Vitamin K


Nutrient Library: Vitamin K

Vitamin K:

  • What does it do?
  • How much do you need?
  • What are the best food sources?
  • What happens if you don't get enough?
  • What happens if you get too much?

What does it do?
Vitamin K is a fat-soluble vitamin that plays an important role in blood clotting. In fact, without it our blood would not clot. Its name is derived from the German word "koagulation." Vitamin K also contributes to skeletal health because it plays a role in bone mineralization. Like vitamin D, vitamin K is one that your body can produce on its own, but usually not in quantities that meet the body's needs. Bacteria of the lower bowel produce vitamin K and then store it in the liver. However, it has been difficult to determine the contribution of this form of vitamin K to body stores.

How much do you need?
The following table lists the recommended intake for healthy people based on current scientific information.

Life Stage Group Recommended Dietary Allowance/Adequate Intake
(see note below)
Tolerable Upper Intake Level (UL)
0-6 mo.
7-12 mo.
Not determinable due to lack of data on adverse effects and concern about inability to handle excess amounts. Source should be from food only to prevent high levels of intake.
1-3 yr.
4-8 yr.
9-13 yr.
14-18 yr.
19-30 yr.
31-50 yr.
51-70 yr.
> 70 yr.
9-13 yr.
14-18 yr.
19-30 yr.
31-50 yr.
51-70 yr.
> 70 yr.
< 18 yr.
19-30 yr.
31-50 yr.
< 18 yr.
19-30 yr.
31-50 yr.

NOTE: The table is adapted from the Dietary Reference Intakes reports. Recommended Dietary Allowances (RDAs), when available, are in bold type; Adequate Intakes (AIs) are followed by an asterisk(*). RDAs and AIs may both be used as goals for individual intake. RDAs are set to meet the needs of almost all individuals (97 to 98 percent) in a group. For healthy breastfed infants, the AI is the mean intake. The AI for other life stage and gender groups is believed to cover the needs of all individuals in the group, but lack of data means the percentage of individuals covered by this intake cannot be specified with confidence.

UL = The maximum level of daily nutrient intake that is likely to pose no risk of adverse effects. Unless otherwise specified, the UL represents total intake from food, water and supplements.

What are the best food sources?
The best food sources of vitamin K are leafy green vegetables like spinach, broccoli, eggs, wheat bran, and olive, soy and canola oils. Because vitamin K is a fat-soluble vitamin, its absorption from vegetables is enhanced by the presence of dietary fat: so sauté your spinach in a little olive oil.

See healthy recipe collections from EatingWell

What happens if you don't get enough?
Vitamin K deficiency is extremely rare in healthy adults. Cases of deficiency usually only occur in individuals with malabsorption problems, severe liver damage or disease, or those being treated with drugs that interfere with the vitamin's metabolism. Your health care professional will let you know if you fall into one of these categories. The main symptoms in these cases are that blood doesn't coagulate normally and you can experience increased bruising.

Infants born in the United States and Canada routinely receive a dose of vitamin K at birth (usually 0.5-1 mg intramuscularly or 2.0 mg orally within 6 hours of birth). This is because infants are usually born with poor vitamin K status and low amounts of clotting factors, thus increasing the risk of bleeding during the first few weeks. In addition, their immature intestines cannot produce vitamin K. Exclusively breastfed infants receive low amounts of vitamin K from human milk.

What happens if you get too much?
It's not likely that you will experience adverse effects from consuming too much vitamin K-but moderation is still the best approach. However, individuals on warfarin therapy-an anticoagulant, or blood-thinning drug-are advised to monitor intake closely and they need to maintain steady vitamin K intake levels. Vitamin K may reduce the effectiveness of this drug. These individuals should maintain their normal dietary and supplementation patterns once an effective dose of the drug has been established. It is generally recommended that these individuals try to consume the recommended intake but avoid large fluctuations in intake.


Singapore Chile Crab with Spinach
Restaurants all over Singapore have chile crab on their menus-it's one of the national dishes. Usually made with whole crabs swimming in a spicy chile sauce, this streamlined version is much simpler-and less messy to eat. Although a little more expensive, this dish looks the most beautiful and tastes the best when made with "colossal" lump crabmeat. Make it a meal: Serve over instant brown rice. Cool off with mango sorbet for dessert.

Makes 4 servings, 1 cup each

ACTIVE TIME: 30 minutes
TOTAL TIME: 30 minutes

1/2 cup water
1/4 cup ketchup
1 tablespoon reduced-sodium soy sauce
1 tablespoon tomato paste
1 teaspoon cornstarch
1 tablespoon toasted sesame oil
1/4 cup minced shallot
2 tablespoons minced garlic
2 tablespoons minced red chile, or to taste
1 1/2 tablespoons minced fresh ginger
1 6-ounce bag baby spinach
1 pound pasteurized crabmeat, drained if necessary

  1. Whisk water, ketchup, soy sauce, tomato paste and cornstarch in a medium bowl.
  2. Heat oil in a large skillet over medium-high heat. Add shallot and cook, stirring occasionally, until softened, about 1 minute. Add garlic, chile and ginger and cook, stirring, until fragrant, about 30 seconds. Add spinach and stir until just wilted, 1 to 2 minutes. Stir in the sauce and crab; reduce heat to medium-low, cover and cook, stirring occasionally, until heated through, about 2 minutes.

NUTRITION INFORMATION: Per serving: 187 calories; 5 g fat (1 g sat, 2 g mono); 132 mg cholesterol; 11 g carbohydrate; 25 g protein; 1 g fiber; 785 mg sodium; 360 mg potassium.

Nutrition bonus: Vitamin A (90% daily value), Iron & Vitamin C (40% dv), Folate (22% dv), Calcium (15% dv). 1 Carbohydrate Serving. Exchanges: 1 vegetable, 3 very lean meat, 1 fat

More Healthy Seafood Recipes and Cooking Tips

Chicken & Asparagus with Melted Gruyere
This sauce does double duty, delivering tons of flavor and healthy asparagus at the same time. Make it a meal: Serve alongside brown rice and a green salad.

Makes 4 servings

ACTIVE TIME: 35 minutes
TOTAL TIME: 35 minutes

8 ounces asparagus, trimmed and cut into 1-inch pieces
2/3 cup reduced-sodium chicken broth
2 teaspoons plus 1/4 cup all-purpose flour, divided
4 boneless, skinless chicken breasts (1-1 1/4 pounds), trimmed
1/4 teaspoon salt
1/2 teaspoon freshly ground pepper
1 tablespoon canola oil
1 shallot, thinly sliced
1/2 cup white wine
1/3 cup reduced-fat sour cream
1 tablespoon chopped fresh tarragon
2 teaspoons lemon juice
2/3 cup shredded Gruyère cheese

  1. Place a steamer basket in a large saucepan, add 1 inch of water and bring to a boil. Add asparagus; cover and steam for 3 minutes. Uncover, remove from the heat and set aside.
  2. Whisk broth and 2 teaspoons flour in a small bowl until smooth. Set aside.
  3. Place the remaining 1/4 cup flour in a shallow dish. Sprinkle chicken with salt and pepper and dredge both sides in the flour, shaking off any excess.
  4. Heat oil in a large skillet over medium heat. Add the chicken and cook until golden brown, 3 to 4 minutes per side, adjusting heat as needed to prevent scorching. Transfer to a plate and cover to keep warm.
  5. Add shallot, wine and the reserved broth mixture to the pan; cook over medium heat, stirring, until thickened, about 2 minutes. Reduce heat to medium-low; stir in sour cream, tarragon, lemon juice and the reserved asparagus until combined. Return the chicken to the pan and turn to coat with the sauce. Sprinkle cheese on top of each piece of chicken, cover and continue cooking until the cheese is melted, about 2 minutes.

NUTRITION INFORMATION: Per serving: 306 calories; 15 g fat (6 g sat, 5 g mono); 91 mg cholesterol; 7 g carbohydrate; 31 g protein; 1 g fiber; 298 mg sodium; 343 mg potassium.

Nutrition bonus: Selenium (36% daily value), Calcium (25% dv), good source of omega-3s. 1/2 Carbohydrate Serving. Exchanges: 1/2 starch, 4 lean meat, 1/2 fat

More Healthy Chicken Recipes

Mini Meatloaves
Traditional meatloaf is made with ground beef, pork and veal; here we replace the veal with ground turkey for a tender, flavorful and leaner version of the classic. Baking individual portions in muffin tins speeds cooking, standardizes serving size and produces a moist, delicious main dish.

Makes 8 servings

ACTIVE TIME: 10 minutes
TOTAL TIME: 40 minutes

8 ounces lean ground beef
8 ounces lean ground pork
8 ounces ground turkey breast
1 large egg, lightly beaten
1/4 cup quick-cooking oats
1/4 cup chopped fresh parsley
1/4 cup ketchup, divided
3 tablespoons low-fat milk
1 small onion, chopped (3/4 cup)
3/4 teaspoon salt
1/8 teaspoon freshly ground pepper
1 1/2 teaspoons Worcestershire sauce

  1. Preheat oven to 375°F. Coat 8 muffin cups with cooking spray.
  2. Mix beef, pork, turkey, egg, oats, parsley, 2 tablespoons ketchup, milk, onion, salt and pepper in a large bowl.
  3. Form the mixture into 8 balls and place in the prepared muffin cups. Combine the remaining 2 tablespoons ketchup and Worcestershire sauce and spread about 1/2 teaspoon over each mini meatloaf.
  4. Place the muffin pan on a baking sheet. Bake the meatloaves until their internal temperature reaches 160°F, 25 to 30 minutes. Pour off fat before serving.

NUTRITION INFORMATION: Per serving: 184 calories; 10 g fat (3 g sat, 4 g mono); 78 mg cholesterol; 5 g carbohydrate; 18 g protein; 1 g fiber; 387 mg sodium; 317 mg potassium. Nutrition bonus: Vitamin K (39% daily value), Potassium (16% dv). 0 Carbohydrate Servings

TIP: Baking individual portions of meatoaf in muffin tins speeds cooking, standardizes serving size and produces a moist, delicious main dish.

Healthy Recipe Collections

From with permission. © 2008 Eating Well Inc.

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