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Vitamin D and Immunity – Why is this important?


Vitamin D and Immunity -Why is this important?

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You must not rely on the information on as an alternative to medical advice from your doctor or another professional provider.

If you have any specific questions about any medical matter, you should consult your doctor or another professional provider.

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Vitamin D and immunity go hand in hand.

Vitamin D is a hormone called vitamin accidentally.  Hormones are essential for the body to function smoothly.

Vitamin D is the sunshine hormone. We don’t get enough sunshine the further away from the Equator. Sunshine is vital to build up the brain’s chemistry and to get strong bones.

In these times of Covid 19 infection, many doctors claim that Vitamin D is essential to a strong immunity against all kinds of pathogens. Most people with an autoimmune disease have a deficiency in Vitamin D.

That is well-known among doctors. But they still have problems giving the right amount of vitamin D to their clients, so they are not getting enough to build up immunity!

What is Vitamin D?

Vitamin D is a group of fat-soluble secosteroids responsible for the intestinal absorption of calcium, magnesium, and phosphate.  They are known as vitamin D2 ( ergocalciferol)and D3( cholecalciferol), whereby the last one is the primary natural source, synthesized in the lower epidermis depending on sun exposure.

You can consume the vitamins with your diet, whereas vitamin D2 sources are green leafy vegetables; cholecalciferol is available in a few foods like fatty fish or products from grass-fed cows. You might still know the fish oil we had to drink as children for developing strong bones. Puh, I was not too fond of the taste as a child. But, especially in wintertime, it is an excellent source of Vitamin D3 and Vitamin A, a vitamin essential for eyes and skin.

piece of salmon

Fish oil is still an excellent source of vitamin D3. Many countries enrich dairy products with vitamin D3 to prevent a deficiency. People nowadays are staying more inside their houses and using sun if exposed to the sun to prevent skin cancers.

People who live most days of the year in an area where they are less exposed to the sun, like the most northern and southern part of the planet, have a deficiency making it essential to consume a high vitamin D 3 supplement.

Otherwise, our biological functions are interrupted, creating inflammation and chronic diseases. Doctors admit that Vitamin D3 deficiency is the link to developing autoimmunity and cancers.

Getting vitamin D from the diet or skin synthesis is a biologically inactive process, activated by two protein enzymes called hydroxylases. They introduce a hydroxyl group  (-OH) into an organic compound called Hydroxylation. The activation is done in the liver and the kidneys.

Vitamin D is considered a hormone because it can be synthesized in adequate amounts if under the sun’s influence.  Vitamin D is converted in the liver to calcifediol. The chemical name is 25-hydroxycholecalciferol, which is used for the blood lab to determine Vitamin D 3 in the blood to exclude deficiency.

The kidney synthesizes calcifediol( Hydoxylation) into calcitriol, the active form of  Vitamin D. This hormone in the blood regulates the concentration of calcium and phosphate for healthy growth and remodeling of bone.

Other functions are cell growth, neuromuscular and immune functions. It also reduces inflammation. You see how essential this Vitamin is, especially in these times of Covid 19. If you have read my article about the immune system and its functions, you will understand the importance of this vitamin to immunity.

Vitamin D is essential for calcium synthesis. In the 19 century, they discovered that poor people who lived near the coalfields had developed a Rickets disease or the “English Disease.” Children grew soft bones; even newborn babies were already born with this disease. The sky was black from the coal preventing the sun from penetrating these layers.

They initially thought it was because of England’s dull and wet climate, which does, of course, contribute to the development of this disease. And most likely, the low diet, the dirty skin, early weaning, and impure air haven’t done any good.

In agricultural areas, they had nearly none who suffered from this disease. We know now the reason. The air was clean, and the people living there were eating a proper diet receiving enough vitamin D to prevent the Rickets from developing.

The problem was recognized in cold and wet climates like the Netherlands, England, Germany, and Northern Italy. Still, it was absent in tropical and sub-tropical climates, undoubtedly a marvelous discovery.

sunbathing woman

They discovered that a sunlight deficiency did the damage, accompanied by insufficient calcium intake from an improper diet. Doctors didn’t know the connection between Vitamin D and Calcium intake at these times.

They studied rats’ effects of UV light and enriched their diets with cod liver oil. At the end of the 18th century, they used cod liver oil to treat rheumatism and used it for Rickets. But they didn’t understand why cod liver oil helped with this disease.

At the beginning of the 20th century, they discovered Vitamin D as a pre- hormone. They observed the results but couldn’t explain the chemical process until then.

Researchers have learned that an adequate calcium intake accompanied by sun exposure and cod liver oil can prevent Rickets’ development.

Asian migrants who came to England suffered very quickly from the same conditions. But when they used the Vitamin D supplements, cod liver oil and consumed a sufficient amount of calcium, the disease disappeared.

Because Vitamin D has a strong effect on the immune system and cell growth, it is the right choice against pathogens that try to weaken the immune system. That is an interesting fact, especially by influenza and Covid 19’s infections.

Does Vitamin D Boost Immunity?

Yes, it does!  Vitamin D, the sunshine hormone, dramatically influences our immunity.

In the 19th and 20th century patients with tuberculosis were sent to sanatoriums to cure their illness; left untreated at that time was commonly a deadly disease. Wet, cold climate, little heating in the houses, improper diet, avoiding the sun made it easy for this disease to develop.a house in the mountains, cold and wet

In these sanatoriums, people were opposed to sunlight, got a proper diet and cod liver oil to heal the disease.  Lower serum levels of Vitamin D3 showed an increase in infections and inflammation. There has been the highest infection rate reported in the winter than in the summer.

Doctors concluded that the sunlight and the increase of Vitamin D 3 impacted immunity. People with lower serum levels often suffering from respiratory tract infections improved very much when given high vitamin D 3.

There are relevant fewer influenza infections reported in summer, which shows the sun light’s importance again.

Using a sunbed in winter with the proper care is a perfect treatment against infections and depression. But of course, don’t overdo the tanning. There are saunas where you can get sunlight therapy reporting the same beneficial effects on the body and brain.

Vitamin D And Vitamin K- Why Using Them Together?

The critical point is that you never should consume high amounts of Vitamin D3 without taking Vitamin K. They are both fat-soluble vitamins and essential for calcium metabolism.  The synergistic interplay of these vitamins is still not accepted.

As a nurse, I see that more older people are treated with a low Vitamin D3 without adequate Vitamin K intake. Older people’s skin is less likely to get penetrated by the sun.

I know many older folks stay the most inside the house, which doesn’t help their health condition. They are prone to all kinds of infection and inflammation.

The amount of vitamin D 3 described by their GP’s is too little. In my eyes, it is like a placebo given to them. But some doctors prescribe 20000 i.U. once a week, which is about 2800 a day. That is better.

The synergistic interplay between the vitamins affects the most bones and cardiovascular health. It is well studied that these two vitamins complement each other.

Vitamin D is responsible for producing Vitamin K-dependent proteins requiring enough vitamin K for the carboxylation to function correctly.

They have very well studied the connection in the menopausal women who suffer due to the declined sex hormones very often from osteoporosis reducing bone mass. Menopausal women are easy to have fractures, sometimes spontaneous.

Doctors still prescribe a high amount of calcium, which circulates in the blood without being controlled by vitamin D. The veins, arteries, and organs start to calcify, hardening the tissue.

These women have a high chance of suffering a heart attack or stroke because their veins and arteries become hard from the deposited calcium. They need vitamin D to bring calcium to the bones.

This is the point where vitamin K comes in. Vitamin  K is necessary for the body to get the calcium out of the tissues, veins, and arteries and implement it into the bones. For this reason, you should never consume vitamin D without K.

What is Vitamin K?

Vitamin K is also a group of fat-soluble vitamins playing a role in blood clotting, bone metabolism, and regulating blood calcium levels, which I have already explained.

Vitamin K1, also called phylloquinone, is needed by the body to produce prothrombin, a protein relevant for blood clotting. People who use warfarin or coumadin, blood-thinning medications, should always ask their doctor before taking any vitamin K, which influences blood clotting.

Vitamin K1 comes from plants, so deficiency is rare. The source of Menaquinone or vitamin K2 is animal products and fermented food. A very high amount of K2 available is in Natto, a Japanese derivative of fermentation. 

fermented cabbage in a jar

Vitamin K2 is a significant factor preventing calcification, the most risk factor for heart disease and stroke. Vitamin K helps keep the blood pressure balanced by avoiding the veins and arteries from hardening due to calcification.

If we get older, calcification is the natural process of dying, and it naturally occurs with age. But you can prevent your blood vessels and tissues from premature calcification by eating the proper diet and moving your body.

Final Thought

Taking Vitamin D3 and K2 together is essential for healing the body. Many vitamins function as a pair, interacting in the body. To prevent calcification in your blood vessels, you need to consume always D3 and K2 together.

If you use calcium, you need to use magnesium and both vitamins, and you will have great results for your bone health, blood system, and immune system.

For every 10000 units of vitamin D 3, you need 100 mcg vitamin K2 to be on the safe side.

Always get first your blood tests done to prevent an overdose of vitamin D3 and because you want to create the right balance.

The suitable vitamin K2 is menaquinone – 7(MK-7).  They often offer MK-4 supplements, but that is synthetical and not recognized by the body.

A fair amount to start with is 5000 units of vitamin D3, accompanied by 75 – 100 mcg Vitamin K2. Don’t exceed the amount without being tested. Ask your doctor or the pharmacist.

I would love to hear what you think? What are your experiences?

To your health,




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10 thoughts on “Vitamin D and Immunity – Why is this important?

  1. As you said, Taking Vitamin D3 and K2 together is an art of healing. Many vitamins function as a pair, interacting in the body. To prevent calcification in your blood vessels, you need to consume always D3 and K2 together, I think it should be shared with us by our doctors. Thank you for sharing this valuable information.

    1. Thank you very much, Shahlla! I love your comment! You confirm every word I have written, and you are so right; we need to get this message out. People need to take responsibility and get informed. Are you a doctor or nurse?

  2. Abigail says:

    Getting enough Vitamin D is essential for us humans and this is 10 times more important now with this pandemic. Our immune system needs the sunlight to receive that Vitamin D and other benefits, so it can battle any infection. It is highly recommended that we go outside, in the morning, for at least 20-30 minutes and just take in the sun. Even on days when the sun is not as powerful, this time will be beneficial. This will help us strengthen our immune system, help us sleep better at night, give us more energy during the day and generally make us feel happier. It’s such a simple thing to do and it is so important and yet many people don’t know how much better their lives would be by just getting more sunlight, especially in the morning.

    1. Thank you, Abigail, for your thoughtful comment! Yes, you are very right! We need to have Vitamin D for our immunity. The sun is so important, also being outside, even the sun is not shining. People need to know that they are getting ill if they spend too much time at home. Very well said.

  3. Sylvia, I have a question:

    Is it better to take Vitamin D once or twice a week in larger amounts or to take it daily?

    For example, if I were to take 20000 i.U. on Monday and then another 20000 i.U. again on Friday, would that be better than taking 5000 i.U. daily?

    Just trying to find out which option is better.

    Also how much Vitamin K would I have to take for each of these cases?

    1. Hi Noah,
      I think it is always better to take it daily. I know some doctors recommend taking a huge amount of Vitamin D3 once a week. It is better to use it daily with the right amount of Vitamin K. For 5000 i.U. you need to take 100 mcg Vitamin K. You remember, for 10000 i.U. Vit D3 you take 200 mcg Vit K2. So you take now the half. But if you take much Vitamin D3, you need to get your lab done before starting and after 3 months of consuming the vitamins. In this manner, you keep your levels checked. Very important, so you will not get toxicity.

  4. Roberta says:

    I didn’t know Vitamin D is so important for us. I also did not know that you need Vitamin K alongside Vitamin D. I’ve been taking Vitamin D wrong for so much time! I’m disappointed that so many doctors still prescribe Vitamin D wrongly when they (or some of them at least) know that it won’t stick 🙁

    Thank you for sharing your thoughts, Sylvia and I’ll be sure to start taking these two vitamins together and see how I feel after a few weeks.

    1. Hi Roberta, Thank you very much for your comment! It is really a shame that still so many doctors are doing it wrong. Do not worry; get your blood test done, and then start taking Vitamin K with D3. Then you should be fine! Do you know that you can order a blood test for Vitamin D3 online?

  5. Hello Sylvia. Thank you for sharing about D vitamin. I didn’t know that it actually is a hormone that is accidentally called a vitamin. Good to know!. I think your article is very well written and very informative. I will look back on your site whenever I need to be updated about health stuff.

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