Vitamin K refers to a group of compounds that share a similar chemical structure, playing a crucial role in various bodily functions.

Among these is Vitamin K3, commonly referred to as menadione, which is a synthetic form of vitamin K, created through artificial processes.

This article will delve into the essential aspects of vitamin K3, covering its numerous benefits, practical applications, and any potential side effects you should be aware of.

Understanding Vitamin K3

Vitamin K plays a crucial role in promoting healthy blood clotting and maintaining strong bones. Additionally, it has the potential to prevent harmful accumulation of calcium in the tissues, organs, and blood vessels, particularly in individuals who are at risk for certain health issues such as kidney disease, cardiovascular diseases, and diabetes. Vitamin K3, known scientifically as menadione, is a synthetic derivative of vitamin K that does not naturally occur in foods. This distinguishes it from the other two naturally occurring forms of vitamin K: vitamin K1 (phylloquinone), primarily found in leafy green vegetables, and vitamin K2 (menaquinone), which is prevalent in fermented foods and animal products.

Interestingly, the liver has the capability to convert vitamin K3 into the more active form, vitamin K2. Many animals also possess the ability to transform vitamin K3 into the active forms of vitamin K, thereby utilizing it efficiently. Although vitamin K3 is not available as a dietary supplement for humans due to safety regulations, it finds extensive application in the agriculture sector, particularly in poultry and pig feed, as well as in commercial pet food for dogs and cats, ensuring proper nutrition for livestock and pets alike.

In summary, while vitamin K3 serves a significant role in animal health and nutrition, it is not intended for human dietary supplementation.

Harmful Effects on Humans

Extensive research conducted during the 1980s and 1990s has revealed that vitamin K3 can be detrimental to human health. Findings from these studies have established a connection between vitamin K3 and adverse effects such as liver damage and the destruction of oxygen-carrying red blood cells. Consequently, only the natural forms, K1 and K2, are permitted as dietary supplements and in prescriptions.

Interestingly, despite its harmful implications for humans, vitamin K3 does not seem to pose risks to livestock or pets when incorporated into feed at regulated levels. However, this has sparked a debate regarding the inclusion of K3 in pet food formulations, with some companies that exclude it promoting their products as superior to those that include this controversial ingredient.

Regardless of the ongoing discussions, it's important to note that the naturally occurring forms of vitamin K—K1 and K2—exhibit a minimal potential for toxicity in humans. This low toxicity profile has led organizations like the National Academy of Sciences and the European Food Safety Authority (EFSA) to refrain from setting an upper intake limit for vitamin K. An upper limit refers to the maximum quantity of a nutrient that can be consumed without posing significant harm to the majority of individuals.

In summary, while vitamin K3 is recognized as harmful to humans, the natural variants, K1 and K2, are deemed safe with a low risk of toxicity.

Potential Anticancer and Antibacterial Properties

While vitamin K3 has some notorious adverse effects in humans, intriguing studies have revealed its potential anticancer and anti-inflammatory capabilities when examined in vitro. For instance, research has demonstrated that this vitamin may effectively eliminate human breast, colorectal, and kidney cancer cells by activating a specific class of proteins. Additionally, vitamin K3 has been linked to enhanced production of reactive oxygen species, which are molecules that possess the capacity to damage or even destroy cancer cells.

Moreover, some in vitro studies suggest that when combined with vitamin C, vitamin K3 may work synergistically to inhibit the proliferation of human breast and prostate cancer cells, amplifying its anticancer effects. Beyond its cancer-fighting potential, there are indications that vitamin K3 may also exhibit antibacterial properties, which is particularly relevant in today's world where antibiotic resistance is a growing concern.

One notable study demonstrated that vitamin K3 can suppress the growth of Helicobacter pylori, a detrimental bacterium that resides in the digestive tract, by diminishing the bacterium's capacity to replicate within infected human stomach cells. Despite these promising findings, it is crucial to emphasize that further research is warranted before any definitive claims can be made regarding the safety and efficacy of vitamin K3 in treating cancer or other medical conditions in humans. Additionally, given the potential harm that vitamin K3 may cause in human subjects, any future investigations will need to thoroughly evaluate whether the prospective benefits of this vitamin for treating various conditions justify the associated risks.

In summary, while vitamin K3 has exhibited anticancer and antibacterial properties in laboratory settings, these advantageous effects have yet to be confirmed through clinical studies in humans.

What is the Recommended Daily Intake of Vitamin K?

The National Academy of Sciences suggests that adult women aim for an intake of 90 mcg of vitamin K daily, while men are advised to consume 120 mcg. In contrast, the European Food Safety Authority (EFSA) recommends a lower intake of just 70 mcg for adults or approximately 0.5 mcg per pound (1 mcg per kg) of body weight each day. These guidelines are established to prevent deficiency symptoms such as excessive bleeding. However, further studies are necessary to ascertain the optimal level of vitamin K for enhancing bone health and reducing vascular calcification. Since vitamin K is present in a wide range of foods, most individuals can easily acquire sufficient amounts through their dietary choices.

Natural Dietary Sources of Vitamin K

Vitamin K1 is predominantly found in an array of green leafy vegetables, such as collards (sarson da saag), spinach (palak), kale (kale), and broccoli (hari gobhi), as well as in vegetable oils like soybean and canola oil. Additionally, certain fruits, including blueberries (neelbadri) and grapes, also contribute to vitamin K intake. On the other hand, vitamin K2 is primarily sourced from fermented foods like sauerkraut and natto — a traditional Japanese dish made from fermented soybeans — but can also be found in poultry and pork products. This form is also synthesized by beneficial bacteria within the gut.

Excellent sources of vitamin K include:

• 85 grams of natto: 708% of the Daily Value (DV)
• 18 grams of collards: 442% of the DV
• 45 grams of turnip greens: 335% of the DV
• 28 grams of spinach: 121% of the DV
• 21 grams of kale: 94% of the DV
• 44 grams of broccoli: 92% of the DV
• 14 mL of soybean oil: 21% of the DV
• 175 mL of pomegranate juice: 16% of the DV
• 70 grams of blueberries: 12% of the DV
• 84 grams of chicken breast: 11% of the DV
• 35 grams of lettuce: 12% of the DV

The absorption rate of vitamin K varies depending on its source. For instance, the vitamin K found in green leafy vegetables is closely linked to cellular structures known as chloroplasts, making it more challenging for the body to absorb compared to vitamin K sourced from oils or dietary supplements. Nevertheless, green leafy vegetables remain the primary source of vitamin K in diets across many cultures, including those in Australia and Canada. To enhance the absorption of vitamin K from these vegetables, consider pairing them with healthy fats such as oils, nuts, or avocado.

It is crucial to consult with your healthcare provider before starting vitamin K supplements or significantly increasing your intake of vitamin K-rich foods, particularly if you are on blood-thinning medications like Warfarin or Coumadin, as vitamin K can affect their efficacy. However, it is not necessary to completely avoid vitamin K-rich foods; rather, maintaining a consistent intake is advisable.

In summary, the majority of individuals can meet their vitamin K requirements through a well-rounded diet, with green leafy vegetables and certain fermented foods like natto being the most beneficial sources.

The Bottom Line

Vitamin K is crucial for various bodily functions, including blood clotting, promoting strong bones, and regulating healthy calcium levels in the bloodstream. Among its forms, Vitamin K3 is a synthetic variant, whereas vitamins K1 and K2 are naturally occurring in foods. While vitamin K3 has shown potential anticancer and antibacterial effects in laboratory tests, it has been linked to negative health effects in humans. Consequently, it is not available for sale as a dietary supplement nor prescribed, unlike its natural counterparts, vitamins K1 and K2. Fortunately, the majority of individuals obtain sufficient amounts of vitamin K through their regular diets, rendering supplementation largely unnecessary.