I remember the days when doctors not trained in nutrition recommended people with osteoporosis take 1500 mg to 2000 mg daily. Patients would complain of constipation and digestive upset. However, besides the fact one cannot absorb all that amount of calcium at one time, something more sinister may have been taking place, and that is the deposition of excess calcium in the arteries.
Integrative doctors like me know that there are many minerals and vitamins that work in conjunction with calcium for the proper formation of bone. Some of the examples include vitamin D, phosphorous, silica, magnesium, and K2. The nutrient I want to focus on right now is vitamin K2.
Vitamin K2, also known as menaquinone, is different than vitamin K1, also chemically referred to as phylloquinone. K1 is found in foods such as green leafy vegetables, such as kale, spinach, cabbage, as well as plant foods such as broccoli. However, K2 is much more difficult to attain in the American diet, and is the reason I often see it deficient on blood K2 testing. K2 is mainly found in fermented foods, such as the fermented soy product commonly consumed in Japan known as Natto. Also, K2 can be synthesized by intestinal bacteria . There are 12 subtypes of K2, with MK-4 and MK-7 demonstrating bone promotion and increased bone strength effects
K2 has a direct link to calcium balance. K2 is involved in facilitating the binding of calcium to bone proteins (Gla proteins). In addition, K2 has been shown to stimulate cells which form bone and suppress cells that breakdown bone by suppressing the activation of NF-κB , which is an inflammatory mediator. The K2 effects on osteoblasts and osteoclasts contribute to bone formation and a reduction in bone resorption. Additional research has shown that K2 also decreases fracture risk, reduces urinary calcium loss, and lowers serum alkaline phosphatase levels.
A meta-analysis and systematic review involving nine randomized controlled trials investigated the efficacy and safety of vitamin K2 for postmenopausal women with osteoporosis. The supplementation of K2 significantly increased the bone mineral densities of the lumbar and forearm regions. Moreover, there were no serious adverse events related to supplementation of K2.
A meta-analysis of 19 randomized controlled trials also found that K2 supplementation improved vertebral bone mineral density and the prevention of fractures in postmenopausal women with osteoporosis.
Mk-7 at a dose of 180 mcg per day was shown to improve vertebral height loss after two to three years compared to placebo in healthy postmenopausal women. High dose K2 (45 mg per day) combined with calcium supplementation has been shown to maintain lumbar bone mineral density and inhibit the occurrence of new bone fractures for Japanese women with osteoporosis.
In summary, vitamin K2 has been shown to improve bone density and reduce fracture risk. Most studies have been performed on menopausal and postmenopausal women with osteoporosis. The research demonstrates that vitamin K2 should be considered a nutritional treatment for the prevention and treatment of osteoporosis. Also, be aware that K2 prevents calcium build up in the arteries. This is important since cardiovascular disease is the number one killer in America. I always recommend that patients taking vitamin D3 supplements to also supplement K2 along with it. Also, bone formulas should contain K2. Both are fat soluble and should be taken with food.
References
Huang, Z.-B., Wan, S.-L., Lu, Y.-J., Ning, L., Liu, C., & Fan, S.-W. (2015). Does vitamin K2 play a role in the prevention and treatment of osteoporosis for postmenopausal women: A meta-analysis of randomized controlled trials. Osteoporosis International, 26(3), 1175–1186. https://doi.org/10.1007/s00198-014-2989-6
Knapen, M. H. J., Drummen, N. E., Smit, E., Vermeer, C., & Theuwissen, E. (2013). Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporosis International, 24(9), 2499–2507. https://doi.org/10.1007/s00198-013-2325-6
Ma, M., Ma, Z., He, Y., Sun, H., Yang, B., Ruan, B., Zhan, W., Li, S., Dong, H., & Wang, Y. (2022). Efficacy of vitamin K2 in the prevention and treatment of postmenopausal osteoporosis: A systematic review and meta-analysis of randomized controlled trials. Frontiers in Public Health, 10, 979649. https://doi.org/10.3389/fpubh.2022.979649
Shiraki, M., Shiraki, Y., Aoki, C., & Miura, M. (2000). Vitamin K2 (Menatetrenone) Effectively Prevents Fractures and Sustains Lumbar Bone Mineral Density in Osteoporosis. Journal of Bone and Mineral Research, 15(3), 515–521. https://doi.org/10.1359/jbmr.2000.15.3.515
Yan, Q., Zhang, T., O’Connor, C., Barlow, J. W., Walsh, J., Scalabrino, G., Xu, F., & Sheridan, H. (2023). The biological responses of vitamin K2: A comprehensive review. Food Science & Nutrition, 11(4), 1634–1656. https://doi.org/10.1002/fsn3.3213
Zhang, M., Zhang, Q., Du, P., Chen, X., & Zhang, Y. (2023). Roles of vitamin K‑dependent protein in biomineralization (Review). International Journal of Molecular Medicine, 53(1), 6. https://doi.org/10.3892/ijmm.2023.5330
Zhou, M., Han, S., Zhang, W., & Wu, D. (2022). Efficacy and safety of vitamin K2 for postmenopausal women with osteoporosis at a long-term follow-up: Meta-analysis and systematic review. Journal of Bone and Mineral Metabolism, 40(5), 763–772. https://doi.org/10.1007/s00774-022-01342-6
