November 29, 2021 9:00 pm

Alison Vickery

Vitamin C is a simple and effective antihistamine.

Not to mention a vital nutrient needed to perform many bodily functions. 

Here is what you need to know about Vitamin C and your health.



Vitamin C deficiency is synonymous with scurvy. However, from a histamine intolerance perspective, Vitamin C is a vital nutrient, and a deficiency can lead to:

Histamine intolerance

DAO deficiency

High blood histamine

High histamine neurotransmitters

Poor immune function, and

Exposure of cells to immune stimulation.


Other symptoms of a vitamin C deficiency are:

Low adrenaline and adrenal fatigue

Bleeding disorders

Low bone minerals


Poor exercise performance or intolerance

Hair corkscrew shape

Lesions in and around the mouth

Low oxytocin

Shortness of breath on exertion, and

Skin aging.


Vitamin C also recycles vitamin E, and its deficiency lowers vitamin E status, as they work synergistically.



Key Benefits

The key benefits of adequate vitamin C intake can be summarised in the following areas:

Improved Histamine RegulationVitamin C is a vital nutrient co-factor needed to regulate histamine.

Oxidative Stress Reduction – Vitamin C is a potent free radical scavenger that neutralizes oxidative stress, making it a vital nutrient that protects lipids, DNA, and RNA from free radical damage.

Collagen Health and Protection – Vitamin C plays a vital role in the maintenance and repair of collagenous tissues, including skin, bones, cartilage, ligaments, and tendons. It also protects against UV light-induced photodamage.

Improved Immune Function – Vitamin C is a vital nutrient needed by white blood cells, including neutrophils that fight infections.

Improved Cognitive Function – Vitamin C plays a vital role in cognitive function, including concentration and performance on tasks involving attention, focus, and working memory. Vitamin C also regulates and balances neurons and protects the brain from oxidative stress, linked to neuropsychiatric and neurodegenerative symptoms.

Genetic Regulation – Vitamin C is essential to protecting genes from environmental stressors.

Cardiovascular health – Vitamin C sufficiency reduces cardiovascular disease by supporting blood vessel integrity, reducing vascular free radical damage, and improving microcirculation.



Vitamin C Deficiencies

There are two root causes of vitamin C deficiencies:

A Poor Diet – low in vitamin C rich, fresh fruit and vegetables, as we cannot manufacture vitamin c. We must obtain it from our diet. 

Increased Demand – for vitamin C due to cellular stress from viruses, high levels of physical activity, physical illness, and exposure to toxins including ethanol, and especially cigarettes.

Vitamin C levels, therefore, are integral to health; the more chronic the condition, the higher the depletion.


Testing Vitamin C Levels

A simple blood test to measure plasma ascorbate will establish vitamin C status. 

In Australia, I use iMedical to evaluate run blood plasma levels. 

For the blood test to be reliable, the blood test should not only be fasting, and we should take no vitamin C for 12 hours prior.

I also like using the Vibrant Wellness Dried Spot Micronutrients Test. For around US$200, you can get a wide range of nutrient markers, and this test is available worldwide.



Restoring Vitamin C

Generally, restoring vitamin C levels starts with ensuring that our diet contains adequate fruits and vegetables.

However, additional food sources are typically needed when there is an exceptionally high need for vitamin C due to ill health 

Extremely high levels of Vitamin C are found in:

Kakadu Plum (Gubinge) – Kakadu plum is a native fruit of Australia with the highest concentration of Vitamin C in any food. Just 15g will provide 2g of Vitamin C. 

Camu Camu – Camu Camu is a native fruit of Peru. It has a high concentration of Vitamin C (second only to Kakadu Plum). Just 17g will provide 2g of Vitamin C, making it a substitute for Kakadu Plum. It has a consistency and taste similar to Kakadu Plum, so I tend to use one or the other.

Rosehips – contain less vitamin C (relative to Kakadu plum or Camu Camu). They also contain high antioxidants and flavonoids. This is also what tests well as a binder for high copper levels.  I have seen it dramatically reduce copper levels to a normal range.

Aloe Vera – while not strictly rich in vitamin C, it has been shown to boost gastric absorption of vitamin C by as much as 300%. As it’s also a mast-cell stabilizer, it makes sense to include this in the diet.



Vitamin C Supplementation

As a general rule, I also like to include a multivitamin with ascorbic acid as a protective step.

We can also use vitamin c therapeutically to help manage chronic conditions.

Here is a quick summary of current research findings for adults:

General health –  200 milligrams (if not obtained through dietary supplementation).

Histamine intolerance – 1 – 3 grams daily, with 2 grams a general recommendation.

Diabetes or a suppressed immune system – at least 6 grams a day.

Active bacterial, viral, flu, or UTI infections –  initial dosage of 3 grams, then 1 – 2 grams every hour for 6 – 8 hours.  

Mild COVID infections (natural or unnatural) –  initial dose of 3 grams, then 1 – 2 grams every hour for 6 – 8 hours, until symptoms subside. Once symptoms subside, take 8 – 12 grams daily. You will need this higher level for at least two weeks.

COVID infections (natural or unnatural), an initial dose of 3 – 5 grams, then 2 grams every 30 minutes, for 4 hours. If symptoms do not improve, take an additional 3 – 5 grams, then 2 grams every 30 minutes for 12 hours. If symptoms do not improve, take an additional 10 grams, then 3 – 5 grams every 30 minutes for 12 hours. Then follow the instructions for a mild COVID infection.

Frequent small intakes are much better than a single large daily dosage as Vitamin C is quickly utilized by the body.

If our gut health is particularly impaired, then liposomal Vitamin C or intravenous forms that bypass the gut barrier may be a better alternative.





Vitamin C is generally safe, with a few exceptions.

Hemochromatosis – vitamin c increases iron absorption and possibly iron-induced oxidative damage in individuals with hemochromatosis.

Oxalate intolerance – increases the risk of oxalate stones in individuals with oxalate intolerance or compromised kidneys.

Glucose 6-phosphate dehydrogenase deficiency – is a genetic disorder that can increase the risk of red blood cell issues.


Bowel Tolerance

Vitamin C is not toxic, but when consumed above the rate of intestinal absorption, it may cause diarrhea.

Bowel tolerance occasionally occurs as low as 4 grams per day but often takes more than 10 grams daily.

Diarrhea will cease upon withdrawal of the high dose, so vitamin C is above the upper limit.


histamine intolerance, mast cell activation, autoimmunity, Alison Vickery, Health, Australia



Along with zeolite, Vitamin C is one of my go-to remedies for histamine intolerance and restoring health.

Rather than reaching for an antihistamine designed to stop your body from responding, you may want to consider increasing your vitamin C intake and giving your body the raw materials it needs to work as designed.


To learn more about natural antihistamine alternatives that help with histamine intolerance, check out my blog post,  Natural Antihistamine.

Follow me on InstagramFacebook, and YouTube to continue the conversation.


Additional Reading

Johnston, C. S. (1996). The antihistamine action of ascorbic acid. In Sub-cellular Biochemistry (pp. 189-213). Springer US.

Hagel, Alexander F., et al. “Intravenous infusion of ascorbic acid decreases serum histamine concentrations in patients with allergic and non-allergic diseases.” Naunyn-Schmiedeberg’s archives of pharmacology 386.9 (2013): 789-793.

Jarish, R, Editor (2015). Histamine Intolerance: Histamine and Seasickness.

Ricardo Gonzalez Alvarez, Milagros Garcia Mesa, Ascorbic acid and pyridoxine in experimental anaphylaxis, Agents and Actions, April 1981, Volume 11, Issue 1-2, pp 89-93.

Nandi, B. K., et al. “Effect of ascorbic acid on detoxification of histamine under stress conditions.” Biochemical pharmacology 23.3 (1974): 643-647.

Oudemans-van Straaten, Heleen M., Angelique ME Spoelstra-de Man, and Monique C. de Waard. “Vitamin C revisited.” Critical care 18.4 (2014): 460.

How Vitamin C Works

Miranda-Massari, Jorge R., et al. “The Effects of Vitamin C on the Multiple Pathophysiological Stages of COVID-19.” Life 11.12 (2021): 1341.

Pehlivan, Fadime Eryılmaz. “Vitamin C: An antioxidant agent.” Vitamin C 2 (2017): 23-35.

Lenton, Kevin J., et al. “Vitamin C augments lymphocyte glutathione in subjects with ascorbate deficiency.” The American journal of clinical nutrition 77.1 (2003): 189-195.

Carpenter, Kenneth J. “The discovery of vitamin C.” Annals of nutrition and metabolism 61.3 (2012): 259-264.

Pullar, Juliet M., Anitra C. Carr, and Margreet CM Vissers. “The roles of vitamin C in skin health.” Nutrients 9.8 (2017): 866.

Malmir, Hanieh, Sakineh Shab-Bidar, and Kurosh Djafarian. “Vitamin C intake in relation to bone mineral density and risk of hip fracture and osteoporosis: A systematic review and meta-analysis of observational studies.” British Journal of Nutrition 119.8 (2018): 847-858.

Panush, R. S., et al. “Modulation of certain immunologic responses by vitamin C. III. Potentiation of in vitro and in vivo lymphocyte responses.” International journal for vitamin and nutrition research. Supplement= Internationale Zeitschrift fur Vitamin-und Ernahrungsforschung. Supplement 23 (1982): 35-47.

Elste, Volker, et al. “Emerging evidence on neutrophil motility supporting its usefulness to define vitamin C intake requirements.” Nutrients 9.5 (2017): 503.

Hemilä, Harri. “Vitamin C and infections.” Nutrients 9.4 (2017): 339.

Travica, Nikolaj, et al. “Plasma vitamin C concentrations and cognitive function: a cross-sectional study.” Frontiers in aging neuroscience (2019): 72.

Harrison, Fiona E., and James M. May. “Vitamin C function in the brain: vital role of the ascorbate transporter SVCT2.” Free Radical Biology and Medicine 46.6 (2009): 719-730.

Kocot, Joanna, et al. “Does vitamin C influence neurodegenerative diseases and psychiatric disorders?.” Nutrients 9.7 (2017): 659.  

Gillberg, Linn, et al. “Vitamin C–A new player in regulation of the cancer epigenome.” Seminars in cancer biology. Vol. 51. Academic Press, 2018.

Young, Juan I., Stephan Züchner, and Gaofeng Wang. “Regulation of the epigenome by vitamin C.” Annual review of nutrition 35 (2015): 545.

Mustafi, Sushmita, et al. “Vitamin C supplementation expands the therapeutic window of BETi for triple negative breast cancer.” EBioMedicine 43 (2019): 201-210.

Mustafi, Sushmita, et al. “Vitamin C Sensitizes Melanoma to BET InhibitorsVitamin C Improves the Response of Melanoma to BETi.” Cancer research 78.2 (2018): 572-583.

Pires, Ana S., et al. “Ascorbic acid chemosensitizes colorectal cancer cells and synergistically inhibits tumor growth.” Frontiers in physiology 9 (2018): 911.

May, James M., and Fiona E. Harrison. “Role of vitamin C in the function of the vascular endothelium.” Antioxidants & redox signaling 19.17 (2013): 2068-2083.

Ashor, Ammar W., et al. “Effect of vitamin C on endothelial function in health and disease: a systematic review and meta-analysis of randomised controlled trials.” Atherosclerosis 235.1 (2014): 9-20.

Juraschek, Stephen P., et al. “Effects of vitamin C supplementation on blood pressure: a meta-analysis of randomized controlled trials.” The American journal of clinical nutrition 95.5 (2012): 1079-1088.

Ellulu, Mohammed S., et al. “Effect of vitamin C on inflammation and metabolic markers in hypertensive and/or diabetic obese adults: a randomized controlled trial.” Drug design, development and therapy 9 (2015): 3405.

Basili, Stefania, et al. “Intravenous ascorbic acid infusion improves myocardial perfusion grade during elective percutaneous coronary intervention: relationship with oxidative stress markers.” JACC: Cardiovascular Interventions 3.2 (2010): 221-229.

Dingchao, H., et al. “The protective effects of high-dose ascorbic acid on myocardium against reperfusion injury during and after cardiopulmonary bypass.” The Thoracic and Cardiovascular Surgeon 42.05 (1994): 276-278.

Schleicher, Rosemary L., et al. “Serum vitamin C and the prevalence of vitamin C deficiency in the United States: 2003–2004 National Health and Nutrition Examination Survey (NHANES).” The American journal of clinical nutrition 90.5 (2009): 1252-1263.

Nishikawa, Fumie, et al. “Ascorbate metabolism in harvested broccoli.” Journal of Experimental Botany 54.392 (2003): 2439-2448.

Sapei, Lanny, and Lie Hwa. “Study on the kinetics of vitamin C degradation in fresh strawberry juices.” Procedia Chemistry 9 (2014): 62-68.

Li, Yi, and Herb E. Schellhorn. “New developments and novel therapeutic perspectives for vitamin C.” The Journal of nutrition 137.10 (2007): 2171-2184.

Davis, Janelle L., et al. “Liposomal-encapsulated ascorbic acid: Influence on vitamin C bioavailability and capacity to protect against ischemia-reperfusion injury.” Nutrition and metabolic insights 9 (2016): NMI-S39764.