Vitamin D3 and K2 – Key Nutrients for Body Health. Why Combine Them?

Vitamins D and K are essential for many important functions in the human body, especially bone and immune system health. Both of these vitamins work synergistically and their combination is important for ensuring optimal health. In this article, we will focus on the functions of these vitamins, their sources, the need for different groups of the population and the importance of their combination.

Functions of vitamin D in the body and its sources

Vitamin D contributes to:

• normal function of the immune system
• maintaining normal bones and teeth
• maintaining normal muscle function
• normal absorption/utilization of calcium and phosphorus
• normal blood calcium levels

Vitamin D deficiency can lead to weakened bones (for example, rickets in children or osteomalacia - impaired bone mineralization - in adults) and reduced resistance to infections.

Sources of vitamin D:

• Sunlight: The skin produces vitamin D when exposed to UVB radiation.
• Foods: Fatty fish (salmon, mackerel), egg yolks, fortified dairy products, and plant-based alternatives.
• Dietary supplements: Most often in the form of vitamin D2 (ergocalciferol) or D3 (cholecalciferol), with the D3 form being said to be more biologically effective.

Functions of vitamin K in the body and its sources

Vitamin K contributes to:

• normal blood clotting
• maintaining normal bone condition

Vitamin K is key to activating osteocalcin, a protein essential for depositing calcium into bones, while also preventing its deposition in blood vessels, thereby supporting cardiovascular health.

Sources of vitamin K:

• Vitamin K1 (phylloquinone): Found in green leafy vegetables (spinach, kale, broccoli).
• Vitamin K2 (menaquinone): It is formed by bacterial fermentation, the source is fermented foods (e.g. natto) and some animal products (liver, cheese).

However, the intake of Vitamin K in a typical Central European diet may not be sufficient. Some vitamin K2 is also produced by bacteria naturally present in the human intestine. However, their activity may be weakened in the case of frequent use of antibiotics.

Vitamin K2-MK7: a highly bioavailable form of vitamin K

Vitamin K2 exists in multiple forms (MK-4, MK-7, etc.).  K2-MK7 is a specific form of vitamin K2, known as menaquinone-7 . This vitamin is part of the vitamin K family, which play a key role in regulating calcium metabolism, particularly by promoting calcium deposition in bones and teeth and preventing its accumulation in blood vessels and soft tissues. The MK-7 form is distinguished from other forms of vitamin K by its higher bioavailability , which means it is better absorbed and remains active in the body for a longer period of time.

Features and benefits of K2-MK7: 

• Longer half-life in the body: MK-7 remains in the blood for up to several days, ensuring a consistent effect.
• Higher efficacy: Compared to the MK-4 or K1 form, MK-7 has a more pronounced effect on the activation of osteocalcin and matrix Gla protein, which are key proteins for bone and vascular health.
• Natural origin: MK-7 is mainly obtained from fermented foods, such as traditional Japanese natto (fermented soybeans).

Why combine vitamins D and K? 

Vitamins D and K work synergistically in regulating calcium metabolism. Vitamin D increases the absorption of calcium from the diet, while vitamin K ensures that calcium is properly utilized – deposited in the bones and not in the blood vessel walls.

Research confirms* that the simultaneous use of vitamins D and K has a mutually reinforcing effect, meaning that these vitamins in combination support not only bone health, but also cardiovascular health. This is especially important for postmenopausal women, who are more susceptible to osteoporosis and often have lower levels of vitamins D and K2, but also for seniors who are at risk of bone thinning and vascular calcifications, adolescents during rapid growth, athletes to support regeneration, and people with insufficient exposure to sunlight or limited intake of these vitamins from the diet.

What are liposomal forms of vitamins D and K?

Liposomal forms of vitamins D and K represent a modern technology that increases their absorbability and bioavailability. In this form, lipophilic (oil-soluble) vitamins are enclosed in tiny lipid microspheres, called liposomes, which protect the active substances from degradation by gastric juices and enable their efficient transport into cells. Thanks to this innovative form, the body is able to achieve optimal levels at a lower dosage.

Who should be careful when taking vitamin K?

Vitamin K is generally safe, but caution is needed for people taking anticoagulants (blood thinners) such as warfarin, as it may affect their effectiveness. Patients with blood clotting disorders or those with severe liver disease should also consult a doctor before taking vitamin K2. Although vitamin K2 is well tolerated, allergic reactions may rarely occur. Pregnant and breastfeeding women should follow the recommended doses and consult their doctor if necessary.

Recommended dietary supplements combining vitamins D and K:

• Vitamin D3 + K2 , which provides an optimal combination for bone health and immunity and is formulated with sea buckthorn oil
• NeoLipo D3 + K2 , combining the benefits of liposomal technology with a combination of D3 and K2 for maximum effect.

*Reference:

1. Goddek S. Vitamin D3 and K2 and their potential contribution to reducing the COVID-19 mortality rate. Int J Infect Dis. 2020 Oct;99:286-290.

2. Kidd PM. Vitamins D and K as pleiotropic nutrients: clinical importance to the skeletal and cardiovascular systems and preliminary evidence for synergy. Altern Med Rev. 2010 Sep;15(3):199-222.

3. Iwamoto J, Takeda T, Ichimura S. Effect of combined administration of vitamin D3 and vitamin K2 on bone mineral density of the lumbar spine in postmenopausal women with osteoporosis. J Orthop Sci. 2000;5(6):546-51.

4. Aguayo-Ruiz JI, García-Cobián TA, Pascoe-González S, Sánchez-Enríquez S, Llamas-Covarrubias IM, García-Iglesias T, López-Quintero A, Llamas-Covarrubias MA, Trujillo-Quiroz J, Rivera-Leon EA. Effect of supplementation with vitamins D3 and K2 on undercarboxylated osteocalcin and insulin serum levels in patients with type 2 diabetes mellitus: a randomized, double-blind, clinical trial. Diabetol Metab Syndr. 2020 Aug 18;12:73.

5. Iwamoto J, Takeda T, Ichimura S. Treatment with vitamin D3 and/or vitamin K2 for postmenopausal osteoporosis. Keio J Med. 2003 Sep;52(3):147-50.