Vitamin K is named after the German word koagultion because of its important role in encouraging normal blood clotting after an injury. Vitamin K also plays a far more diverse role. It increases bone mineral density, which is crucial in preventing osteoporosis, and reduces the mortality risk and recurrence of liver cancer. There is also promising evidence to suggest that Vitamin K may limit insulin resistance, improve insulin sensitivity and improve physical performance.
Our form of Vitamin K2 (from Natto) is Vitamin K in its most biologically active form. Vitamin K2 has superior absorption and retention in the body compared to Vitamin K1, which is the form typically found in supplements.
Product Type: 1 Veggie Capsule Dosage: 120mg |
Hydroxypropyl Methylcellulose (Vegetarian Capsule), Microcrystalline Cellulose (Plant Fiber)
milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans, artificial colours or preservatives
Studies show that Vitamin K reduces clinical fractures in women[1] and also reduces the risk of bone cancer.[2] There appears to be a relative increase in bone mineral density associated with Vitamin K supplementation because it decreases the rate of bone loss. However, it should be noted that this increase is small compared to more intrusive medical procedures like estrogen replacement therapy, although it is statistically significant.[3] [4]
Illustrative Studies
Over 200 postmenopausal women were given Vitamin K2 or a placebo for three years, and their bone strength and density was measured each year. Vitamin K2 supplementation showed a reduced age-related decline in bone mineral content and bone mineral density at the lumbar spine and femoral neck, but not at the total hip. Vitamin K2 increased overall bone strength and decreased the loss of vertebral height in the lower thoracic region (part of the back above the hip).[5]
In another study, blood samples were taken from two groups, people who had osteoporosis and just experienced a fracture and those who did not have osteoporosis and were otherwise healthy. Vitamin K2 levels were significantly higher in the group without osteoporosis. In the osteoporosis group, less than 10% were getting sufficient levels of Vitamin K2.[6]
Research Score: Very Strong
Vitamin K promotes normal blood clotting.[7] Studies have suggested there is an inverse relationship between Vitamin K levels in the blood and risks of heart disease, especially in people with high blood pressure.[8] MGP, the most common Vitamin K dependent protein,[9] is the main protein in a small network of proteins that helps remove calcium from the arterial wall. This reduces the risk of all cause mortality (any cause of death brought on by disease or harmful exposure) and arterial stiffness. Vitamin K2 also supports the production of Gla-protein, another protein that prevents calcification of the arteries and soft-tissue.
Studies additionally show that Vitamin K is negatively correlated with calcium progression in people with high blood pressure.
Illustrative Studies
Over 16,000 women who were free of cardiovascular disease recorded their diets in a food frequency questionnaire. Over the next 8 years, 15,500 women did not develop cardiovascular heart disease (CHD), but 480 did. In the 480 cases of CHD, the average daily Vitamin K2 intake for the patients who developed CHD was 29.1mcg, far below the recommended daily intake of 80mcg/day.[10]
A 2004 study reviewed Vitamin K2 intake and its relation to CHD in over 4,800 people. It found the risk of CHD mortality and severe aortic calcification (calcification of the aorta in the heart) was reduced in the middle and upper tiers of Vitamin K2 consumption when compared to the lower tier.[11]
Further, a 2015 clinical study attempted to prove a link between Vitamin K2 and arterial stiffness, a major contributor to heart attack and stroke. 244 healthy post-menopausal women were randomized and given
either a placebo or 180mcg of Vitamin K2 per day. After three years, the group taking Vitamin K2 showed fewer signs of arterial stiffness than the placebo group.[12]
Research Score: Strong
Vitamin K supplementation has been shown to potentially reduce mortality and recurrence risk of liver cancer.
Two studies examined the effect of taking 45 mg of Vitamin K per day for patients with liver cirrhosis. Results showed Vitamin K inhibited cancer-cell growth and improved overall survival.[13] [14] Although the studies have used super loading of Vitamin K (40mg or more) and only in relation to liver cancer, the reduction in mortality risk and prolongation of survival times is notable.[15] Recurrence rates of hepatocellular carcinoma (the most common form of liver cancer) appears to be significantly less than placebo when using Vitamin K in a super loading scheme (40mg or more daily).[16]
Research Score: Promising
A 2008 study showed Vitamin K supplementation reduced the risk of type 2 diabetes. Participants with insulin resistance were given 500 micrograms of Vitamin K for 36 months. Results showed Vitamin K reduced the progression of insulin resistance.[17] Higher levels of total osteocalcin (a Vitamin K dependent protein) and a higher rate of carboxylation (indicative of a better Vitamin K status) appear to lead to better insulin sensitivity in overweight persons,[18] older individuals,[19] [20] [21] [22] and physically active persons.[23] Therefore, it is highly likely that supplementing Vitamin K will be effective in improving insulin sensitivity, although there needs to be further studies specifically on the effects of supplementing Vitamin K.[24]
Research Score: Promising
A 2017 study examined active individuals who supplemented 300 mg Vitamin K every day for eight weeks. After multiple physical tests, results show Vitamin K may increase exercise performance in active groups of people especially athletes.[25]
Research Score: Promising
1.
Cheung AM, Tile L, Lee Y, et al. Vitamin K supplementation in postmenopausal women with osteopenia (ECKO trial): a randomized controlled trial. PLoS Med. 2008;5(10):e196.
2.
Maresz K. Proper Calcium Use: Vitamin K2 as a Promoter of Bone and Cardiovascular Health. Integrative Medicine: A Clinician’s Journal. 2015;14(1):34-39.
3.
4.
5.
Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Knapen MH, Drummen NE, Smit E, Vermeer C, Theuwissen E., Osteoporosis International, 2013
6.
Depressed levels of circulating menaquinones in patients with osteoporotic fractures of the spine and femoral neck. Hodges SJ, Pilkington MJ, Stamp TC, Catterall A, Shearer MJ, Bitensky L, Chayen J., Bone, 1991
7.
8.
Shea MK, Booth SL, Weiner DE, et al. Circulating Vitamin K Is Inversely Associated with Incident Cardiovascular Disease Risk among Those Treated for Hypertension in the Health, Aging, and Body Composition Study (Health ABC). The Journal of Nutrition. 2017;147(5):888-895. doi:10.3945/jn.117.249375
9.
10.
A high menaquinone intake reduces the incidence of coronary heart disease.
Gast GC, de Roos NM, Sluijs I, Bots ML, Beulens JW, Geleijnse JM, Witteman JC, Grobbee DE, Peeters PH, van der Schouw YT., Nutrition, metabolism and cardiovascular diseases: NMCD, 2009
11.
"Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomised clinical trial." Knapen MH, Braam LA, Drummen NE, Bekers O, Hoeks AP, Vermeer C., Thrombosis and haemostasis, 2015
12.
Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. Geleijnse JM, Vermeer C, Grobbee DE, Schurgers LJ, Knapen MH, van der Meer IM, Hofman A, Witteman JC., The Journal of Nutrition, 2004
13.
Habu D, Shiomi S, Tamori A, et al. Role of vitamin K2 in the development of hepatocellular carcinoma in women with viral cirrhosis of the liver. JAMA. 2004;292(3):358-61.
14.
Kakizaki S, Sohara N, Sato K, et al. Preventive effects of vitamin K on recurrent disease in patients with hepatocellular carcinoma arising from hepatitis C viral infection. J Gastroenterol Hepatol. 2007;22(4):518-22.
15.
16.
17.
Yoshida M, Jacques PF, Meigs JB, et al. Effect of Vitamin K Supplementation on Insulin Resistance in Older Men and Women . Diabetes Care. 2008;31(11):2092-2096. doi:10.2337/dc08-1204.
18.
BA, et al. Associations of total and undercarboxylated osteocalcin with peripheral and hepatic insulin sensitivity and β-cell function in overweight adults . J Clin Endocrinol Metab. (2013)
19.
Shea MK, et al. Gamma-carboxylation of osteocalcin and insulin resistance in older men and women . Am J Clin Nutr. (2009)
20.
Pittas AG, et al. Association between serum osteocalcin and markers of metabolic phenotype . J Clin Endocrinol Metab. (2009)
21.
Kindblom JM, et al. Plasma osteocalcin is inversely related to fat mass and plasma glucose in elderly Swedish men . J Bone Miner Res. (2009)
22.
Im JA, et al. Relationship between osteocalcin and glucose metabolism in postmenopausal women . Clin Chim Acta. (2008)
23.
Fernández-Real JM, et al. The relationship of serum osteocalcin concentration to insulin secretion, sensitivity, and disposal with hypocaloric diet and resistance training . J Clin Endocrinol Metab. (2009)
24.
25.
Mcfarlin BK, Henning AL, Venable AS. Oral Consumption of Vitamin K2 for 8 Weeks Associated With Increased Maximal Cardiac Output During Exercise. Altern Ther Health Med. 2017;23(4):26-32.