With the aging of the population and changes in lifestyle, bone diseases such as osteoporosis have become a global health problem. According to the latest data released by the International Osteoporosis Foundation (IOF), one person suffers a fracture every three seconds, and nearly nine million people suffer osteoporotic fractures every year. One-third of women and one-fifth of men will suffer a fracture after the age of 50 [1]. Fractures not only affect the physical health of patients, but also bring huge economic burdens to families, society and the country. Therefore, the prevention and treatment of osteoporosis has become an important part of national health awareness and action.

In addition to traditional methods such as exercise, calcium supplementation, and sunlight exposure, vitamin K also plays a vital role in bone health. A large number of clinical and epidemiological studies have shown that vitamin K2 is an essential substance for human bone and calcium metabolism, and plays a key and fundamental role in bone and calcium metabolism, which should be taken seriously by osteoporosis patients.

What is Vitamin K?

Vitamin K is a fat-soluble vitamin and an important factor in the coagulation process. It mainly includes vitamin K1 and vitamin K2, both of which are essential biologically active substances for the human body. Vitamin K1 is used to treat and prevent hypocoagulopathy (coagulation factor deficiency) and bleeding diseases. Vitamin K2 has health effects such as activating osteocalcin, promoting energy release, treating osteoporosis, and preventing arteriosclerosis and organ calcification.

How to support bone health?

Vitamin K2 helps bone health mainly by promoting the activation of osteocalcin, increasing the activity of osteoblasts, and inhibiting the activity of osteoclasts. In addition, vitamin K2 also has an immunomodulatory effect and can inhibit the proliferation of T cells.

✦ Osteoblasts are the creators of bones and produce a protein called osteocalcin. Osteocalcin is first activated by vitamin K2 to bind bone and calcium. Calcium is important for maintaining bone health and preventing osteoporosis and fractures.

✦ Vitamin K2 acts like a "light switch finger" and is key to activating osteocalcin. Without enough vitamin K2, osteocalcin cannot bring calcium ions to where they are needed and attach.

✦ Vitamin K2 can participate in bone metabolism, promote the synthesis of osteoblasts, and inhibit the production of osteoclasts, thereby promoting bone formation and reducing bone catabolism. Some studies have explored the effects of vitamin K supplementation on bone density and fractures. A systematic review and meta-analysis of a series of randomized controlled trials conducted in Japan showed that supplementation with phytomenadione or MK-4 (a form of vitamin K2) can improve bone density and significantly reduce the incidence of hip fractures, vertebral fractures, and all non-vertebral fractures [2].

Additionally, a clinical trial in postmenopausal women found that supplementation with MK-7 (a form of vitamin K2) improved lower thoracic vertebrae bone strength and reduced vertebral height loss [3].

Although other randomized clinical trials have found no significant effect of vitamin K supplementation on bone mineral density in older men or women, one of these studies also observed that it is important to consider the effects of both vitamin D and calcium when comparing the results of studies on vitamin K supplementation [4-5].

In Japan and other parts of Asia, pharmacological doses of MK-4 (45 mg) are used as a treatment for osteoporosis.[6] The European Food Safety Authority has approved a health claim for vitamin K, stating that there is a causal relationship between dietary intake of vitamin K and the maintenance of normal bones.[7]

Therefore, in summary, in order to support bone health, in addition to adequate calcium and vitamin D3, supplementing with sufficient vitamin K2 is the basic guarantee for maintaining bone and overall body health.

How to supplement vitamin K?

Vitamin K1 is mainly found in green vegetables and plant chlorophyll, including spinach, cabbage, kale, etc., as well as fruits such as avocado and kiwi; Vitamin K2 comes from fermented foods, meat, dairy products and intestinal bacteria. Currently, the best food source of vitamin K2 is natto, and the content in other foods is very small.

Due to the low content of vitamin K2 in food, it is difficult for people to get enough vitamin K2 from their daily diet, so taking vitamin K2 nutrient supplements appropriately is also an important way.

How much vitamin K2 should be supplemented? According to the AI ​​of 80 μg/d for dietary vitamin K for adults determined by China [9], you can refer to this recommendation to supplement vitamin K2. Vitamin K2 is a very safe nutrient. Based on research data, the United States Pharmacopeia Convention concluded that "at the usual intake level, taking vitamin K2 (MK-7) dietary supplements will not produce a risk of serious events associated with personal or public health."

References

[1]International Osteoporosis Foundation. Facts and statistics.

[2]Cockayne S, Adamson J, Lanham-New S, et al. Vitamin K and the prevention of fractures: Systematic review and meta-analysis of randomized controlled trials[J]. Archives of Internal Medicine, 2006, 166(12): 1256-1261.

[3]Knapen MH, Drummen NE, Smit E, Vermeer C, Theuwissen E. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporos Int 2013; 24: 2499-507.

[4]Booth SL, Dallal G, Shea MK, Gundberg C, Peterson JW, Dawson-Hughes B. Effect of vitamin K supplementation on bone loss in elderly men and women. J Clin Endocrinol Metab 2008; 93: 1217-23.

[5]Binkley N, Harke J, Krueger D, Engelke J, Vallarta-Ast N, Gemar D, et al. Vitamin K treatment reduces undercarboxylated osteocalcin but does not alter bone turnover, density, or geometry in healthy postmenopausal North American women. J Bone Miner Res 2009; 24: 983-91.

[6]Suttie JW. Vitamin K. In: Coates PM, Betz JM, Blackman MR, et al., eds. Encyclopedia of Dietary Supplements. 2nd ed. London and New York: Informa Healthcare; 2010: 851-60.

[7]European Food Safety Authority. Scientific opinion on the substantiation of health claims related to vitamin K and maintenance of bone pursuant to Article 13(1) of Regulation (EC) No 1924/2006. The EFSA Journal 2009; 7: 1228.

[8] Li Shuzhuang. Calcium into the bones: the revolutionary contribution of vitamin K2 to health[M]. China Population Press, 2017.

[9] Chinese Nutrition Society. Dietary Reference Intakes of Nutrients for Chinese Residents (2013 Edition)[M]. China Standards Press, 2014.

[10]Marles RJ, Roe AL, Oketch-Rabah HA. US Pharmacopeial Convention safety evaluation of menaquinone-7, a form of vitamin K. Nutrition Reviews, 2017, 75(7): 553-578.