Certain fat malabsorption disorders may put you at higher risk of a deficiency.
Vitamin K is a fat-soluble vitamin that plays a role in blood clotting in the body. Most people get the amount of vitamin K they need through diet alone, but it is injected as a supplement in newborns, as they do not produce vitamin K right away, nor do they get sufficient amounts from breast milk.
Vitamin K comes in two forms: vitamin K1 (phylloquinone) found in some foods, and vitamin K2 (menaquinones). which is synthesized by the bacteria found in the intestines. It is fat-soluble, which means it is absorbed with fat and the body stores it for later use.
There is little research to suggest that vitamin K supplementation can play a role in disease prevention. The main use of supplemental vitamin K is to treat a vitamin K deficiency, which is rare in the United States.
Vitamin K is routinely provided as an intramuscular (IM) injection to newborns to prevent deficiency. The American Academy of Pediatrics recommends that vitamin K be given within the first six hours of life to all newborns.
No supplement is intended to treat, cure, or prevent disease. However, vitamin K has also been researched for its role in:
Vitamin K helps produce the proteins in the body that are essential for blood clotting. Vitamin K therapy has been used to reverse the effects of anticoagulants (blood thinners).
An example of this may be someone prescribed anticoagulants who suddenly requires emergency surgery. In this case, 2.5 to 5 milligrams (mg) of vitamin K can be administered to reverse the anticoagulation effects and prevent excess bleeding.
Vitamin K is thought to contribute to bone health due to its role in producing proteins responsible for bone formation. However, there is not enough research on vitamin K to show whether vitamin K supplementation plays a direct role in improving bone health or preventing osteoporosis.
Results of research on vitamin K for osteoporosis prevention are mixed and include:
Research on vitamin K supplementation for heart disease prevention has been inconclusive.
Vitamin K has a role in the formation of a protein called matrix Gla-protein (MGP). MGP blocks vascular calcification (mineral deposits in the walls of the arteries and veins), but it depends on vitamin K for activation. Vascular calcification is associated with an increased risk of heart disease.
However, it is still unclear whether supplementing vitamin K can slow vascular calcification.
Furthermore, a review in the Cochrane Database concluded that there is not enough evidence to support the use of vitamin K in the primary prevention of heart disease.
Vitamin K deficiency is rare in adults but happens often in infants.
Newborns are routinely given a standard vitamin K injection right after birth to prevent deficiency. This is because:
In adults, vitamin K deficiency is most often related to malabsorption disorders. People with malabsorption disorders like cystic fibrosis (CF), celiac disease, Crohn's disease, and short bowel syndrome may need supplemental vitamin K.
A vitamin K deficiency can occur from inadequate intake or poor absorption in the gastrointestinal (GI) tract.
Most people get enough vitamin K in their diets. The bacteria in our GI tract also produce vitamin K.
Poor absorption of vitamin K occurs secondary to a GI condition or malabsorption (difficulty in absorbing or digesting nutrients). Poor absorption may also be a side effect of some medications.
Those at greatest risk of a vitamin K deficiency include:
People with a deficiency as a result of fat malabsorption should take an oral supplement of vitamin K in a water-soluble form.
Although rare, there are a few case reports of vitamin K deficiency and complications in people and their infants after experiencing hyperemesis (severe nausea and vomiting) during pregnancy.
Vitamin K status can be evaluated by assessing dietary intake and absorption.
If you have a GI condition or fat malabsorption, you are at greater risk of vitamin K deficiency. Symptoms of malabsorption include frequent diarrhea, light-colored stools, and weight loss.
Vitamin K levels in the blood are not routinely assessed in most people, nor are they a good way to measure for vitamin K.
Prothrombin time is an indicator of vitamin K status. Prothrombin time is a measure of the time it takes blood to clot. In those prescribed anticoagulants, prothrombin times are routinely assessed to monitor the effectiveness of anticoagulant dosing.
Someone with a vitamin K deficiency will also bruise or bleed more easily. Although uncommon, ecchymosis or petechiae (skin conditions) may also be present.
Vitamin K supplements aren't recommended unless your healthcare provider indicates you need additional vitamin K. Side effects of supplementing vitamin K are rare when taken at the recommended dose.
There may be side effects of taking vitamin K and medications such as blood thinners, aspirin, antibiotics, and more. Taking vitamin K with blood thinners can make the medication less effective. Antibiotic use may block the action of and reduce vitamin K status in the body.
Since vitamin K works to clot the blood, those prescribed the blood-thinning medication Jantoven (warfarin) or those with clotting disorders must be mindful of their vitamin K intake.
Adding more vitamin K to your usual intake will make the medications less effective. It is important to keep your vitamin K intake consistent.
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your needs.
Most people can meet their vitamin K needs through diet alone. For supplementation, dosing can vary depending on the cause of the deficiency.
At birth, newborns routinely receive a 0.5 to 1 mg vitamin K intramuscular injection to prevent a deficiency.