Phylloquinone (Vitamin K)

Vitamin K is a a designation that refers to a group of related lipid soluble compounds that are needed by the body for a variety of functions. Vitamin K is most known for its role in protein biosynthesis, vascular formation/maintenance, blood coagulation, and as a key element in the formation of bones. There are two primary forms of this nutrient; Vitamin K1 (also known as phylloquinone, phytomenadione, and/or phytonadione) and Vitamin K2 (also known as menaquinone and/or menatetrenone). Vitamin K1 is normally attained through diet or supplementation, while vitamin K2 is normally produced by bacteria in the large intestine, so deficiency is quite rare unless there is a problem with the intestines or prolonged antibiotic use. There are also three synthetic forms of vitamin K (vitamins K3, K4, and K5), which will not be discussed here since they are not used in supplements or skincare products.

Vitamin K1 is found readily in leafy green vegetables such as swiss chard, spinach, cabbage, parsley, kale, cauliflower, broccoli, and brussels sprouts. Some fruits, such as avocado and kiwi, are also high in vitamin K1 content. Vitamin K1 is, however, very tightly bound to chlorophyll in green vegetables so so their bioavailability is relatively low unless served with oil added (which roughly doubles the ability of the body to absorb vitamin K1 during a meal). Vitamin K2 is found in meat, eggs, and dairy since it’s primarily synthesized by animal tissues, but as previously mentioned the colon bacteria in humans creates the majority of the vitamin K2 that humans need.

Vitamin K is a very important, though often overlooked, ingredient in skincare formulations as it plays an influential role in the healing of bruising as well as the proper functioning of blood vessels and capillaries. This makes it important for varicose vein treatment as well as the repair of broken capillaries (spider veins) that show through the skin’s surface (a condition common in the skin as years progress, being especially prominent in those that have rosacea and eczema). It is also very beneficial ingredient for alleviating the appearance of undereye dark circles. In fact, it is one of the leading ingredients for dark circle alleviation and functions well in oil-water emulsions when applied under the eyes (it is less effective when included in aqueous serums because vitamin K being lipid soluble needs a certain amount of oil to adequate absorb into the skin).