Why is vitamin K a key nutrient?
There are two naturally occurring forms of this powerful nutrient (vitamin K1, which is found in plants, and vitamin K2, which is produced from vitamin K1 by bacteria in the digestive tract).
Vitamin K3 is a synthetic form of the nutrient, found only in supplements.
Recent research suggests that people who suffer from cancer, bruising, heart disease, menstrual problems, hemorrhagic disease or kidney stones may especially benefit from getting their daily dose
of the nutrient.
Signs and symptoms of a vitamin K deficiency
Vitamin K deficiency is rare because it's so readily available in some vegetables, like leafy greens, but that doesn't mean you shouldn't worry.
Signs and symptoms of a vitamin K deficiency include:
- Poor blood clotting
- Longer bleeding time when you cut yourself
- Bruising easily
- Weak, brittle bones
Who is at risk of a vitamin K deficiency?
Babies: Babies are born with sterile intestines, which makes it harder for them to absorb and produce vitamin K in their digestive tracts.
People with digestive issues: People who can't absorb fats (for example, those suffering from obstructive jaundice, celiac disease, diarrhea, etc.) will have a harder time
absorbing this fat-soluble nutrient.
Medication users: Certain medications (for example, those used to treat heart disease) block the body's absorption powers of vitamin K.
People taking supplements: Research shows vitamins A and E interfere with the body's ability to absorb vitamin K.
Recommended daily allowance for vitamin K
The Recommended Dietary Allowance (RDA) for vitamin K is:
Infants (0 to 6 months): 2 micrograms (mcg) per day
Infants (7 to 11 months): 2.5 mcg per day
Children (ages 1 to 3): 30 mcg per day
Children (ages 4 to 8): 55 mg per day
Children (ages 9 to 13): 60 mcg per day
Teenagers (ages 14 and 18): 75 mcg per day
Males (ages 19 and older): 120 mcg per day
Females (ages 19 and older): 90 mcg per day
Pregnant women: 90 mcg per day
Lactating women: 90 mg per day
Food sources of vitamin K
Kale, boiled, 1 cup = 1062.10 mcg
Spinach, boiled, 1 cup = 888.48 mcg
Brussels sprouts, boiled, 1 cup = 218.80 mcg
Parsley, fresh, 2 tablespoons = 123 mcg
Avocado, slices, 1 cup = 29.20 mcg
Pumpkin seeds, raw, 1/4 cup = 17.73 mcg
Tips for getting more vitamin K in your diet
1. Don't scrimp on fat. Vitamin K is a fat-soluble nutrient, meaning it needs dietary fat (like that from oils) to readily absorb into the body.
2. Be mindful about cooking certain foods. Overcooking foods high in vitamin K decreases the digestible amount of the nutrient by almost 20 percent.
3. Eat unprocessed foods. Even though vitamin K is more resilient to processing than other vitamins, unprocessed foods contain higher amounts of the nutrient than processed ones.
Vitamin K-rich recipes