* Phylloquinone and menaquinones differ in source, absorption rates, tissue distribution, bioavailability, and target activity. Early research suggested that certain menaquinones may be the predominant form of vitamin K found in extra-hepatic tissues and may be affected by diet, gender, and age (Huber et al, 1999). There is ongoing research to highlight and summarizes differences between vitamin K1 and K2 in intake and function, beyond coagulation (Wen et al, 2018; Halder et al, 2019; Simes et al, 2020). This new information will contribute to foster the use of vitamin K as a health-promoting supplement, which may prevent a wide range of disabling diseases (Wei et al, 2019), and which could meet the increasing consumer demand.
* In humans, at least 17 different VKDPs, which are also known as Gla proteins, have been identified to date, and are generally referred to as hepatic and extra-hepatic VKDPs, according to the synthesis location (Willems, Vermeer et al, 2014). The hepatic group of VKDPs synthesized in the liver are essential for regulating blood coagulation and comprise the coagulation factors II, VII, IX, and X, and the anti-coagulation proteins C, S, and Z. Extra-hepatic VKDPs include matrix Gla protein (MGP), osteocalcin (OC), Gla-rich protein (GRP), growth arrest-specific protein 6 (Gas6), proline-rich Gla proteins (PRGP1 and 2), transmembrane Gla proteins (TMG3 and 4), periostin, and the GGCX enzyme. These extra-hepatic VKDPs, which are mostly known for their protective role in the bone and cardiovascular system, exhibit a broad tissue distribution and are involved in a wide range of biological functions such as bone homeostasis, ectopic calcification, cell differentiation and proliferation, inflammation, and signal transduction (Parker et al, 2009; Calvo et al 1996; Schurgers, 2005). The widespread expression of MGP points to its role in maintaining microvascular integrity and preserving the structure and function of vital organs, including the retina (Wei et al, 2018), kidney (Wei et al, 2016; Puzantian et al, 2018) and heart (Willems et al, 2014; Andrews et al, 2018) and bone (Ducy et al, 1996; Levinger et al, 2017).
* Vitamin K2, or menaquinones, have been found to improve mitochondria functioning in cells. Mitochondria are unique structures in the cells of people. They serve as batteries, generating energy and powering the cell and the body. They also synthesize and package proteins for transport to different parts of the cell and beyond, and contribute to neurological functioning. Damaged mitochondria have been implicated in such diseases as Parkinson's Disease, cancer, Alzheimer's Disease, and ALS, a progressive neurological disease that impairs nerve functioning to the muscles. (Schapira, 2006; Alam, et al 2016, Seyfried, 2015; Anandatheerthavarada et al 2003; Devi et al 2006; Manczak et al 2006; Reddy & Beal 2008; Martin et al 2007; Martin et al 2009).