What is another name for phylloquinone?

December 17, 2025 •

3 min read

Phylloquinone is a fat-soluble vitamin found abundantly in plants, especially leafy green vegetables like spinach and kale. But this essential nutrient goes by a few other names that are important to recognize in nutrition and medical contexts. To clarify, what is another name for phylloquinone? The most common alternative names are Vitamin K1 and phytonadione.

Quick Summary

Phylloquinone, also known as Vitamin K1 or phytonadione, is a fat-soluble vitamin predominantly found in green, leafy vegetables that is crucial for blood clotting and bone metabolism. This article explores the different names for this vitamin and its key biological functions.

Key Points

Alternative Names: Phylloquinone is also known as Vitamin K1 or phytonadione.
Context is Key: While Vitamin K1 is used in a nutritional context, phytonadione is the medical/pharmaceutical term.
Crucial for Clotting: Phylloquinone plays a vital role in blood coagulation by helping the liver synthesize key clotting factors.
Supports Bone Health: This vitamin is also essential for bone metabolism, activating a protein that helps mineralize bones.
Difference from K2: Phylloquinone (K1) is distinct from menaquinone (K2), which is produced by bacteria and has a different set of effects related to bone and cardiovascular health.
Found in Leafy Greens: The primary dietary sources of phylloquinone are green leafy vegetables like spinach and kale.
Bioavailability: Vitamin K1 from leafy greens is less bioavailable than that found in supplements or oils, and its absorption is enhanced by fat.

Unpacking the Different Names for Phylloquinone

Phylloquinone is the technical chemical term for Vitamin K1. The different names—phylloquinone, Vitamin K1, and phytonadione—often cause confusion, but they all refer to the same essential nutrient, though they may highlight different aspects of its identity. Understanding these distinctions can be helpful when reading nutritional labels, medical reports, or scientific studies.

Vitamin K1: The Dietary Standard

In a nutritional context, Vitamin K1 is the most widely used and recognized name for phylloquinone. This is the form of the vitamin that humans primarily obtain from plant-based foods. It is common to see 'Vitamin K' mentioned in discussions of general health and diet, but it's important to remember that this term refers to a family of compounds, with K1 being just one part.

Phytonadione: The Medical Moniker

When encountered in a medical or pharmaceutical setting, phylloquinone is frequently referred to as phytonadione. This term is used for the synthetic version of Vitamin K1 used in supplements and medications. Phytonadione is clinically administered to treat conditions like Vitamin K deficiency, hemorrhagic conditions in infants, or to reverse the effects of certain blood-thinning medications. The name itself combines phyto (from plants) and nadione (referring to the chemical structure, a naphthoquinone).

Other Technical and Chemical Synonyms

Beyond the most common names, several other scientific and chemical terms also refer to phylloquinone. These names are generally reserved for highly technical or academic discussions but can sometimes appear in specialized materials. They include:

2-Methyl-3-phytyl-1,4-naphthoquinone
3-Phytylmenadione
Alpha-phylloquinone
Phyllochinon

The Function of Phylloquinone (Vitamin K1)

Phylloquinone is not just a nutrient with multiple names; it is a critical cofactor for several bodily functions. Its most well-known role is in blood coagulation. The name 'K' itself comes from the German word for coagulation, Koagulation. It is necessary for the liver to synthesize four of the 13 proteins required for blood clotting. In addition to this, it is essential for bone metabolism by activating a protein called osteocalcin, which helps bind calcium to the bone matrix.

Phylloquinone vs. Menaquinone: A Crucial Comparison

While phylloquinone (Vitamin K1) is the most prominent form in the diet, it is important to differentiate it from menaquinones (Vitamin K2). Both are types of Vitamin K but have different sources and physiological actions in the body. The primary difference lies in their bioavailability and function.

Comparison Table: Phylloquinone (K1) vs. Menaquinone (K2)


Feature	Phylloquinone (Vitamin K1)	Menaquinone (Vitamin K2)
Primary Source	Green leafy vegetables (spinach, kale, collards) and some plant oils (canola, soy).	Animal products (meats, eggs, cheeses) and fermented foods (natto).
Origin	Exclusively synthesized by plants and green algae.	Produced by bacteria, including gut microbiota.
Major Function	Primary role in activating blood clotting factors in the liver.	Longer half-life and greater focus on activating proteins involved in bone and cardiovascular health.
Absorption and Half-Life	Lower bioavailability and shorter half-life (approx. 1-2 hours).	Higher bioavailability and much longer half-life (approx. 72 hours for MK-7).
Transport	Associated with triglyceride-rich lipoproteins (TRLs).	Associated with low-density lipoprotein (LDL), potentially allowing for better transport to extra-hepatic tissues like bone.

Why Knowing the Names Matters

Understanding that phylloquinone, Vitamin K1, and phytonadione refer to the same compound can help you navigate different health contexts. For instance, a doctor discussing Vitamin K deficiency or an overdose of a blood thinner will likely use the term phytonadione, referring to the medical treatment. A nutritionist or health article about dietary sources will likely use the term Vitamin K1. Knowing the interchangeability of these names ensures clarity and accuracy in communication about this essential micronutrient. Furthermore, distinguishing between K1 and K2 is critical for a nuanced understanding of how each contributes uniquely to different physiological processes.

Conclusion

In summary, the answer to "what is another name for phylloquinone?" is multifaceted, with the most common and accurate alternatives being Vitamin K1 and phytonadione. While these terms all describe the same plant-derived compound crucial for blood clotting and bone metabolism, their usage varies depending on the context—nutritional versus medical. Gaining a deeper understanding of these different names and the functions of the various forms of Vitamin K allows for more informed health decisions.

Visit the NIH Office of Dietary Supplements website for comprehensive information on Vitamin K.

Frequently Asked Questions

The primary function of phylloquinone (Vitamin K1) is to serve as an essential cofactor for blood coagulation. It helps the liver produce clotting factors necessary to stop bleeding.

Yes, phytonadione is the medical and pharmaceutical term for phylloquinone, particularly referring to the synthetic version used in supplements and for clinical treatments.

Excellent food sources of phylloquinone include green leafy vegetables like kale, spinach, and collard greens, as well as plant oils such as soybean and canola oil.

The main differences are their sources, half-life, and primary functions. K1 comes from plants and primarily aids blood clotting, while K2 is bacterial in origin (from fermented foods and animal products) and more involved in bone and cardiovascular health.

As a fat-soluble vitamin, phylloquinone requires dietary fat for optimal absorption in the body. This is why eating leafy greens with a source of healthy fat, like olive oil in a salad dressing, can improve its uptake.

Newborn infants have low levels of Vitamin K because of poor placental transfer and sterile guts, which can cause a condition called Vitamin K deficiency bleeding (VKDB). A single injection is standard practice to prevent this.

It is extremely rare to consume too much phylloquinone from food, and no tolerable upper limit has been set. However, those on blood-thinning medications like warfarin must carefully monitor their intake as it can counteract the medication's effects.