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Vladimir Eliseev
Vladimir Eliseev

Where Can I Buy Vitamin K2

What you may not know is that vitamin K is actually a name given to a class of vitamins. What we commonly think of as vitamin K includes vitamin K1 (also called phylloquinone), as well as vitamin K2 (menaquinone). They work differently in your body and come from different food sources.

where can i buy vitamin k2

Vitamin K1 comes from plant sources, like leafy greens and blueberries. While vitamin K2 is more common in animal products, fermented foods and some kinds of cheese. It stays in your body longer than vitamin K1 and holds the potential for some serious health benefits that are just now starting to come to light.

Other research showed that women and people assigned female at birth (AFAB) who had a high intake of vitamin K2-rich foods (but not vitamin K1) were less likely to experience cardiovascular events, like heart attacks and strokes. For every 10 micrograms of vitamin K2 they consumed per day, their risk of heart disease decreased by 9%.

While we may think of vitamin K as one vitamin, it actually is a category made up of vitamin K1 (also called phylloquinone) and vitamin K2 (also known as menaquinone). Both are believed to have similar body-boosting effects.

Currently, the U.S. Department of Agriculture (USDA) lists the vitamin K values of foods mostly based on their vitamin K1 content. More research needs to be done to create a more comprehensive understanding of vitamin K2 in various foods.

Zumpano walks us through foods that are presently thought to have the highest concentrations of vitamin K2 and recommendations for which ones are the best (and worst) choices for your overall health.

In the meantime, getting your fill of vitamin K1 through leafy greens and the like is a sure bet to meet the USDA guidelines for vitamin K. And if you mix in some vitamin K2-rich foods, stick to the healthier choices, like nattō, chicken breast and sauerkraut.

Objective: To investigate whether vitamin K2 supplementation plays a role in maintaining bone mineral density (BMD) and reducing the incidence of fractures for postmenopausal women with osteoporosis at a long-term follow-up.

Materials and methods: We searched systematically throughout the databases of PubMed, Cochrane library, and EMBASE from the dates of their inception to November 16 2021 in this meta-analysis and systematic review, using keywords vitamin K2 and osteoporosis.

Results: Nine RCTs with 6853 participants met the inclusion criteria. Vitamin K2 was associated with a significantly increased percentage change of lumbar BMD and forearm BMD (WMD 2.17, 95% CI [1.59-2.76] and WMD 1.57, 95% CI [1.15-1.99]). There were significant differences in undercarboxylated osteocalcin (uc-OC) reduction (WMD -0.96, 95% CI [-0.70 to 0.21]) and osteocalcin (OC) increment (WMD 26.52, 95% CI [17.06-35.98]). Adverse reaction analysis showed that there seemed to be higher adverse reaction rates in the vitamin K2 group (RR = 1.33, 95% CI [1.11-1.59]), but no serious adverse events related to vitamin K2 supplementation.

Conclusion: This meta-analysis and systematic review seemed to support the hypothesis that vitamin K2 plays an important role in the maintenance and improvement of BMD, and it decreases uc-OC and increases OC significantly at a long-term follow-up. Vitamin K2 supplementation is beneficial and safe in the treatment of osteoporosis for postmenopausal women.

Vitamin K2 (menaquinone, MK-n) is a lipid-soluble vitamin that functions as a carboxylase co-factor for maturation of proteins involved in many vital physiological processes in humans. Notably, long-chain vitamin K2 is produced by bacteria, including some species and strains belonging to the group of lactic acid bacteria (LAB) that play important roles in food fermentation processes. This study was performed to gain insights into the natural long-chain vitamin K2 production capacity of LAB and the factors influencing vitamin K2 production during cultivation, providing a basis for biotechnological production of vitamin K2 and in situ fortification of this vitamin in food products.

We observed that six selected Lactococcus lactis strains produced MK-5 to MK-10, with MK-8 and MK-9 as the major MK variant. Significant diversities between strains were observed in terms of specific concentrations and titres of vitamin K2. L. lactis ssp. cremoris MG1363 was selected for more detailed studies of the impact of selected carbon sources tested under different growth conditions [i.e. static fermentation (oxygen absent, heme absent); aerobic fermentation (oxygen present, heme absent) and aerobic respiration (oxygen present, heme present)] on vitamin K2 production in M17 media. Aerobic fermentation with fructose as a carbon source resulted in the highest specific concentration of vitamin K2: 3.7-fold increase compared to static fermentation with glucose, whereas aerobic respiration with trehalose resulted in the highest titre: 5.2-fold increase compared to static fermentation with glucose. When the same strain was applied to quark fermentation, we consistently observed that altered carbon source (fructose) and aerobic cultivation of the pre-culture resulted in efficient vitamin K2 fortification in the quark product.

With this study we demonstrate that certain LAB strains can be employed for efficient production of long-chain vitamin K2. Strain selection and optimisation of growth conditions offer a viable strategy towards natural vitamin K2 enrichment of fermented foods, and to improved biotechnological vitamin K2 production processes.

Vitamin K is a fat-soluble vitamin that is essential for human health [1]. It functions as an enzyme cofactor for γ-carboxylation of glutamate (Gla) residues in Gla-proteins, which play key roles in a number of vital physiological processes including haemostasis, calcium and bone metabolism, as well as cell growth regulation [1, 2]. Vitamin K exists naturally in two forms: vitamin K1 (phylloquinone) and vitamin K2 (menaquinones). Vitamin K1 is abundantly present in green leafy vegetables and found in some vegetable oils and is the predominant form of vitamin K in our daily diet. Vitamin K2 refers to a group of menaquinones (MKs) varying in side chain length. Different forms of MKs are written as MK-n, where n indicates the number of isoprenoid residues in its side chain [3]. MK-4 is the most common form of short-chain MKs, and is produced in human and animal tissues by converting vitamin K1 or analogs of MK-precursors [3]. Meats, eggs and milk are the common dietary source of MK-4. The long-chain MKs, namely MK-5 to MK-13, are uniquely synthesized by bacteria [3]. The main dietary sources of long-chain MKs are fermented foods [3, 4].

The dietary intake of vitamin K2 covers only 10% to 25% of the total vitamin K intake in the Dutch and German population [5] and is assumed to be even lower in many other countries. The bioavailability of vitamin K2 is thought to be higher than that of vitamin K1 [6]. Compared to vitamin K1, the co-factor efficacy of vitamin K2 for protein carboxylation has been shown to be higher [7]. Notably, some forms of vitamin K2 with long side chains, e.g. MK-7 and MK-9, have been found to have longer plasma half-life times than vitamin K1 and MK-4, suggesting advantages for their uptake and utilization by the human body [7,8,9]. Moreover, indications have been found that dietary intake of vitamin K2, especially in the form of MK-7, MK-8 and MK-9, is associated with a reduced risk of coronary heart disease [6, 10, 11]. Vitamin K2 intake is also involved in normal bone growth and development, whereas its deficiency is associated with increased risk of fracture and low bone mineral density [2, 5, 12, 13]. Some intestinal bacteria also produce vitamin K2, but in animal studies the absorption of this vitamin in the colon was found to be limited [14] and hence dietary intake is an essential source to obtain this vitamin. This information, combined with advances in nutrition research, underline the importance of fortifying food products with vitamin K2, especially the long-chain forms, in food products and supplements.

Production of long-chain vitamin K2 has been observed in a variety of bacteria involved in well-known food fermentation processes, and the specific structure of menaquinones produced by these bacteria has been determined [3, 15]. These food grade bacteria can be seen as potential candidates for in situ fortification in fermented foods and biotechnological production of long-chain MKs. Bacillus subtilis produces MK-7 and some strains are used to make fermented soybean food products, among which the Japanese natto is well-known [3]. However, fermented food products involving B. subtilis are mostly appreciated in certain regions in Asia and do not contribute to the western diet. Several studies have been performed to optimize biotechnological production of MK-7 in B. subtilis [16,17,18]. Propionibacteria, producing MK-9 (4H), are used to produce Swiss-type cheeses [19, 20] and are applied in biotechnological MK-9 (4H) production processes [21]. Lactic acid bacteria (LAB) are key players in various food fermentation processes as starter cultures, probiotics and producers of vitamins. Among LAB, Lactococcus lactis ssp. cremoris, L. lactis ssp. lactis, Leuconostoc lactis and Leuconostoc mesenteroides are the reported producers of mainly MK-8, MK-9 and MK-10 [22]. In spite of the wide applications of LAB, studies were mainly conducted to reveal vitamin K2 levels in fermented dairy products [4, 19] and only a few studies [22, 23] collected information on vitamin K2 production in LAB in laboratory conditions. Therefore, long-chain vitamin K2 production in LAB definitely deserves more investigation.

Vitamin K2 is present in the cytoplasmic membranes of producing bacteria, acting as an electron carrier in the respiratory electron transport chain (ETC) [24]. Although LAB have been classified as non-respiring, facultative anaerobes, conclusive evidence has been found for functional respiration in various lactococci, lactobacilli, and pediococci in response to heme (for some species, menaquinone and heme) supplementation [23]. Menaquinones, together with the NADH dehydrogenase complex and the bd-type cytochrome complex (where heme functions as an essential cofactor), form a simple electron transport chain that enables aerobic respiration in these bacteria when oxygen is present. Nevertheless, it was found that menaquinone is produced in L. lactis continuously, under conditions including static fermentation (no oxygen or heme present), aerobic fermentation (oxygen present, no heme) and aerobic respiration (both oxygen and heme present) [23]. The role of menaquinones in the fermentative metabolism of producing bacteria remains unclear so far. 041b061a72


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