WHAT IS VITAMIN K?
Vitamin K is a nutrient the body needs to stay healthy and is known as the ” blood-clotting vitamin” for its important role in wound healing. The “K” is derived from the German word koagulation. Vitamin K also plays an important role in bone health.
Vitamin K comes in two forms. The main form is called vitaminK1( phylloquinone), which is found in green leafy vegetables. The other type, vitamin K2(menaquinones), is found in some animal feeds and fermented foods. Vitamin K2 (menaquinones) can also be produced by bacteria in the human body.
HOW MUCH VITAMIN K DO I NEED?
The Recommended Daily Allowance (RDA) for vitamin K varies with age, gender, weight, and many other factors. Below are the average recommended daily amounts.
|Life Stage||Recommended Amount|
|Birth to 6 months||2.0 mcg|
|7–12 months||2.5 mcg|
|1–3 years||30 mcg|
|4–8 years||55 mcg|
|9–13 years||60 mcg|
|14–18 years||75 mcg|
|Adult men 19 years and older||120 mcg|
|Adult women 19 years and older||90 mcg|
|Pregnant or breastfeeding teens||75 mcg|
|Pregnant or breastfeeding women||90 mcg|
BENEFITS OF VITAMIN K
Vitamin K benefits the body in a variety of ways.
Vitamin K plays a key role in helping the blood clot
Vitamin K plays a role in blood clotting, bone metabolism, and the regulation of calcium levels in the blood. The body needs vitamin K to produce prothrombin, a protein, and a clotting factor that plays an important role in blood clotting and bone metabolism. People taking anticoagulant drugs, such as warfarin or Coumadin, should not start taking extra vitamin K without first talking to a doctor.
Vitamin K can interact with some medications, particularly warfarin (Coumadin®) and Antibiotics. Antibiotics can destroy the good bacteria in your intestine that make vitamin K. Using antibiotics for more than a few weeks can reduce the amount of vitamin K made in your intestine and therefore the amount available to your body.
Vitamin K can increase bone mineral density and reduce fracture rates
Vitamin K is important for healthy bones. A 2019 observational study1 published on Hindawi Journal of Osteoporosis found that low vitamin K intake, low serum vitamin K values, are associated with risk of fracture (especially hip fracture) and lower Bone Mineral Density (BMD).
Vitamin K may exert significant effects on the cognitive functions
Increased blood levels of vitamin K have been associated with improved episodic memory in the elderly.
A 2013 study 2 found evidence of the possible role of vitamin K in cognition during aging, particularly in the consolidation of memory traces. The purpose of the study was to examine associations between vitamin K status, as measured by serum phylloquinone concentrations, and performance of episodic verbal and nonverbal memory, executive function, and processing speed. The sample included 320 men and women aged 70 to 85 years who were not cognitively impaired.
After adjustment for covariates, higher serum phylloquinone concentration was associated with better performance of episodic verbal memory. No association was found with episodic nonverbal memory, executive function, and processing speed.
Another study in 20193 evaluated vitamin K intake using a semi-quantitative Dietary Frequency Questionnaire (FFQ). the result of the study showed a decrease in subjective memory impairment as well as improved cognition and fewer behavioral problems in geriatric patients with higher vitamin K intakes.
Vitamin K may prevent vascular calcifications
Vitamin K can help keep blood pressure lower by preventing mineralization, where minerals accumulate in the arteries. This allows the heart to pump blood freely through the body. A 2015 study4 has shown that vitamin k deficiency increases the risk of vascular calcification. Diets lacking vitamin K can precipitate the development of vitamin K deficiency in as little as 7 days.
Sub-clinical vitamin K deficiency is common, especially in patients receiving warfarin. Thus, dietary intake of vitamin K1 (phylloquinone, the main dietary source of vitamin K) without vitamin K2 (menaquinone) may not be sufficient to suppress arterial calcification and/or reduce the risk of cardiovascular events and subsequent death. The menaquinone form of vitamin K (i.e., vitamin K2) has been presumed to be more effective than vitamin K1 in preventing and reversing arterial calcification.
Bacteria in the gastrointestinal tract naturally make vitamin K. But vitamin K is found also in many foods such as:
Green leafy vegetables such as spinach, kale, broccoli and lettuce, mustard greens, parsley, turnip greens – broccoli, Brussels sprouts. vegetable oils, meat, cheese, eggs, and soybeans, certain fruits such as blueberries and figs and cereals.
VITAMIN K DEFICIENCY
Dietary vitamin K deficiency is rare in healthy people. The most common causes of vitamin K deficiency are insufficient dietary intake, inadequate absorption, and reduced storage of the vitamin due to liver disease, but it can also be caused by decreased production in the intestines.
In general, people with a deficiency are unable to properly absorb the vitamin K produced naturally in the intestinal tract. People who suffer from serious gastrointestinal disorders, such as gallbladder disease, cystic fibrosis, celiac disease, or Crohn’s disease, are unable to absorb vitamin K properly and are therefore more likely to be deficient.
Vitamin K deficiency can cause excessive bleeding, which can start in the nose or gums. Other symptoms can include easy bruising, blood in the urine, and stool.
SIGNS YOU MAY HAVE A VITAMIN K DEFICIENCY
Vitamin K deficiency can cause bruising and bleeding problems because the blood takes longer to clot. Vitamin K deficiency can reduce bone strength and increase the risk of osteoporosis because the body needs vitamin K for healthy bones.
Vitamin K deficiency may include the following signs and symptoms:
• Easy bruising
• Oozing from nose or gums
• Excessive bleeding from wounds, punctures, injection sites or surgery
• Heavy menstruation
• Presence of blood in urine and/or stool
• Prothrombin time increase (PT/INR)
• Gastrointestinal (GI) tract hemorrhage
According to the Harvard School of Public Health, Vitamin K is found in multivitamin/multimineral supplements. Vitamin K is also available in vitamin K supplements alone or vitamin K supplements with some other nutrients such as calcium, magnesium and/or vitamin D. Common forms of vitamin K in dietary supplements are phylloquinone and phytonadione (United States Pharmacopeia generic name for vitamin K1), menaquinone-4 and menaquinone-7 (also called vitamin K2).
1– Celia Rodríguez-Olleros Rodríguez, Manuel Díaz Curiel,Vitamin K, and Bone Health: A Review on the Effects of Vitamin K Deficiency and Supplementation and the Effect of Non-Vitamin K Antagonist Oral Anticoagulants on Different Bone Parameters. Volume 2019 |Article ID 2069176 | 8 pages | https://doi.org/10.1155/2019/2069176
2013 Dec;34(12):2777-83. DOI: 10.1016/j.neurobiolaging. 2013.05.031. Epub 2013 Jul 11.Vitamin K status and cognitive function in healthy older adults,