Part 2: The role of vitamins in the proper functioning of the immune system.

"Vitamins A, C, E and D are particularly important for the immune system. The vitamins, in addition to their basic roles, have also an impact on the immune system." – D. Chlebna-Sokol, J. Karalus, A. Łupińska "The importance of vitamins in the prevention of autumnal-winter infections", 2012.

Vitamin A (retinol) significantly influences the immune system. It also is responsible for the endyma of the digestive and respiratory systems, protecting the body against infections. It means that its deficiency will cause disorders of the immune system and thus susceptibility to infection. Lack of vitamin A is especially dangerous for children and teenagers, for it can lead to atrophy of the thymus, spleen and lymph nodes (vital elements of the immune system). Vitamin A is essential in the creation of lymphocytes (our defenders - T cells). It also promotes the regenerative capacity of cells. It protects the epithelium of the skin and mucous membranes, preventing the invasion of microorganisms.

Immune system cells are particularly sensitive to oxidation. Vitamin A (especially β-carotene, which is transformed in the digestive system into vitamin A) has antioxidant properties and therefore plays a protective role against free radicals and their oxygen derivatives.

In addition, vitamin A stimulates the proper growth and development of skeletal system and also participates in the process of eyesight and maintains proper condition of hair and nails.

Deficiencies of this vitamin can result in:

- disturbances in the seeing process, e.g. an amblyopia at dusk (called a night blindness),

- degeneration of the epithelium covering the mucous membranes of the respiratory and digestive systems leading to loss of immunity and greater susceptibility to infection,

- inhibiting the growth and development of young organisms,

- malfunction in the nervous system.

The main groups of products supplying vitamin A in the daily diet are: fish oil, offal (especially liver) and dairy products: milk, cheese, egg yolk and butter.

Whereas β-carotene is found in vegetables: carrots, kale, spinach, red peppers, sweet potatoes, pumpkins and in fruits: apricots, peaches, plums and cherries.

However, it should be noted that pesticides and nitrophosphates today used in agriculture widely disturb the conversion of β-carotene to vitamin A.


Vitamin E (tocopherol) is necessary in the process of cell growth and maintaining the permeability of cell membranes. The most crucial function of the vitamin in protecting the body is its antioxidant effect. It is a natural, very powerful antioxidant that is present in the membranes of all cells. Additionally, it protects vitamin A and saturated fatty acids against oxidation in the body's cells.

Research conducted in 1997 showed that people diagnosed with rheumatoid arthritis and lupus had lower levels of vitamins A and E - Ann Rheum Dis. May 1997, 323-5.

Moreover, vitamin E supports the blood-vascular system. It is desirable in anti-heart attack prophylaxis and also reduces the risk of coronary disease.

Its deficiency may also lead to flaccidity and even the atrophy of the muscles, disorder of the growing process, nerve damage, skin changes (discoloration and spots), exhaustion and general weakness of the body, leading to bigger susceptibility to infections.

Vitamin E is primarily found in plant products, as well as in small amounts in fish, poultry and milk. The richest source of tocopherols are oils: from wheat sprouts, sunflower, rape, soybean, corn, as well as sunflower seeds, shoots and green leafy vegetables (based on: Dymarska E, Grochowalska A, Krauss H. “Impact of nutrition on the immune system. Immunomodulatory action of fatty acids, vitamins and minerals and antioxidants ”, Now Lek 2013, 82 (3): 222-231).

Vitamins A and E can also be supplemented. I can recommend Swanson and Puritan’s Pride vitamins. Taking vitamin A and E is good to combine with selenium supplementation, which facilitates their absorption and also has a good effect on hair and nails as well as the immune system.

Remember, both vitamins are dissolved in fat. It is therefore best to take them after a meal (about an hour) containing animal fat (butter).

The Forever company offers a supplement (Forever A-Beta-CarE) that immediately absorbs β-carotene, vitamin E and selenium in one dose in the right proportion. This is the optimal dose for daily supplementation (7.5 mg β-carotene, 67 mg vitamin E, 25 µg selenium). However, if we suffer from major deficiencies of vitamin A or E, I recommend using supplements with a higher vitamin proportion.


Vitamin C (ascorbic acid) is present in high concentration in leukocytes. It strengthens the body's immunity. Its action is supported by vitamin E. Due to the fact that during infection vitamin C is quickly absorbed, it is recommended to supplement it in the autumn and winter time.

Vitamin C has an antioxidant effect (prevents DNA damage caused by free radicals and also supports damages’ repair by affecting repair enzymes).

In addition, vitamin C is necessary for collagen synthesis and strengthening blood vessels. It facilitates the absorption of iron from the digestive system and participates in the regeneration of vitamin E. Vitamin C relieves symptoms of asthma exacerbation. It makes gums stronger concurrently eliminating bacteria that cause tooth decay. The vitamin also facilitates wound healing.

Deficiency of vitamin C may lead to:

- lower immunity,

- burst of blood vessels,

- swelling and pain in the joints,

- scurvy.

Vitamin C is found primarily in plants. The biggest concentration of this vitamin we can find in: parsley, pepper, brussels sprouts, kohlrabi, broccoli. Among the fruits, the largest record holder in terms of vitamin C content is sea buckthorn, followed by rosehips, blackcurrant, next strawberries, kiwi and citrus fruits. Very high content of this vitamin is characteristic for such plants such as: a nettle, five-flavor berry, oregano and chives.

Vitamin C contained in food is one of the most sensitive vitamins to external factors. It is damaged (oxidation) by high temperature (the exception is sea buckthorn fruit), exposure to light and direct contact with air.

Vitamin C is a vitamin that dissolves in water. Its intake during a meal also has a positive effect on blood sugar level.

In case of supplementing the vitamin, I recommend Swanson and Puritan’s Pride products, which offer vitamin C in a concentration of 1000 mg, as well as a Forever supplement - Forever Absorbent-C. It is a combination of vitamin C with citrus flavonoids and oat bran (fiber) at a dose of 60mg vitamin C and 3.7 mg bioflavonides in one tablet. The fiber contained in a tablet extends the absorption time and makes the vitamin almost 100% absorbed. Flavonides, on the other hand, strengthen the antioxidant effect of vitamin C. This is the optimal dose for daily demand but if you suffer from a greater deficiency of vitamin C, I recommend using supplements with a higher dose of vitamin.


Finally, the queen of all vitamins:

Vitamin D (cholecalciferol) has a very significant effect on the whole body. "The discovery of the VDR receptor (Vitamin D Receptor - 2005) for vitamin D in most human extracellular cells suggested its role in other body systems and organs" - "Vitamin D - myths and facts", habilitated doctor of med. science Jarosław Drobnik, professor of PMWSZ Department of Gerontology, Department of Public Health WNoZ Medical University of Wroclaw. "Analysis of the results of over 50,000 clinical researches led to the conclusion that D3 is not really a vitamin but a hormone that affects almost all cells of the human body." - Halina Kotaś, "Treatment with vitamin D3 in high doses", Nieznany Świat 8/2018 (332). Such conclusions were reached by the American biochemist Jeff T. Bowles who studied the effect of this vitamin on the human body for 20 years. He also experimented on himself, using high-dose vitamin D therapy for his illness, with positive results. Conclusions and observations published in the book "THE MIRACULOUS RESULTS OF EXTREMELY HIGH DOSES OF THE SUNSHINE HORMONE VITAMIN D3 MY EXPERIMENT WITH HUGE DOSES OF D3 FROM 25,000 to 50,000 to 100,000 IU A Day OVER A 1 YEAR PERIOD". Many years of analysis, experience and research led Jeff Bowles to the conclusion that taking vitamin D3 (in combination with K2) in very high doses, allowing the body to achieve its adequate saturation, improves general health. The vitamin D3 and K2 duo ensure proper distribution of calcium in the body.

Vitamin D3 has a very significant impact on our immune system. It participates, among others, in the production of natural antibiotics and the regulation of lymphocyte function. Japanese researchers concluded that the risk of getting influenza decreased by 60% in children aged 6-15 years who received vitamin D3 in a daily dose of 30 µg. – A. J Clin Natur, May 2010 91 (5).

Vitamin D3 deficiency may "double the risk of heart disease" - Circulation 29.01.2008, 117 (4).

"World experts emphasize that vitamin D deficiencies are found in over 80 different autoimmune diseases. According to prof. Yehuda Shoenfeld, patients with autoimmune diseases require regular monitoring metabolites of vitamin D and rational supplementation."-"Vitamin D deficiency and autoimmune diseases ", Puls Medycyny, 02.11.2017.

"Vitamin D supplementation is also necessary in case of patients with thyroid disease, because it has also been found a correlation between vitamin D deficiency and a higher proportion of patients. According to the Israeli researcher, the level of thyroid antibodies (anti-TPO) correlates with the level of vitamin D."- "Vitamin D deficiency and autoimmune diseases ", Puls Medycyny, 02.11.2017.

Vitamin D deficiency is also associated with such diseases as cancer and infectious diseases. Too low level of this vitamin can cause hypertension in people with fair complexion (because most of them suffer from D3 deficiency). It may also be associated with such diseases as: depression, rheumatic diseases, osteoporosis, asthma, multiple sclerosis, Alzheimer's, metabolic disorders (obesity, sugar level fluctuations).

It should not be surprising the statement of prof. Lorentz from the Department of Biochemistry, Radioimmunology and Experimental Medicine of the Children's Health Center in Warsaw that: "In the USA it is estimated that only 9% of residents have normal vitamin D levels. In Europe it is similar, in the future it may be even worse, because for 10 years the percentage of people from the correct concentration of this vitamin." - "Experts: almost every Pole should take vitamin D", PAP (Polish Press Agency) - Science in Poland, Zbigniew Wojtasiński, 12/07/2014.

"Studies have indicated that there is a high prevalence of vitamin D deficiency worldwide. Vitamin D deficiency may affect the immune system as vitamin D plays an immunomodulation role, enhancing innate immunity by up-regulating the expression and secretion of antimicrobial peptides, which boosts mucosal defences.”- that information was published by World Health Organization - WHO "Vitamin D for prevention of respiratory tract infections", June 2017.

It should also be emphasized that some forms of treatment, especially steroids, can lead to a reduction of the vitamin D3 in the body. According to a study by Albert Einstein College of Medicine from Yeshiva University in New York, corticosteroids such as prednisone, often prescribed to reduce inflammation, can reduce calcium absorption and disrupt vitamin D metabolism. These effects can further contribute to bone loss and development osteoporosis. Drugs of this type are prescribed for a wide variety of conditions, including rheumatoid arthritis (RA) and lupus, as well as multiple sclerosis, some types of cancer, asthma and skin rashes – including those caused by poison ivy. Corticosteroids also occur in skin creams, injections and inhalational forms - "Oral Corticosteroids Can Lead to Vitamin D Deficiency", Arthitis Foundation.

Do not be afraid of vitamin D3 overdose.

Mr. Bowles's research showed that the level of vitamin D3 intoxication was extremely rare in the cases he studied and only when it was taken in extremely high doses for months, i.e. 1,000,000 IU daily or simultaneously occurred a significant deficiency of vitamin K2.

I do not consciously give the recommended doses of vitamin. I leave the conclusions presented above to everyone for their own assessment.

Let's start with examining the level of this vitamin. Vitamin D deficiency can be determined by performing a blood test for a concentration of 25 (OH) D. You should pay attention: many doctors mistakenly recommend that patients test the level of 1.25 (OH) 2 D, which, however, does not make the right diagnosis. Why is this the wrong test? Because it often shows normal or even elevated vitamin D level in people who are de facto deficient of it.

Vitamin D is difficult to take out from food. It occurs in food in small amounts. We get the most vitamin D from fresh eel. Herring (preferably in oil) and salmon (cooked or baked, not fried) are another source. Vitamin D3 may also be taken from the yolks of chicken eggs and fish oil.

Quoted earlier prof. Roman S. Lorenc believes that just a proper diet is not enough to ensure an adequate level of vitamin D, hence the need for supplementation. "We would have to eat over 30 eggs every day to ensure appropriate level." - "Experts: almost every Pole should take vitamin D", PAP - Science in Poland, Zbigniew Wojtasiński, 12/07/2014.

From supplements, I may recommend Swanson vitamins and Puritan’s Pride, which offer vitamin D3 at 5000mg. Combinations of vitamin D3 and K2 in one tablet or drops are also available, as well as the ADEK vitamin complex. Vitamin D, as A and E, dissolves in fat. Therefore, it is recommended to take it an hour after a meal which will include animal fat.


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