|
 |
|
|
|
Essential for blood clotting
Without enough vitamin K in your blood, a small skin cut could become a major bleeder. Fortunately, most of us have plenty of this essential vitamin to make our blood clot properly. In fact, K was taken from the Danish word "koagulation" which, of course, means coagulation.
Vitamin K is a fat-soluble vitamin. Besides preventing abnormal bleeding, it helps calcium form bones.
About half of your intake of vitamin K comes from what you eat in vegetables like raw cauliflower and spinach; the other half is produced by naturally occurring bacteria in your intestines. Because of this, you're unlikely to be deficient.
Quick Facts About Vitamin K
- RDA is 65 to 80 micrograms (mcg) per day for healthy adults.
- Some foods rich in vitamin K are green leafy vegetables (broccoli, Brussels sprouts, cabbage, cauliflower, spinach, and turnip greens), milk, fish liver oil, green tea, and soybean oil.
- Some signs of vitamin K deficiency are easy bruising, impaired blood clotting, and frequent nosebleeds.
|
|
|
|
|
You May Need More Vitamin K if You Have (or Have Had)
- Chronic malnutrition
- Impaired fat absorption
- Intestinal damage
- Recent injury or severe burns
- Recent surgery
- Crohn's disease or ulcerative colitis
- Liver impairment
Or if You're
- Over age 55
- Under excessive stress
- A premature newborn
- Taking antibiotics that may inhibit the function of vitamin K-producing bacteria in your intestines
- Taking medications that inhibit fat absorption
- Suffering from cystic fibrosis because of fat absorption problems
What Works Best -- and Worst -- with Vitamin K
- Vitamin K deficiency may cause vitamin E to inhibit your blood-clotting ability.
- Dietary fat enhances vitamin K absorption.
- Calcium and vitamin K help bone formation.
Forms Available
- Individual supplements as tablets
- Injectable forms administered by your clinician
- Supplements are not usually necessary since your diet and intestinal bacteria meet your normal requirements for vitamin K; besides, most supplements don't contain vitamin K.
|
|
|
|
|
Chemical Forms
- Vitamin K-1 (phylloquinone)
- Vitamin K-2 (menaquinone)
- Vitamin K-3 (menadione)
Comments On Vitamin K
- Vitamin K-1 (phylloquinone) comes from plants.
- Vitamin K-2 (menaquinone) comes from intestinal bacteria.
- The synthetic form, vitamin K-3 (menadione) is the most active form of the three.
- All forms of vitamin K are converted into menaquinone, the biologically active form.
- Vitamin K helps produce an important clotting factor called prothrombin.
- Vitamin K is not generally available in most multivitamins because most people meet their requirements from food and their intestinal bacteria.
|
|
|
|
|
Known Benefits of Vitamin K
- Essential for proper growth and development of bones.
- Prevents hemorrhaging in infants.
- Promotes normal blood clotting.
Unproven Claims
- Delays onset of osteoporosis.
- Enhances treatment of cancer with radiation therapy.
- May reduce risk of developing osteoporosis.
Vitamin K May Prevent These Signs of Deficiency
- Abnormal growth and development in infants
- Abnormal blood clotting hemorrhagic diseases
- Bruising easily
- Frequent nosebleeds
Recommended Dosage Range for Vitamin K
- Our pharmacists suggest that healthy adults may take 65 to 80 mcg to supplement a well-balanced diet.
- RDA values were set as the minimum needed to offset deficiency or disease, not as an actual value needed for optimum health.
- In the United States, the average consumption of vitamin K is 80 to 150 mcg per day.
- If taking more than 1,000 mcg per day of vitamin K, consult your physician.
- Consult your physician before starting any high-dose supplement regimen.
Dietary Sources
Food Tips
- Though more research needs to be done, vitamin K appears to be stable to light, heat, and air. So, you can cook and store food with little worry about losing vitamin K.
- Leafy green vegetables are the best source of vitamin K.
| Foods High in K | Serving Size | Amount of K | Units |
|---|
Beef liver
Broccoli, raw
Cabbage, raw
Cauliflower, raw
Soybean oil
Spinach, raw
Turnip greens, raw
Wheat germ
|
3 ounces
1/2 cup
1/2 cup
1/2 cup
1 tablespoon
1/2 cup
1/2 cup
1 ounce
|
89
58
52
96
76
74
182
10
|
mcg
mcg
mcg
mcg
mcg
mcg
mcg
mcg
|
When and How to Take Vitamin K
- Tablets should be swallowed whole with a glass of water.
- Take with food or after meals to enhance absorption.
What Not to Take with Vitamin K
- Mineral oil may lead to a deficiency in vitamin K.
- Excessive calcium doses or a calcium to phosphorus ratio above 2-to-1 interferes with vitamin K synthesis and/or absorption.
- Vitamin K deficiency may be exaggerated by high levels of vitamin E. This can result in hemorrhaging.
- Excessive doses of vitamin A inhibit vitamin K.
Storage
- Keep vitamin K in a cool, dry place away from direct sunlight and air.
- Don't freeze vitamin K.
- Don't store vitamin K in your bathroom medicine cabinet. Heat and moisture may make it less effective.
- Store safely out of children's reach.
Recommended Daily Allowance
| AGE/GROUP | RDA |
|---|
Infants
0 to 6 months
6 to 12 months
1 to 3 years
4 to 6 years
7 to 10 years
Males
11 to 14 years
15 to 18 years
19 to 24 years
25 to 50 years
51+ years
Females
11 to 14 years
15 to 18 years
19 to 24 years
25 to 50 years
51+ years
Pregnant
Lactating
1 to 6 months
6 to 12 months
|
mcg (micrograms)
5
10
15
20
30
45
65
70
80
80
45
55
60
65
65
65
65
65
|
|
|
|
|
|
|
Warnings
Consult a physician before use or do not use vitamin K if:- You're about to start a high dose supplement program.
May Have Interactions with the Following:
- Androgens: in test animals decrease prothrombin levels.
- Antacids containing aluminum: decrease absorption of fat soluble vitamins A, D, E, and K.
- Cholesterol lowering drugs: especially bile sequestering agents can cause deficiency of fat soluble vitamins, including vitamin K.
- Estrogens: in test animals increase prothrombin levels.
- Laxatives: prolonged use of mineral oil, phenolphthalein and DSS can cause deficiency of fat soluble vitamins, including vitamin K.
- Long-term IV feeding: requires vitamin K supplementation.
- Oral antibacterials: especially second- and third-generation cephalopsorins kill intestinal bacterial that synthesize vitamin K, and can cause delayed blood clotting.
- Primadone (mysoline): may lower plasma level of vitamin K.
- Vitamin A: in high doses adversely influences vitamin K function.
- Vitamin E: in high doses might exacerbate a borderline deficiency of vitamin K.
- Warfarin (coumadin): interferes with vitamin K utilization.
Side Effects
- Counteracts blood-thinning drugs.
- Only injected menadione is associated with more serious side effects and this is only available from a healthcare provider.
Signs of Overdose
- None anticipated.
- Oral forms of vitamin K have not been associated with overdose symptoms.
|
|
|
