How to replenish vitamin K deficiency?

Vitamin K is a group of compounds that the body uses to activate certain proteins in the blood and tissues. The most commonly discussed are K1 (phylloquinone) from plant products and K2 (menaquinones, for example MK-7) present in some fermented and matured products. A deficiency does not always cause obvious symptoms right away, so it is easy to overlook, especially when fat absorption is impaired or the diet is very monotonous and lacking in variety for a long period of time.

1. Main functions of vitamin K
2. Vitamin K in the diet
3. Vitamin K supplementation
4. Vitamin K supplementation

Main functions of vitamin K

Vitamin K is most commonly associated with blood clotting. It helps activate several proteins that build a clot (a plug of platelets and fibrin that stops bleeding). This happens through a specific modification that allows clotting factors and proteins that regulate clotting to bind calcium ions and function properly. When there is not enough vitamin K, some of these proteins remain in a less active form, which can lead to easier bruising, prolonged bleeding from minor wounds or nosebleeds. This is a life-threatening condition when a major injury occurs.

At the same time, vitamin K participates in calcium metabolism in tissues, especially in bones and blood vessels. In bones, it influences the ‘maturation’ of osteocalcin (a protein that helps bind calcium in bone tissue), and in blood vessel walls, it influences the activity of MGP (matrix Gla protein, a protein that inhibits calcium deposition in artery walls). This translates into bone density and resistance to osteoporosis, as well as protection of the cardiovascular system.

Vitamin K in the diet

It is best to start supplementing vitamin K with your diet, as regular, repeated portions ensure the most stable increases in concentration in the body. The K1 form (phylloquinone) is most easily obtained from green leafy vegetables such as kale, spinach, parsley and broccoli. The K2 version (menaquinones) is more common in fermented and matured products, such as soy and milk products. Its content in these products depends on the technology used and the maturation time. Because vitamin K is fat-soluble, adding fat to a meal (e.g. olive oil, linseed oil, avocado) improves absorption, and a low-fat diet can make it difficult to utilise even a decent amount from food.

Vitamin K requirements in different age groups

Vitamin K supplementation

Vitamin K supplementation is most often based on two main forms, K1 and K2, with K2, especially its MK-7 and MK-4 forms, being used more frequently in meta-analyses assessing its effects on bones and blood vessels, as they remain in the blood longer and are therefore available to tissues for most of the day. In analyses involving adults, the doses used varied greatly, but in most studies they ranged from about 90 to 200 micrograms per day for MK-7 and from several dozen to several hundred micrograms for K1.

In many studies, vitamin K supplements were combined with vitamin D and calcium, as these components work in the same area, i.e. calcium metabolism. Vitamin D increases calcium absorption from the intestines, while vitamin K helps to ‘direct’ it to the bones and reduce its deposition in the blood vessels.

"A unique solution is supplements that contain a mixture of Omega 3 fatty acids, Vitamin D3 and Vitamin K2. This is an excellent solution for people who are looking for such a universal combination." Tomasz Maciołek - Physiotherapist

Vitamin K supplementation

In large analyses of numerous studies involving humans, two main benefits of vitamin K supplementation were most often noted, namely bone support and effects on blood vessels. In postmenopausal women and people with weakened bone structure, regular intake of vitamin K2 was associated with a small but consistent increase in bone density. Some meta-analyses also observed a lower incidence of certain fractures, especially in the spine.

The second important area concerned blood vessels. It was noted that vitamin K supplementation was associated with slower calcium deposition in the artery walls, which in practice means less ‘hardening’ of the vessels and potentially greater elasticity. In these studies, other indirect indicators related to blood vessel protection also improved, clearly demonstrating the important role vitamin K plays throughout the body.

Sources:

• Mladěnka, P., Macáková, K., Kujovská Krčmová, L., Javorská, L., Mrštná, K., Carazo, A., Protti, M., Remião, F., Nováková, L., & OEMONOM researchers and collaborators (2022). Vitamin K - sources, physiological role, kinetics, deficiency, detection, therapeutic use, and toxicity. Nutrition reviews, 80(4), 677–698. https://doi.org/10.1093/nutrit/nuab061
• Ma, M. L., Ma, Z. J., He, Y. L., Sun, H., Yang, B., Ruan, B. J., Zhan, W. D., Li, S. X., Dong, H., & Wang, Y. X. (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
• Cockayne, S., Adamson, J., Lanham-New, S., Shearer, M. J., Gilbody, S., & Torgerson, D. J. (2006). Vitamin K and the prevention of fractures: systematic review and meta-analysis of randomized controlled trials. Archives of internal medicine, 166(12), 1256–1261. https://doi.org/10.1001/archinte.166.12.1256
• Li, T., Wang, Y., & Tu, W. P. (2023). Vitamin K supplementation and vascular calcification: a systematic review and meta-analysis of randomized controlled trials. Frontiers in nutrition, 10, 1115069. https://doi.org/10.3389/fnut.2023.1115069