Vitamin K helps your body by making proteins for healthy bones and tissues. It also makes proteins for blood clotting. If you don’t have enough vitamin K, you may bleed too much.
Vitamin K is known as the clotting vitamin, because without it blood would not clot. Some studies suggest that it helps maintain strong bones in the elderly.
Newborns have very little vitamin K. They usually get a shot of vitamin K soon after they are born.
If you take blood thinners, you need to be careful about how much vitamin K you get. You also need to be careful about taking vitamin E supplements. Vitamin E can interfere with how vitamin K works in your body. Ask your health care provider for recommendations about these vitamins.
There are different types of vitamin K. Most people get vitamin K from plants such as green vegetables, and dark berries. Bacteria in your intestines also produce small amounts of another type of vitamin K.
The best way to get the daily requirement of vitamin K is by eating food sources. Vitamin K is found in the following foods:
- Green leafy vegetables, such as kale, spinach, turnip greens, collards, Swiss chard, mustard greens, parsley, romaine, and green leaf lettuce
- Vegetables such as Brussels sprouts, broccoli, cauliflower, and cabbage
- Fish, liver, meat, eggs, and cereals (contain smaller amounts)
Vitamin K is also made by the bacteria in the lower intestinal tract.
Vitamin K deficiency is very rare. It occurs when the body can’t properly absorb the vitamin from the intestinal tract. Vitamin K deficiency can also occur after long-term treatment with antibiotics.
People with vitamin K deficiency are often more likely to have bruising and bleeding.
If you take blood thinning drugs (such as anticoagulant/antiplatelet drugs), you may need to limit vitamin K foods. You may also need to eat a consistent amount of vitamin K containing foods on a day to day basis if you consume these foods. You should know that vitamin K or foods containing vitamin K can affect how these drugs work.
It is important for you to keep vitamin K levels in your blood about the same from day to day. Ask your health care provider how much vitamin K-containing foods you should eat.
The Recommended Dietary Allowance (RDA) for vitamins reflects how much of each vitamin most people should get each day.
- The RDA for vitamins may be used as goals for each person.
- How much of each vitamin you need depends on your age and gender.
- Other factors, such as pregnancy, breast-feeding, and illness may increase the amount you need.
The Food and Nutrition Board at the Institute of Medicine Recommended Intakes for Individuals – Adequate Intakes (AIs) for vitamin K:
- 0 to 6 months: 2.0 micrograms per day (mcg/day)
- 7 to 12 months: 2.5 mcg/day
- 1 to 3 years: 30 mcg/day
- 4 to 8 years: 55 mcg/day
- 9 to 13 years: 60 mcg/day
Adolescents and Adults
- Males and females age 14 to 18: 75 mcg/day
- Males and females age 19 and older: 90 mcg/day for females (including those who are pregnant and lactating) and 120 mcg/day for males