What is Vitamin K: Benefits, Dosage, and Uses

Quick Health Scoop

• Vitamin K comes in two primary forms: Vitamin K1 and Vitamin K2.
• While the body can also produce some Vitamin K through gut bacteria, food sources of Vitamin K include leafy green vegetables, animal foods, and fermented foods.
• Certain people face an increased risk of low Vitamin K status, including newborns, people taking Vitamin K antagonists, people with certain health issues and those who have had weight loss surgery.
• The benefits of Vitamin K include supporting normal blood clotting, bone health, and heart health.^†

Unlike more “famous” nutrients like Vitamin A and Vitamin E, you might not know much about Vitamin K. Yes, it’s one of the 13 essential vitamins your body for good health. But exactly

what is Vitamin K? What foods contain Vitamin K? And what are the benefits of Vitamin K? Read on to find out.

What Is Vitamin K?

Vitamin K is actually more than one vitamin, similar to the B vitamin family. Vitamin K encompasses a group of compounds with a common chemical structure and occurs naturally in some foods (such as green leafy vegetables). [1] It’s also available as a dietary supplement. This fat-soluble vitamin comes in two naturally occurring forms: phylloquinone (Vitamin K1) and menaquinones (Vitamin K2). [2] Your body stores Vitamin K in the liver and other tissues (such as the brain, heart, and bone).

Food sources of Vitamin K1 include leafy green vegetables (think collard greens, kale, and spinach), while food sources of Vitamin K2 include animal foods, and fermented foods (like kimchi, cheese, and sauerkraut). The body can also produce Vitamin K2 via bacteria in the gut. [4]

Signs Of Low Vitamin K

Health experts recommend that adults (ages 19 and older) get 120 micrograms (mcg) of Vitamin K every day for men and 90 mcg of daily Vitamin K for women (including pregnant or lactating females). [4]

Significantly low levels of Vitamin K can cause bruising and blood issues because the blood will take longer to coagulate. For instance, people with low Vitamin K status may notice blood on the gums (for females) or a heavy menstrual flow. [5] Because your body requires Vitamin K for healthy bones, low Vitamin K might also decrease bone strength and increase the bone health risks. [6]

While it’s uncommon for healthy adults to have low Vitamin K levels, certain people face an increased risk, including: [2,6]

• Newborns who don’t receive Vitamin K injection at birth
• People taking Vitamin K antagonists
• People with significant liver damage or liver disease
• People with malabsorption disorders
• People who have had bariatric (weight loss) surgery

Low Vitamin K levels can occur during the first few weeks of infancy for several reasons, including low placental transfer of the nutrient, low coagulation factor levels, and low Vitamin K content of breast milk. [1] Because of this, the American Academy of Pediatrics recommends that routine Vitamin K prophylaxis be given to newborns, which is why infants are typically given a Vitamin K injection at birth. [7]

Having any of the above health problems can affect your Vitamin K status. As always, it’s best to get your nutrients—including Vitamin K—from food sources. However, if you have low Vitamin K levels, ask your healthcare professional about Vitamin K supplementation.

Vitamin K can interfere with certain medications (such as Coumadin), so make sure your Vitamin K intake is about the same every day. [6]

4 Vitamin K Benefits And Uses

A primary function of this important nutrient is to activate proteins that play key roles in blood clotting. It can also help support, bone health, and heart health. [3] In fact, Vitamin K and Vitamin K-dependent proteins are best known for the pivotal role they play in blood coagulation. [1]

Whether you get your Vitamin K from food or a Vitamin K supplement, this key nutrient plays a variety of important roles in the body. [1,2,8]

1. Vitamin K helps your blood coagulate -and supports healthy artery and vascular functions. ^†
2. Vitamin K works together with Vitamin D to activate proteins that help support healthy bone
3. Vitamin K also helps regulate calcium deposition, which supports healthy bone ^†
4. Vitamin K helps maintain a healthy circulatory system. ^†

Bottom Line

As a lesser-known nutrient, Vitamin K comes in two primary forms: Vitamin K1 and Vitamin K2.

The body can produce some Vitamin K through bacteria in the lower intestine. Vitamin K food sources include leafy green vegetables, animal foods, and fermented foods. While deficient Vitamin K status isn’t common, certain people face an increased risk of low levels, including people taking Vitamin K antagonists, people with certain health issues (such as liver damage and malabsorption disorders) and those who have had weight loss surgery. What are the health benefits of Vitamin K? This key nutrient plays an important role in blood clotting and supports bone health and heart health.

Continue to check back on the Nature Made blog for the latest science-backed articles to help you take ownership of your health.

† These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.

References 

1. National Institutes of Health. “Vitamin K: Fact Sheet for Health Professionals.” March 29, 2021. Accessed on: July 19, 2022. https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
2. Oregon State University Linus Pauling Institute. “Vitamin K.” August 2014. Accessed on: July 19, 2022. https://lpi.oregonstate.edu/mic/vitamins/vitamin-K#reference35
3. “Vitamin K1 vs K2: What’s the Difference?” September 15, 2017. Accessed on: July 20, 2022. https://www.healthline.com/nutrition/vitamin-k1-vs-k2
4. Harvard T.H. Chan School of Public Health. “Vitamin K.” 2022. Accessed on: July 19, 2022. https://www.hsph.harvard.edu/nutritionsource/vitamin-k/
5. Cleveland Clinic. “All About Vitamin Deficiencies with Dr. Kelly Raj.” March 11, 2020. Accessed on: July 20, 2022. https://my.clevelandclinic.org/podcasts/health-essentials/all-about-vitamin-deficiencies-with-dr-kelly-raj
6. National Institutes of Health. “Vitamin K: Fact Sheet for Consumers.” March 22, 2021. Accessed on: July 20, 2022. https://ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
7. “Vitamin K and the Newborn Infant.” March 2022. Accessed on: July 20, 2022. https://publications.aap.org/pediatrics/article/149/3/e2021056036/184866/Vitamin-K-and-the-Newborn-Infant
8. “Vitamin K and bone health.” October 2001. Accessed on: July 20, 2022. https://www.sciencedirect.com/science/article/abs/pii/S0899900701007092