Vitamin K: Sources, Forms, Benefits, Dosage & Deficiency Symptoms

Article at a Glance

• Vitamin K is one of the 13 essential vitamins you need in your diet for heart and bone health.
• There are three forms of vitamin K: vitamin K1, vitamin K2, and vitamin K3.
• You can get vitamin K from different plant and animal food sources, nutrition supplements, and it is also produced in your large intestine.
• Vitamin K deficiency is rare in adults, but it can cause serious symptoms such as excessive bleeding and easy bruising.

Have you ever cut yourself so badly that you wondered when and how you would finally stop bleeding? Vitamin K plays a major role in blood clotting, and it is even known as the “clotting” vitamin. [1] Read more below to understand vitamin K’s functions, benefits, and sources.

What Is Vitamin K?

Vitamin K is one of the 13 essential vitamins needed in your diet because your body cannot make enough on its own. [1] Along with being essential, vitamin K is fat-soluble and fat-soluble vitamins are stored in your liver or fat tissue. Since these vitamins are not easily flushed from your body like water-soluble vitamins, they have the potential to accumulate and cause toxic side effects. No need to stress as vitamin K toxicity is very rare, and you would have to take excessively high amounts of vitamins to reach toxicity levels.

Why Is Vitamin K important?

Vitamin K is essential for many physiological functions:

• Helps make a protein called prothrombin, which plays a critical role in blood clotting to prevent excessive bleeding and allows your skin to heal after a cut.
• Prevents vascular calcification, which is the buildup of calcium in your veins and arteries. [1][2] According to studies it can also help prevent heart disease. [3]
• Supports many aspects of bone health, such as bone density, formation, and repair. Research shows that vitamin K can help prevent osteoporosis. [3][4][5] 
• Beneficial for teeth.

The Forms of Vitamin K

There are three forms of vitamin K:[1,4,8]

1. Vitamin K1 (phylloquinone) — Found mostly in plant food sources. This form is beneficial for blood clotting, but your body does not optimally absorb this form and it’s easily excreted.
2. Vitamin K2 (menaquinone) — This form is produced by the good bacteria in your large intestine, and it’s also found in some food sources. Menaquinone is the active form and goes to your blood vessels first and then delivers nutrients to your other tissues.
3. Vitamin K3 (menadione) — This is the synthetic form of vitamin K. 

Where to Get Vitamin K

Different food sources use different forms of vitamin K. Plants contain high levels of vitamin K1 and animal sources are high in vitamin K2. Dietary sources rich in vitamin K include:

• Dark, leafy greens: kale, spinach, Brussels sprouts, broccoli, asparagus
• Butter
• Cheese
• Egg yolks
• Meat
• Fermented soybean products

Each form of vitamin K is also available in nutrition supplements. It’s important to do your homework when choosing a nutrition supplement as all forms of vitamin K are not equal. We recommend choosing supplements that use the most effective and bioavailable form of vitamin K, which is K2 delivered through MICROGEL technology. This delivery system allows you to fully absorb nutrients into your bloodstream and then into cells, where they work to improve health.

How Much Vitamin K Do You Need?

Everyone is different, and certain factors such as your age, sex, or health will affect your unique nutritional needs differently than someone else. To provide a general guide, adequate intake (AI) levels were established to meet the needs of most healthy individuals.

The recommended AI for vitamin K is as follows: [5]

• Infants (0 – 12 months): 2–2.5 mcg/day
• Children (1 – 8 years): 30–55 mcg/day
• Adolescents (9 – 18 years): 60–75 mcg/day
• Adults (19+ years): 2.4 mcg/day
• Pregnant and nursing women: 90–120 mcg/day

If you have a preexisting health condition, concern, or take prescription medication, it’s important to talk to your doctor or registered dietitian about your nutrition, especially when choosing which supplements and dosages are optimal for your health.

Can You Take Too Much Vitamin K?

It is very rare to develop vitamin K toxicity, especially for adults. Toxicity is so rare that there is not enough data to establish a tolerable upper intake level (UL). [4][6] A tolerable upper intake level is the maximum daily consumption level that may cause an adverse event. Vitamin K is the only fat-soluble vitamin out of the four (A, D, E, and K) that does not have an upper intake level known to cause toxic side effects.

The only form of vitamin K that has the potential to produce toxic side effects is vitamin K3. In the past, this synthetic form was given as an injection to premature infants to treat vitamin K deficiency. These injections resulted in toxicity and jaundice in some cases. [4][6] Consequently, this form is no longer used to treat deficiency, and instead vitamin K1 is used to treat infant deficiency.

Vitamin K Deficiency — Are You at Risk?

Vitamin K deficiency in adults is rare but not impossible. Symptoms of vitamin K deficiency are:

• Bruising easily
• Unmanageable bleeding
• Hemorrhaging
• Osteoporosis

It is important to note these symptoms can be caused by a number of factors, and one of the ways to rule out this deficiency is to ask your physician to test your nutrient levels with a blood test.

People at risk include:

• Those taking anti-coagulants — You need to carefully control your vitamin K intake when taking blood thinners like warfarin, known by brand names such as Coumadin. Fluctuation in your vitamin K levels can cause dangerous and slower blood clots.
• Those with gastrointestinal or malabsorption disorders — Celiac disease, ulcerative colitis, and short bowel syndrome can hinder absorption. [4][6]
• Those taking antibiotics for long periods of time — It is advised to increase vitamin K intake because antibiotics kill the vitamin K-producing bacteria found in your intestines. [1]
• Infants — Newborns are susceptible to deficiency as their intestines lack the bacteria that produce vitamin K, and there are low amounts of this vitamin in breast milk. Deficient infants risk vitamin K deficiency bleeding (VKDB), which causes uncontrollable internal bleeding. To prevent VKDB, it is suggested that infants get 0.5-1 mg of vitamin K1 injected at birth. [4]

Vitamin K in Healthycell Products

Bioactive MultiBest for absorption!
The form of vitamin K contained in Bioactive Multi is vitamin K2 (menaquinone). The dosage of vitamin K is 120 mcg, which satisfies 100 percent of the Daily Value (%DV).

Healthycell Pro
The form of vitamin K contained in Healthycell Pro is natural vitamin K2 (menaquinone) from natural chickpea extract. The dosage of vitamin K is 40 mcg in the morning formula and 40 mcg in the evening formula, for a daily dosage of 80 mcg, satisfying 100 percent of the Daily Value (%DV).

The form of vitamin K contained in Healthycell is natural vitamin K2 (menaquinone) from natural chickpea extract. The dosage of vitamin K is 40 mcg in the morning formula and 40 mcg in the evening formula, for a daily dosage of 80 mcg, satisfying 100 percent of the Daily Value (%DV).

Conclusions and Recommendations

• Vitamin K plays an important role in blood clotting. It helps prevent excessive bleeding and allows your skin to heal after a cut.
• Both deficiency and toxicity are rare in adults, but deficiency is more common in infants.
• The best form of vitamin K for optimal absorption is vitamin K2 delivered through MICROGEL technology.


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