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Make sure to get enough vitamin C to prevent and fight infections

Make sure to get enough vitamin C to prevent and fight infectionsNowadays, fruit, potatoes, and vegetables in general contain very little vitamin C, and the majority of people fail to eat the recommended amount of these foods, in the first place. Unhealthy diets and lack of vitamin C increase the risk of colds, influenza, and other infections, simply because the immune system consumes large amounts of vitamin C in connection with the first explosive attacks that prevent virus from causing an infection. Vitamin C also has an important role in battling infections and preventing them from dragging on and leading to complications such as bronchitis or pneumonia.

During the winter period, many people catch a cold or the flu, and there is a lot of focus on vitamin D as a source of prevention. However, we also need vitamin C, as this nutrient has a number of anti-viral properties and helps the immune system fight infections in different ways. Vitamin C is also known as ascorbic acid, and is a nutrient that most mammals are able to produce on their own. It is only humans, anthropoids, and certain other species that have lost this ability as a result of evolution. Because vitamin C is water-soluble, it does not get stored in the body, which is why we need to consume it regularly. In that connection, it is important to bear in mind that our need for the nutrient increases in situations with infections and various types of stress.

Did you know that...

  • the largest concentration of vitamin C is found in the white blood cells?
  • the concentration of vitamin C can increase ten-fold during an infection?
  • vitamin C is destroyed by light, heating, overboiling, deepfreezing, preservation, and winter storage of fruit and vegetables                                                              

The non-specific (innate) immune system should be able to handle most infections without us noticing anything

Vitamin C increases the number and effectivity of the around 500 billion white blood cells that work around the clock throughout the entire body. There are particularly many white blood cells in our airways, and they need vitamin C to protect us against airborne pathogens such as cold germs and influenza virus.
The immune system is divided in two types with different kinds of white blood cells. The innate, non-specific immune system is our “storm troops” that handle most infections without us even noticing it. The non-specific immune system also includes some signaling proteins called cytokines. The most important cytokine is interferon.

Vitamin C and interferon both have central anti-viral properties

Interferons are produced by virus-infected cells. The word interferon is related to “interfere” that means to be or create a hindrance or an obstacle. Interferons work by preventing virus from reproducing inside cells. This is kind of like a factory worker pushing the emergency button to stop the conveyor belt when something goes wrong. Studies of so-called Gulo mice that are unable to produce vitamin C show that vitamin C supplementation has anti-viral effects by stimulating interferon production during the early stages of an infection, especially with influenza. Interferons are also able to attract white blood cells that function as storm troops. That way, the immune defense works from different angles.

Proteins tackle most infections

Vitamin C boosts the production of interferon that has several anti-viral effects. It turns out that 90% of bacteria injected into laboratory animals are killed by proteins from the non-specific (innate) immune defense.

Storm troops fire with free radicals with help from vitamin C

The moment we get an infection, our storm troops of white blood cells swiftly absorb a generous amount of oxygen that is converted into free radicals, which are fired off like lethal missiles to destroy bacteria and other potentially harmful compounds. This process, also known as the “respiratory burst reaction”, is virtually a respiratory explosion.
During these rapid frontal attacks, large quantities of vitamin C are needed to help the white blood cells fire off free radicals against the microbes. Scientists, studying a specific type of white blood cells called neutrophil granulocytes, have found levels of vitamin C to be ten times higher than normal, which says something about the magnitude of the explosive processes and the role of vitamin C.
Vitamin C stimulates the production of free radicals targeted at the intruding microbes. At the same time, vitamin C is a powerful antioxidant that protects the surrounding cells and tissues against the damage caused by the free radicals. At the first signs of an infection, it may be a good idea to take extra supplements of selenium and zinc, as these minerals also contribute to the explosive immune processes and function as antioxidants at the same time.

Free radicals and antioxidants

Free radicals are a byproduct of our own respiration. They increase in number during infections, stress, ageing processes, poisoning, exposure to tobacco smoke, and radiation. Free radicals are aggressive molecules that attack and damage cell membranes and bacteria. The only thing that can protect us against free radicals is various kinds of antioxidants. The diet contributes with the vitamins A, C, and E plus selenium, zinc, and different plant compounds.

Vitamin C can prevent complications

In situations where the non-specific immune system and the storm troops are unable to deal with the problems, the specific immune defense is activated. However, it takes a few days to mobilize it. Once this happens, we normally become noticeably ill. What we feel is not the microbes as such but the immune-triggered release of cytokines and other active compounds.
It is therefore highly important to have well-functioning storm troops that can effectively reject any type of contamination.
Vitamin C cannot treat a cold or a bout of the flu, once the virus has gained a foothold and you have a runny nose and sore throat. Still, the vitamin, which also strengthens the specific immune defense, contributes to faster recovery and prevents subsequent infections such as bronchitis, middle ear infection, and pneumonia. Such infections typically occur when our resistance is low, and bacteria from the natural microflora in the throat spread to areas where they normally don’t belong

Vitamin C is effective against many virus infections

In 2005, Orthomolecular Medicine News Service (a non-profit scientific information service) wrote that vitamin C is effective for treating bird flu. Numerous studies show that vitamin C is effective for treating all kinds of infectious diseases, including different types of influenza, encephalitis, and measles. In complicated cases, large doses of vitamin C have been administered intravenously to rapidly provide the immune system with a larger supply of the vitamin to make it function more effectively.

Subclinical scurvy is a sign of vitamin C deficiency

A tendency to bruise easily, bleeding gums, nosebleed, and poor wound healing are signs of “subclinical scurvy”. Full-blown scurvy is the final consequence of vitamin C deficiency with lethal internal hemorrhaging, fatigue, joint pain, allergies, low stress threshold, and several other problems.
The fact that smaller doses of vitamin C are able to prevent scurvy, however, is no guarantee that the body is properly supplied with the nutrient. Some scientists compare vitamin C to a water-soluble hormone with countless essential functions.

The need for vitamin C is especially great in connection with

  • Physical and mental stress
  • Beginning infections
  • Poor immune defense and chronic disease
  • A tendency to bruise easily, bleed from the gums, or other signs of “subclinical scurvy”
  • Detoxification and working with harmful substances
  • Abuse of sugar, tobacco, alcohol and other stimulants, and junk-food
  • The use of birth control pills, aspirin, painkillers, and antibiotics
  • Pregnancy and lactation                                                                                                                                                                       

Vitamin C sources and RI (reference intake)

Vitamin C is mainly found in fruit, berries, and vegetables like cabbage, bell pepper, horseradish, spinach, garlic, ginger, and other herbs. Fresh produce contains the highest amount of vitamin C. The reference intake for vitamin C is 80 mg and prevents scurvy, which is the classical vitamin C deficiency syndrome. Nonetheless, the RI level is far below the amounts of vitamin C, which animals are able to produce. In fact, they can double or even triple their production of the vitamin in situations with stress or infections.

Vitamin C and supplements

It is generally a good idea to consume a diet that is rich in vitamin C because such a diet is bound to contribute with other essential nutrients, as well. When it comes to choosing supplements, it is normally best to stick with non-acidic vitamin C that is gentle towards the stomach lining. A supplement with 500-750 mg of vitamin C corresponds with the amount of vitamin C found in 10-15 oranges or 50-75 apples.
At the initial signs of an infection, it is possible to boost the immune defense by taking a high dosage of non-acidic vitamin C several times a day. It is important, however, to avoid mega-dosages on a daily basis, as this may eventually displace copper, another nutrient that is also important for proper immune functioning.

It is a good idea…

have strong, non-acidic vitamin C at home and to bring it along on travels as a way of giving the immune system a quick boost in situations where an infection is on its way.                  

Remember to wash your hands and make to follow other rules of hygiene to avoid unnecessary contamination


Lester Packer, Jürgen Fuchs. Vitamin C in Health and Disease. University of California

Kim Y et al. Vitamin C Is an Essential Factor on the Anti-viral Immune Responses through the Production of Interferon-α/β at the Initial stage of influenza A Virus (H3N2) Infection. Immune Netw. 2013

Orthomolecular Medicine News Service October 26, 2005

H. Clay Gorton, Kelly Jarvis. The effectiveness of vitamin C in preventing and relieving the symptoms of virus-induces respiratory infections. Journal of Manipulative and Physiological Therapeutics 1999

Frederik R. Klenner. Clinical Guide to the use of Vitamin C

Pernille Lund. Immunforsvarets nye ABC. Hovedland. 2012

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