studies are needed to prove that vitamin K supplementation actually causes this improvement in heart health. Besides, further research is needed to determine whether K2 is actually better at cardiovascular health than K1.
What is vitamin K1 good for?
Vitamin K1 is generally the preferred form of vitamin K because it is less toxic and works faster for certain conditions. Vitamin K is most commonly used for blood clotting problems or for reversing the blood-thinning effects of warfarin.
Is vitamin K1 safe?
Most people get enough vitamin K from their diets. There have been no adverse effects of vitamin K seen with the levels found in food or supplements. However, this does not rule out the danger with high doses. Researchers have not set a maximum safe dose.