Vitamin K - Side Effects

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a7_3star Reliable and relatively consistent scientific data showing a substantial health benefit.

a7_2star Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.

a7_1star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

This supplement has been used in connection with the following health conditions:

Used for	Amount	Why
Atherosclerosis (Vitamin K1, for coronary calcification )	500 mcg per day of vitamin K1	In a double-blind trial, supplementing with vitamin K1 for three years appeared to slow the rate of progression of coronary artery calcification in seniors.
Atherosclerosis 500 mcg per day of vitamin K1 In a double-blind trial, supplementing with vitamin K1 for three years appeared to slow the rate of progression of coronary artery calcification in elderly people who had preexisting coronary artery calcification. Participants in that study were randomly assigned to receive a multivitamin that contained 500 mcg per day of vitamin K1 or the same multivitamin without vitamin K1.² Learn More

Used for	Amount	Why
Celiac Disease and Vitamin K Deficiency	Consult a qualified healthcare practitioner	The malabsorption that occurs in celiac disease can lead to multiple nutritional deficiencies. Supplementing with vitamin K may correct a deficiency.
Celiac Disease and Vitamin K Deficiency Consult a qualified healthcare practitioner The malabsorption that occurs in celiac disease can lead to multiple nutritional deficiencies. The most common nutritional problems in people with celiac disease include deficiencies of essential fatty acids, iron, vitamin D, vitamin K, calcium, magnesium, and folic acid.³ Zinc malabsorption also occurs frequently in celiac disease⁴ and may result in zinc deficiency, even in people who are otherwise in remission.⁵ People with newly diagnosed celiac disease should be assessed for nutritional deficiencies by a doctor. Celiac patients who have not yet completely recovered should supplement with a high-potency multivitamin-mineral. Some patients may require even higher amounts of some of these vitamins and minerals—an issue that should be discussed with their healthcare practitioner. Evidence of a nutrient deficiency in a celiac patient is a clear indication for supplementation with that nutrient. After commencement of a gluten-free diet, overall nutritional status gradually improves. However, deficiencies of some nutrients may persist, even in people who are strictly avoiding gluten. For example, magnesium deficiency was found in 8 of 23 adults with celiac disease who had been following a gluten-free diet and were symptom-free. When these adults were supplemented with magnesium for two years, their bone mineral density increased significantly.⁶

Used for	Amount	Why
Crohn’s Disease	80 to 1,000 mcg daily	Taking vitamin K can counteract the deficiency and resulting bone loss that can occur in people with Crohn’s disease.
Crohn’s Disease 80 to 1,000 mcg daily In people with Crohn's disease, vitamin K deficiency can result from malabsorption due to intestinal inflammation or bowel surgery, from chronic diarrhea, or from dietary changes necessitated by food intolerance. In addition, Crohn's disease is often treated with antibiotics that have the potential to kill beneficial vitamin K–producing bacteria in the intestines. Vitamin K levels were significantly lower in a group of people with Crohn's disease than in healthy people. Moreover, the rate of bone loss in the Crohn's disease patients increased with increasing degrees of vitamin K deficiency.⁷ When combined with earlier evidence that vitamin K is required to maintain healthy bones, this study suggests that vitamin K deficiency is a contributing factor to the accelerated bone loss that often occurs in people with Crohn's disease. Learn More

Used for	Amount	Why
Cystic Fibrosis	5 mg every three days	The fat malabsorption associated with cystic fibrosis often leads to a deficiency of fat-soluble vitamins, such as vitamin K. Supplementation can help counteract the deficiency.
Cystic Fibrosis 5 mg every three days The fat malabsorption associated with CF often leads to a deficiency of fat-soluble vitamins. Oral supplementation of these nutrients is considered crucial to maintaining good nutritional status.⁸ Current recommendations for supplementation are as follows: vitamin A, 5,000 to 10,000 IU/day; vitamin D, 1,000 to 2,000 IU/day; vitamin E, 100 to 300 IU/day; and vitamin K, 5 mg every three days. Of the water-soluble vitamins, only vitamin B12 is poorly absorbed in cystic fibrosis,⁹ and taking pancreatic enzymes helps prevent B12 deficiencies.¹⁰ Learn More

Used for	Amount	Why
Osteoporosis	1,000 mcg daily	Vitamin K is needed for bone formation, and supplementing with it may be a way to maintain bone mass.
Osteoporosis 1,000 mcg daily Vitamin K is needed for bone formation. People with osteoporosis have been reported to have low blood levels¹¹^{, 12} and low dietary intake of vitamin K.¹³^{, 14} One study found that postmenopausal (though not premenopausal) women may reduce urinary loss of calcium by taking 1 mg of vitamin K per day.¹⁵ People with osteoporosis given large amounts of vitamin K2 (45 mg per day) have shown an increase in bone density after six months¹⁶ and decreased bone loss after one¹⁷ or two¹⁸ years. Other preliminary studies have reported that vitamin K supplementation increases bone formation in some women¹⁹ and that higher vitamin K intake correlates with greater bone mineral density.²⁰ However, a double-blind study found that supplementing with 500 mcg of vitamin K1 per day for three years had no effect on bone mineral density, when compared with a placebo.²¹ Some doctors recommend 1 mg vitamin K1 to postmenopausal women as a way to help maintain bone mass, though optimal intake remains unknown. Learn More

Used for	Amount	Why
Morning Sickness	Refer to label instructions	Vitamin K and vitamin C, taken together, may provide relief of morning sickness symptoms for some women.
Morning Sickness Vitamin K and vitamin C, taken together, may provide relief of symptoms for some women. In one study, 91% of women who took 5 mg of vitamin K and 25 mg of vitamin C per day reported the complete disappearance of morning sickness within three days.²² Menadione was removed from the market a number of years ago because of concerns about potential toxicity. Although some doctors still use a combination of vitamin K1 (the most prevalent form of vitamin K in food) and vitamin C for morning sickness, no studies on this treatment have been done. Learn More

Used for	Amount	Why
Phenylketonuria and Vitamin K Deficiency	Refer to label instructions	People with PKU may be deficient in vitamin K, due to the restricted PKU diet. Supplementing with vitamin K may correct a deficiency.
Phenylketonuria and Vitamin K Deficiency People with PKU may be deficient in several nutrients, due to the restricted diet which is low in protein and animal fat. Deficiencies of long-chain polyunsaturated fatty acids (LC-PUFAs),²³ ^{, 24} ^{, 25} selenium,²⁶ ^{, 27} ^{, 28} ^{, 29} vitamin B12,³⁰ and vitamin K may develop on this diet.³¹ Because the PKU diet is low in animal products, fat intake is also significantly reduced. The results of a preliminary study of children with PKU suggested that the low-fat PKU diet intake may impair the absorption of vitamin K, a fat-soluble vitamin, from the diet, possibly resulting in a vitamin K deficiency. In that study, children with PKU on a strict diet had low levels of certain vitamin K-dependent proteins needed for normal blood clotting.³²

Also indexed as:

vitamin K,
vitamin K1

About this treatment

Side Effects

Allergic reactions to vitamin K injections have been reported on rare occasions.

References

Last Review: 05-11-2011

Learn more about Aisle7, the company.

The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2011.

© 1995-2011 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

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