Vitamin D3 and K2: The Immune-Boosting Combo


In a previous post (Don’t Ditch Your Daily Dose of Vitamin D), we have enumerated a long list of benefits from the sunshine vitamin. The blog also mentioned the crucial partnership between vitamin D3 and K2. One of the underlying and recurring ideas is vitamin D’s ability to help the immune system. But did you know that vitamin K2 also has its own immune-boosting merits? Now since winter is just around the corner, we feel like it would be a disservice not to emphasize how the vitamins can help our body prevent or ward off diseases.

Vitamins D3 and K2: A Review

Vitamin D

Vitamin D has two forms. One of them is ergocalciferol also known as D2, obtained by ingesting foods or plant materials that have been exposed to sunlight and UV radiation. Vitamin D3 (cholecalciferol) on the other hand, is formed in the skin upon contact with sunlight. Upon careful study of the two forms, it has been concluded that vitamin D2’s potency is less than one-third that of vitamin D3 in humans. Vitamin D3 also increases serum 25-hydroxyvitamin D, the active form of vitamin D, more efficiently than vitamin D2. In terms of duration of action, cholecalciferol is still the winner of the two vitamin D forms.

Vitamin K

Like Vitamin D, there are also types of vitamin K – the two main ones are K1 and K2. K1 is also called phylloquinone. As the name suggests, it is found mostly in plant foods and is best known for its clotting factor. On the other hand, K2 (menaquinone) is found in animal products, fermented foods, and is produced by gut bacteria. It is the most usable and absorbable form and is known best for moving calcium around. This translates to putting calcium into the bones, removing it from the arteries, and for immune signaling. Although vitamin K2 is one of the lesser-known vitamins, it is extremely important for the optimal function of D3. In fact, to some extent, vitamin D3 would be dangerous if not taken together with K2.

Although there are still very few research studies on the Vitamin D3 and K2 combo, D3 is one of the more popular vitamins considered as a potent solution to a number of conditions. K2, on the other hand, is the new kid on the block. Having said that, sufficient evidence still suggests that these two vitamins work best together and whatever good things D3 can do to our body still stands and, in fact, may even be reinforced with the addition of K2.

So how do vitamins D3 and K2 boost the immune system?

1. It activates our immune defenses.

T-cells are a type of white blood cell that is essential for human immunity. Though there are several kinds of T-cells, they can be broadly categorized as killer T-cells and helper T-cells. Killer T-cells seek out and destroy cells that are damaged or infected. Helper cells “help” the body orchestrate an immune response. In all of these functions, vitamin D is of utmost importance.

Numerous research studies prove that vitamin D triggers T-cells through the vitamin D receptor. If we are deficient in this vitamin, then T-cells remain dormant and unable to seek out and destroy foreign pathogens.

2. It strengthens our innate immunity.

The innate immune system response serves as the front-liner against pathogens like viruses, bacteria, and fungi. Once it identifies a foreign invader, its first task is to trigger a series of events to destroy the possible cause of disease or infection. Vitamin D3 and K2 help in feeding this mechanism.

Studies on the antimicrobial potency of vitamin D showed that it up-regulates our body’s production of anti-microbial peptides, particularly cathelicidin. Aside from cathelicidin’s ability to directly stop microbial activity, it can also prompt specific defense responses within the body.

3. It helps shorten the number of sick days.

Speaking of the body’s specific defense, vitamin D3 and K2 also improve adaptive immunity. This significantly shortens the course of the infection and helps the body recover faster. This immune-boosting benefit is proven and illustrated in a study of 800 military recruits in Finland. The subjects who had lower vitamin D lost more days of active duty from respiratory and other infections. Separate studies have also shown the effect of D3 on the rates of influenza, bacterial vaginosis, and HIV. The common denominator among those studies is the relationship between low vitamin D levels and increased frequency of infection.

4. It stops the progression of existing autoimmune disease and suppresses autoimmunity.

D3 is great news for people who have issues with autoimmunity. Several studies in animal models show that specific autoimmune diseases can actually be prevented or managed by the administration of vitamin D3 to patients. Conditions include inflammatory bowel diseases, collagen-induced arthritis, type 1 diabetes, autoimmune encephalomyelitis, and lupus.

Some studies have also linked low vitamin D levels to the development of multiple sclerosis, rheumatoid arthritis, diabetes, and lupus. Even low vitamin D exposure of babies within the uterus is associated with the increased risk of pancreatic autoimmunity. Vitamin D also has the ability to suppress autoimmunity.

5. It reduces inflammation and helps reduce tissue damage.

If you are still not worried about inflammation, maybe you should read our post about chronic inflammation and know that this is a serious matter that needs to be addressed. Long-term inflammation can cause and aggravate a number of health conditions. Luckily, D3 can help you with this.

A study of 2,070 adult individuals over the age of 65, concluded that poor vitamin D level is linked to moderate and severe pain from inflammation. Separate research reinforced this idea by proving that vitamin D lowers inflammation. Upon administration, vitamin D lands on the vitamin D receptor to start core gene signaling that reduces inflammation. It regulates the production of inflammatory cytokines and stops the proliferation of pro-inflammatory cells.

Are You Vitamin D3 and K2 Deficient?

The recommended daily vitamin D intake is 4,000 IU. In most people, ample sun exposure coupled with a vitamin-rich diet is enough to satisfy the daily requirement. However, certain individuals are at higher risk of vitamin deficiency:

  • Pregnant or breastfeeding women
  • Elderly
  • Weight lifters or competitive athletes
  • Dark-skinned individuals
  • Those with autoimmune diseases
  • People located in areas without enough sunlight

As for K2, diet alone is not usually enough to achieve our bodies’ daily requirements of 180 mcg per day, especially given that some are saying that 280mcg might not actually be enough. And although it is also produced by gut bacteria in the large intestine, antibiotic intake and poor food choices can contribute to a vitamin K2 deficiency.

Symptoms of vitamin D3 and K2 deficiency may include frequent sickness, fatigue, depression, impaired wound healing, bleeding or bruising easily, muscle pain, bone loss, and hair loss.

This is why supplementation is highly beneficial for bone health, cardiovascular function, better immunity, and overall bodily function. One quality brand to consider is the  D3 K2 Mulsion from Genestra. The emulsified form of D3 and K2 can be easily absorbed by the body and would greatly aid in meeting your vitamin needs. Just 10 drops of the D3K2 Mulsion formula plus a diet of D3-rich sources (such as wild-caught fish, sunflower seeds, shitake mushrooms, and almond milk) and you are good to go. Or if you have been prescribed by your doctor to take high doses of D3, go on and match it with your own K2 bottle too so you can make the most out of your vitamins. MK-7 (Vitamin K2) 150 mcg 100 Vcaps is a great option if you’re looking at the best form of K2.

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Prietl, B., Treiber, G., Pieber, T. R., & Amrein, K. (2013). Vitamin D and immune function. Nutrients, 5(7), 2502-2521. (2009) Beginners Guide to T Cells.

Mangin, M., Sinha, R., & Fincher, K. (2014). Inflammation and vitamin D: the infection connection. Inflammation Research, 63(10), 803-819.

University of Copenhagen. (2010, March 8). Vitamin D crucial to activating immune defenses. ScienceDaily.