A fat-soluble vitamin called vitamin K is essential for human health, especially for bone health, blood coagulation, and general well-being. There are two main types of vitamin K:
Vitamin K1 (Phylloquinone): Predominantly sourced from green leafy vegetables like spinach, kale, and broccoli, it constitutes the primary dietary supply of vitamin K.
Vitamin K2 (Menaquinone): Derived from specific gut bacteria, vitamin K2 is prevalent in animal-based foods and fermented items, featuring subtypes such as MK-4 and MK-7.
What crucial functions does vitamin K cover?
Blood Clotting: Vitamin K plays a critical part in the liver's synthesis of numerous clotting factors, including prothrombin and various proteins. These factors are indispensable for effective blood clotting, thereby averting excessive bleeding following injuries.
Bone Health: Vitamin K is integral to bone metabolism. It activates osteocalcin, a protein pivotal in binding calcium to the bone matrix. This process contributes to stronger bones, reducing fracture risk and enhancing bone density.
Calcium Regulation: By ensuring the appropriate deposition of calcium in bones and teeth, vitamin K regulates calcium levels in the body. This regulation diminishes the likelihood of conditions such as osteoporosis and arterial calcification.
Cell Growth and Well-being: Vitamin K's involvement in cellular processes extends to potential roles in cell growth regulation and disease prevention.
Anti-Inflammatory Properties: Emerging research indicates that vitamin K may possess anti-inflammatory characteristics. This could potentially mitigate the risk of chronic inflammatory-related diseases.
Brain Health: Ongoing studies are delving into vitamin K's potential significance in brain health and neuroprotection, although further investigation is imperative in this domain.
It's essential to note that vitamin K deficiency is a rarity among healthy adults, mainly due to its presence in commonly consumed foods. Nonetheless, specific groups, including individuals with certain medical conditions, those using particular medications (like blood thinners), and newborns (who might have limited vitamin K levels at birth), are susceptible to deficiency. These groups may necessitate supplements or medical intervention.
Signs of Vitamin K Deficiency:
Increased Bleeding and Bruising: A prominent indication of a lack of vitamin K is an elevated tendency to bleed, even from minor wounds or cuts. This may manifest as:
Epistaxis (nosebleeds)
Bleeding gums
Easily formed bruises
Prolonged bleeding following injuries or surgeries
Presence of blood in urine or stool
Gastrointestinal Bleeding: Insufficient vitamin K levels can lead to bleeding within the gastrointestinal tract, characterized by:
Dark, tarry stools known as melena
Blood in the stool, termed hematochezia
Heavy Menstrual Bleeding: In females, inadequate vitamin K can contribute to excessive menstrual bleeding (menorrhagia).
Delayed Blood Clotting: Vitamin K is vital for synthesizing clotting factors in the liver. Deficiency may result in prolonged clotting time and delayed wound healing.
Osteoporosis and Fractures: Vitamin K is also implicated in bone health, facilitating the deposition of calcium in bones. A deficiency may weaken bones, heightening the risk of fractures.
Calcification of Soft Tissues: In severe deficiency cases, calcium might accumulate in soft tissues and blood vessels, termed ectopic calcification. This can potentially contribute to cardiovascular issues.
Risk of Hemorrhagic Disease of the Newborn (HDN): Newborns are particularly susceptible to vitamin K deficiency, which can trigger HDN. This condition can lead to bleeding in an infant's brain and other organs, posing serious health threats.
It's essential to recognize that vitamin K deficiency is uncommon in healthy adults who maintain a balanced diet, given the widespread presence of this vitamin in various foods like green leafy vegetables, oils, and select animal-based products. Nonetheless, specific factors can elevate the risk of deficiency, including:
Inadequate intake of vitamin K-rich foods.
Digestive disorders impeding vitamin K absorption.
Extended use of particular medications like antibiotics that can disrupt gut bacteria involved in vitamin K production.
Liver-related conditions affecting the synthesis of clotting factors.
Types of Vitamin K and their Food Sources:
Vitamin K1 (Phylloquinone):
Source: Predominantly sourced from plant-based foods.
Common Dietary Sources:
Green Leafy Vegetables: Spinach, kale, collard greens, Swiss chard, and broccoli are renowned for their richness in vitamin K1.
Other Vegetables: While in lower quantities, Brussels sprouts, cabbage, asparagus, and green peas also provide vitamin K1.
Plant Oils: Specific vegetable oils like soybean oil and canola oil are carriers of vitamin K1.
Function: Primarily involved in facilitating blood clotting by supporting the production of clotting factors in the liver.
Vitamin K2 (Menaquinone):
Source: Synthesized by gut bacteria and present in both animal-based and fermented foods.
Notable Dietary Sources:
Fermented Foods: Natto, a fermented soybean dish, stands out as an exceptional source of vitamin K2, particularly the MK-7 subtype. Other fermented foods like cheese, sauerkraut, and kefir may also contain varying amounts.
Animal-Based Foods: Meat, liver, eggs, and dairy products, with an emphasis on cheese and butter, are contributors to vitamin K2.
Fish: Certain fatty fish, including salmon and mackerel, harbor vitamin K2.
Function: Vitamin K2 aids in regulating calcium metabolism, directing calcium to reinforce bones and teeth while preventing its harmful accumulation in soft tissues and blood vessels. This has a critical impact on both bone and cardiovascular health.
Vitamin K3 (Menadione):
Source: This form of vitamin K is synthetic.
Usage: Vitamin K3 is not typically present in natural dietary sources. Instead, it finds utility in some supplements and fortified foods, as well as in animal feed.
It's worth highlighting that while vitamin K1 is integral to blood clotting and vitamin K2 plays a pivotal role in bone and cardiovascular health, both variants contribute to overall vitamin K intake in the body.
Additionally, the body has the capacity to convert some vitamin K1 into vitamin K2. To ensure an ample vitamin K intake, adopting a well-rounded diet featuring diverse foods, particularly green leafy vegetables for vitamin K1 and fermented or animal-based items for vitamin K2, is advisable.
Age GroupGender RDA (micrograms, mcg):
AGE GROUP | RDA (micrograms, mcg) |
Infants (0-6 months) | 2.0 mcg |
Infants (7-12 months) | 2.5 mcg |
Children (1-3 years) | 30 mcg |
Children (4-8 years) | 55 mcg |
Age group (9-13 years) | 60 mcg |
Age group (14-18 years) | 75 mcg |
Males (19 years and older) | 120 mcg |
Females (19 years and older) | 90 mcg |
Pregnant Teens (14-18 years) | 75 mcg |
Pregnant Adults (19 years and older) | 90 mcg |
Lactating Teens (14-18 years) | 75 mcg |
Lactating Adults (19 years and older) | 90 mcg |
Benefits of Vitamin K for Health:
Blood Clotting:
Coagulation: Vitamin K is indispensable for synthesizing various clotting factors within the liver. These factors are imperative for orchestrating blood coagulation, the body's innate defense against bleeding when injuries occur.
Hemorrhage Prevention: Ensuring sufficient vitamin K intake is paramount for robust blood clot formation, mitigating the risk of excessive bleeding following wounds or trauma.
Bone Health:
Calcium Regulation: Vitamin K plays a pivotal role in regulating calcium metabolism. It facilitates the activation of osteocalcin, a protein that binds calcium to the bone matrix. This fortifies bones, diminishing the susceptibility to osteoporosis.
Fracture Prevention: Existing research posits that maintaining optimal vitamin K levels may serve as a preventive measure against fractures while enhancing bone density.
Cardiovascular Health:
Calcium Redistribution: Vitamin K2, notably, spearheads the redirection of calcium away from amassing within blood vessels and soft tissues. This action potentially curtails the risk of arterial calcification and cardiovascular ailments.
Heart Health: Some investigations propose that vitamin K may exert a positive influence on heart health by fostering the well-being of blood vessels and mitigating inflammation.
Cognitive Health:
Brain Function: Ongoing research delves into the potential role of vitamin K in sustaining cognitive health and providing neuroprotection. Although this realm necessitates further exploration, the antioxidant properties inherent to vitamin K may augur well for brain function.
Potential Anti-Inflammatory Properties:
There is evidence hinting at the anti-inflammatory potential of vitamin K. This attribute may be of particular benefit to individuals grappling with conditions associated with chronic inflammation.
Blood Sugar Regulation:
Preliminary studies propose that vitamin K could play a part in enhancing insulin sensitivity and regulating blood sugar levels. However, more comprehensive investigations are requisite to corroborate these potential advantages.
Tips for Increasing Vitamin K Intake:
Incorporate Leafy Greens: Boost your vitamin K intake with green leafy vegetables, such as spinach, kale, Swiss chard, collard greens, and broccoli.
Explore Other Vegetables: While leafy greens are prime sources of vitamin K1, consider adding Brussels sprouts, asparagus, and green peas to your diet.
Choose Healthy Oils: Certain vegetable oils like soybean and canola oil contain vitamin K1. Utilize them in cooking or salad dressings.
Leverage Fresh Herbs: Enhance your vitamin K consumption by using fresh herbs like parsley, basil, cilantro, and sage as seasonings or garnishes.
Embrace Fermented Foods: Include fermented items like natto, sauerkraut, and kimchi in your diet to access vitamin K2.
Include Dairy and Cheese: Incorporate dairy products and cheese, particularly hard cheeses like Gouda and cheddar, to your snacks and meals for vitamin K2.
Consider Animal-Based Foods: Meats and liver contain modest amounts of vitamin K2, contributing to overall intake.
Blend Green Smoothies: Blend leafy greens with fruits to create nutritious and vitamin K-rich smoothies.
Design Vibrant Salads: Construct salads using a medley of greens and vegetables, adding nuts, seeds, or cheese for flavor and nutrition.
Opt for Healthy Snacks: Choose vitamin K-rich snacks such as kale chips, broccoli florets with hummus, or celery sticks paired with peanut butter.
Check Nutritional Labels: Scrutinize food labels for vitamin K content, particularly in fortified and packaged foods.
Select Appropriate Cooking Methods: Opt for cooking methods like steaming or sautéing vegetables to retain more vitamin K, compared to boiling, where nutrients can leach into the cooking water.
Diversify Your Diet: Maintain a diverse diet featuring various vitamin K-rich foods to ensure adequate intake.
Consult a Dietitian: Seek guidance from a registered dietitian, especially if you have specific dietary needs or medical conditions affecting nutrient absorption.
Note: While these benefits are promising, individual dietary needs and health conditions can influence the extent to which vitamin K exerts its positive effects. Consulting healthcare professionals for tailored dietary guidance and health recommendations is always prudent.
REFERENCE Booth SL, Suttie JW. Dietary intake and adequacy of vitamin K. J Nutr. 1998;128(5):785-788.
Shearer MJ, Newman P. Metabolism and cell biology of vitamin K. Thromb Haemost. 2008;100(4):530-547.
Ferland G. Vitamin K and the nervous system: An overview of its actions. Adv Nutr. 2012;3(2):204-212.
Vermeer C. Vitamin K: The effect on health beyond coagulation – an overview. Food Nutr Res. 2012;56:5329.
Beulens JW, Booth SL, van den Heuvel EG, Stoecklin E, Baka A, Vermeer C. The role of menaquinones (vitamin K₂) in human health. Br J Nutr. 2013;110(8):1357-1368.
Palermo A, Tuccinardi D, D'Onofrio L, et al. Vitamin K and osteoporosis: Myth or reality? Metabolism. 2017;70:57-71.
Sato T, Schurgers LJ, Uenishi K. Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. Nutr J. 2012;11:93.
Iwamoto J, Sato Y, Takeda T, Matsumoto H. High-dose vitamin K supplementation reduces fracture incidence in postmenopausal women: A review of the literature. Nutr Res. 2009;29(4):221-228.
Shah NP. Effects of milk-derived bioactives: An overview. Br J Nutr. 2000;84 Suppl 1:S3-10.
Schurgers LJ, Teunissen KJ, Hamulyák K, Knapen MH, Vik H, Vermeer C. Vitamin K-containing dietary supplements: Comparison of synthetic vitamin K1 and natto-derived menaquinone-7. Blood. 2007;109(8):3279-3283.
Cockayne S, Adamson J, Lanham-New S, Shearer MJ, Gilbody S, Torgerson DJ. Vitamin K and the prevention of fractures: Systematic review and meta-analysis of randomized controlled trials. Arch Intern Med. 2006;166(12):1256-1261.
Rasekhi H, Karandish M, Jalali MT, et al. Phylloquinone supplementation improves glycemic status independent of the effects of adiponectin levels in premonopause women with prediabetes: A double-blind randomized controlled clinical trial. J Diabetes Metab Disord. 2015;15:16.
Bolton-Smith C, McMurdo ME, Paterson CR, et al. Two-year randomized controlled trial of vitamin K1 (phylloquinone) and vitamin D3 plus calcium on the bone health of older women. J Bone Miner Res. 2007;22(4):509-519.
Kimura S, Uchiyama S. The role of vitamin K in the treatment of postmenopausal osteoporosis. Curr Drug Saf. 2007;2(2):151-156.
Shea MK, O'Donnell CJ, Hoffmann U, et al. Vitamin K supplementation and progression of coronary artery calcium in older men and women. Am J Clin Nutr. 2009;89(6):1799-1807.
Iwamoto J, Takeda T, Ichimura S. Effect of combined administration of vitamin D3 and vitamin K2 on bone mineral density of the lumbar spine in postmenopausal women with osteoporosis. J Orthop Sci. 2000;5(6):546-551.
Vermeer C, Raes J, Van't Hoofd C, Knapen MH, Xanthoulea S. Menaquinone content of cheese. Nutrients. 2018;10(4):446.
Comments