Vitamin K helps with blood clotting and bone building
Vitamin K helps your body make proteins that are needed for blood clotting and the building of healthy bones.
- Preventing hemorrhagic disease in newborns: Vitamin K shots can help prevent bleeding problems in newborns with low levels of vitamin K.
- Treating and preventing bleeding problems in people with low levels of prothrombin (blood-clotting protein): Low prothrombin levels may be caused by certain medications. People with low levels of this protein may benefit from taking vitamin K orally or intravenously.
- Preventing bleeding problems in people with vitamin K-dependent clotting factors deficiency (VKCFD): VKCFD is an inherited bleeding disorder. Taking vitamin K by mouth or through an injection can help prevent bleeding in people with VKCFD.
- Reversing the effects of excess warfarin: Warfarin is a type of blood-thinning medication used to prevent blood clotting. Taking vitamin K can reverse the effects of too much warfarin, and can also be used along with warfarin to stabilize blood clotting time.
- Osteoporosis: Osteoporosis makes the bones weak and vulnerable to fractures. A specific form of vitamin K2 may be helpful in improving bone strength and reducing fracture risk.
Potential other uses
While vitamin K may be effective for other conditions, there isn’t enough evidence to support these uses. Such uses include:
What are the different forms of vitamin K?
Vitamin K is a type of fat-soluble vitamin that comes in two main forms:
- Phylloquinone (also called vitamin K1): Found in green leafy vegetables such as kale, collard greens and spinach.
- Menaquinone (also called vitamin K2): Found in some animal foods such as meat, eggs and cheese and in fermented foods. Vitamin K2 can also be formed by bacteria in the human gut.
A synthetic substance called menadione (also called vitamin K3) has vitamin K-like benefits and is used in some countries as a nutritional supplement. However, over-the-counter supplements of menadione are currently banned by the U.S. FDA because they are potentially toxic for humans.
Are there any risks to taking vitamin K?
Vitamin K is widely found throughout the body including the liver, heart, brain, bones and pancreas. Unlike other fat-soluble vitamins, vitamin K rarely accumulates to toxic levels in the body even if taken in excess amounts. This is because it is broken down quickly and eliminated through urine or stool.
You should consult with your doctor before taking vitamin K supplements, especially if you:
If you are on blood thinners, particularly warfarin, you should not take vitamin K. Children should also not be given vitamin K unless advised by a doctor.
Medically Reviewed on 5/6/2021