Supporting the Body With Vitamin C During Times of High Stress, Immune Challenges, and Mold Exposure

by Dr. Susan Tanner, MD

Our immune systems are complicated and diverse.  It would be impossible to give credit to one single thing for strengthening or enhancing immune system function, but the studies are deep and comprehensive when it comes to the role that Vitamin C plays.  In fact, most of us are first introduced to the power of Vitamin C in elementary school history class. We learn that sailors and explorers at sea for months at a time often developed bleeding, puffy gums.  Quite by accident, the sailors and explorers who then began eating limes, lemons, and oranges while exploring tropical areas had complete resolution of these symptoms. Hence, the nickname, “limey” for sailors was initiated, and thus begins the first of many anecdotal-type reports of the salutatory function of citrus in health and disease.

The health benefits of consuming citrus fruits are not where Vitamin C education ended. Through the ages, Vitamin C in many forms–citrus, corn, and palm leaf–has been used medicinally to treat everything from skin lesions to acute infections with success in many cases.  In the 20th century, much more research and testing were done that then helped explain just how and why Vitamin C aids so many health conditions and prevents others.

How Does Vitamin C Work to Benefit the Human Body?

As humans, we are unable to synthesize or produce Vitamin C on our own, due to the lack of certain protein catalysts.  For that reason, all Vitamin C that we take in is in the form of foods or nutritional supplements. Some of the recommendations for oral supplementation of Vitamin C are from Linus Pauling, Ph.D.  (Dr. Pauling was a brilliant chemist and one of the first to win two undivided Nobel prizes.  One was in molecular biochemistry, and that work contributed to Watson and Crick’s breakthrough in the discovery of the DNA double helix.)  Through Pauling’s pioneering work in Vitamin C research we learned much about how this nutrient works, some ways of which are outlined below:

  • It increases the production of white blood cells, which can both prevent and treat infections. Both B and T lymphocytes are shown to increase in number and efficiency when Vitamin C is given.


  • Vitamin C is a powerful antioxidant. When the human body is bombarded, as we all are, by various environmental pollutants such as mold and mycotoxins, chemicals, heavy metals, chronic illnesses, and viruses, organ systems may suffer the consequences of oxidative stress, or “rusting”.  A powerful electron donor biochemically, Vitamin C helps to mitigate the impact of these pollutants.  (Note: Using Vitamin C does NOT take the place, however, of cleaning the air that you breathe or eating healthy foods! It should be taken more to mitigate the damage you cannot prevent or to boost the body’s ability to repair the damage that has already occurred.)


  • Collagen is increased by the use of Vitamin C. This leads to more resilient and stronger skin, tendons, cartilage, and other connective tissues. This also contributes to helping the body to heal and repair itself.


  • Studies have shown that Vitamin C helps to reduce inflammatory cytokines, which are released in the presence of allergies and severe infections. This has been of particular interest of late in studying the activity of COVID-19. The most severely ill patients are those in whom these inflammatory cytokines cannot be controlled.  High-dose Vitamin C has been added to the protocol in treating these ill patients.  Taking Vitamin C preventively may do exactly that; prevent the formation of these cytokines and help lessen disease severity, as well as common allergy expression.


  • In both smokers and those exposed to second-hand smoke, Vitamin C levels are greatly reduced due to the effects of nicotine. Supplementation with Vitamin C has been associated with decreased development of COPD, or emphysema.


  • Aging of skin and wrinkles are measures of oxidative stress on the skin. Remember, the skin is not a cover, it is a living and active organ, in fact, the largest in the body.  What you see on your outside may well be reflective of what is going on inside.  Again, Vitamin C comes to the rescue to salvage these organ systems.  Additionally, Vitamin C adds to the barrier function of the skin to decrease the entry of infectious bacteria.


  • A decrease in respiratory compromise in pneumonia in hospitalized patients has been noted with Vitamin C supplementation. The sickest of these patients had the lowest blood levels of Vitamin C.


  • Restoration of severe adrenal gland fatigue. Adrenal glands have the highest concentration of Vitamin C in the body. Even though it is a water-soluble vitamin and what your body doesn’t use or need is excreted in the urine, a very small amount is stored in the adrenal gland. This is because the adrenal glands need this vitamin to function properly and make hormones (like cortisol) so that the body can cope with stress. During stress, your body burns up many times the daily requirement of Vitamin C. As stressful events increase, the need for many nutrients, but especially Vitamin C also increases.


  • Vitamin C can be used to prevent and help in treating infection in diabetic patients. When blood sugar levels are not controlled, oxidative reactions in the body are also magnified.

These are only a few of the many ways that Vitamin C has been found to be extremely helpful.  I would suggest if you are interested in more, simply search Vitamin C and immune system function, and there will be more studies than you can read, but the more that you do read, the more you will become convinced that we all need this essential vitamin and, in some cases, large doses should be given.

With lots of information often comes lots of questions. In anticipation of that, I will go ahead and answer those I hear the most frequently:

Are There Individuals Who Should Not Take Vitamin C?

As mentioned above, Vitamin C is an essential vitamin, we all need it.  That said, there is a genetic condition called G6PD deficiency.  People with this condition should not take over 2 grams of Vitamin C daily as it can cause red blood cell damage.  But bear in mind, most do not ever take anywhere near this much.  In cases such as certain environmental or chronic illnesses in which more would be recommended, the blood test for G6PD deficiency is done first.

What is a Good Dose of Vitamin C to take on an Ongoing Basis?

Most adults can handle 1-2 grams daily just fine.  It is available in chewable form, powders, pills, and capsules. In the case of acute viral illness, more is recommended, even up to 5-6 grams.

Can You Overdose on Vitamin C?

The most common reaction to too much Vitamin C is upset stomach and diarrhea, but this is usually due to taking a tremendous amount.   If you want to step up your Vitamin C level, my suggestion is to start with 2 grams and work up slowly from there.  This can be done more than one time a day, and in fact, is preferable to be in divided doses rather than all in one dose.

What Type of Vitamin C is Best?

This is quite individual.  The most common type of Vitamin C available is actually made from corn.  If you have a corn allergy, then another form is preferable. My patients with multiple allergies and sensitivities usually do best on a sago palm form of Vitamin C.   Additionally, if one has a very sensitive GI system, then a buffered form of Vitamin C may be helpful.  This reduces the acidity of the C such that there is less chance of stomach upset with larger doses.   Liposomal Vitamin C is also a great option for some.  This is where Vitamin C is emulsified into an oil or fat. This may allow the C to be released more slowly into the system so less needs to be taken at a time.  For instance, 1000 mg of Vitamin C in liposomal form has as much antioxidant potential as 4 grams of regular Vitamin C.  The downside is the cost, which is considerably more, and the availability is limited as there are not that many brands, so it is harder to find.

What About Vitamin C and Mold Illness? Would Taking It Help Me Recover?

As outlined before in the list of the beneficial ways in which Vitamin C works in the body, you will notice that many of the health issues this essential nutrient prevents and helps are also ones that many mold patients suffer from. So, while there is no one universal remedy for any illness or disease, I do believe that supplementing with Vitamin C can lessen some of the extreme symptoms from toxic stress, inflammation, and immune system suppression that occurs when mold is in the picture. In fact, Vitamin C does many things all at once that most other supplements alone cannot—it helps the body to recover and fight infection; it helps regulate hormone production and secretion by supporting the adrenals and pituitary gland; it helps with energy production at the cellular level; it helps the body to mobilize and remove toxins; it can mitigate the histamine response from mold allergy; it also helps to counteract the build-up of toxins in the liver. Considering Vitamin C’s current use to mitigate the cytokine storm caused by COVID-19, it may come as no surprise that it can also be used to dampen the chronic inflammatory response syndrome (CIRS) that arises when the body is under siege from significant or prolonged exposure to mold and mycotoxins. The free radical scavenging activity of Vitamin C acts throughout the body, including the mucus membranes of the lungs. In this way, Vitamin C can protect the lungs against both the oxidative stress caused by an infection, like COVID-19 and inhaled triggers from the environment, like mold.

Supplement Recommendations

In conclusion, I feel that anyone can and does benefit from Vitamin C supplementation.  Certainly, we want to include foods rich in Vitamin C in our diets, but getting the amounts needed, especially to mitigate certain health conditions requires levels that are more than can be consumed safely.

Some brands that I like are:

Ecological Formulas Vitamin C Powder, from Sago Palm

Thorne Labs Buffered Vitamin C Powder

Klaire Labs Vitamin C 1000 mg tablets

Pure Encapsulations Vitamin C–They make many forms and types.

(All of these are available through my practitioner page on Wellevate. )

For liposomal Vitamin C, I prefer the NuMedica liquid.

(This is available on using code 40568)

CitriDrops Dietary Supplement is the final product I will touch on and recommend, not as a traditional Vitamin C supplement, but as a concentrated, efficient, and effective citrus extract. While Vitamin C and flavonoids contained in the product function as antioxidants, there are additional compounds in CitriDrops that have antiseptic, anti-rheumatic, antiviral, antibacterial, and anti-fungal properties as well. It must be diluted before use but is a natural pH alkalizer with no known toxicity or side effects.

(This is available from Micro Balance Health Products.)

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