During the winter period, many of us have runny noses and some may end up in bed with a bout of flu. Now is the time to prime your immune system by getting all those vitamins and minerals that your diet is not always able to provide you. That way you can ward off germs and avoid unnecessary sick days. But what effect does vitamin C, vitamin D, selenium, and zinc have on the immune system’s different “troops”, and how much do we need?
The immune defense’s task is to fight virus and bacteria using its different troops that work around the clock.
The non-specific (innate) immune system compares to storm troops. It consists of different proteins, most of which are white blood cells. The non-specific immune defense fights the majority of infectious germs without us even noticing.
The specific (adaptive) immune system that consists of T and B-lymphocytes comes to our rescue in situations where the non-specific defense falls short. In such cases, we feel unwell, and it is the signaling substances of the immune defense in particular that cause these unpleasant symptoms.
Powerful storm troops prevent infection
Now is the time to boost the storm troops of our non-specific immune system so we avoid catching colds and influenza from our surroundings. When the immune system fights a cold or a flu, it drains our resources. If the immune system is weak, there is a risk that bacteria from the natural microflora in our oral cavity or throat spread, causing bronchitis, throat infection, or infections of the sinuses, ears, and lungs. It is especially complicated when older, immune-compromised people contract pneumonia. Here, vitamin C plays a particularly important role together with vitamin D, selenium, and zinc. They all help us avoid infections and subsequent complications.
We need a lot of vitamin C for our white blood cells and interferons
The concentration of vitamin C in the white blood cells is 80 times greater than in the red blood cells. In fact, vitamin C has the capacity to increase the number and effectivity of white blood cells
In our respiratory tract, we have particularly many white blood cells (macrophages) that protect against airborne germs. These macrophages are highly dependent on vitamin C, especially when a virus goes around or the body is about to develop an infection.
Vitamin C is also important for the body’s production if interferons, which are different types of signaling substances that increase the communication between cells and help prevent virus from replicating inside the cells.
Remember plenty of vitamin C for prevention and warding off infections
Generally speaking, vitamin C is extremely important for the explosive immune attacks that are intended to pummel virus and bacteria and prevent them from causing disease.
Most animals are able to synthesize their own vitamin C from glucose (blood sugar). In the case of infection, animals step up their vitamin C manyfold in order to strengthen their immune system. Humans cannot synthesize vitamin C and therefore we depend on the vitamin from our diets or from supplements. The reference intake (RI) level for adults is 80 mg, but this appears to be too little to provide optimal protection against infections.
By taking a high-dosed (non-acidic) vitamin C supplement within hours of detecting the first signs of a sore throat, it is possible to nip a virus infection in the bud. This, essentially, corresponds to the increased vitamin C production in animals that have contracted an infection.
Vitamin C – doing the math
It is important to get lots of vitamin C from fruit and other good sources. However, just so you know, you need to consume around 13 oranges or 60 apples to get the same amount of vitamin C as you would get from taking a tablet with 750 mg of non-acidic ascorbic acid
Different studies of vitamin C and infections
According to an article published in 2017 in the journal, Nutrients, 148 animal studies show that vitamin C can mitigate or prevent altogether infections caused by virus, bacteria, and protozoa. Vitamin C supplements can reduce by 50% the number of colds in physically active people and even reduce the duration of the cold. Two controlled studies have found that cold symptoms last fewer days with oral ingestion of 6-8 grams of vitamin C daily. Three controlled studies have demonstrated that vitamin C prevents pneumonia, which is often seen as a complication in connection with colds and influenza.
Vitamin C’s ability to prevent and fight cold infections remains unclear, as studies have differed in their results. This may be because the preventative dose was too low, or because supplementation was initiated too late after discovering the infection. The inconsistent study results could also be a result of an overconsumption of sugar and fast carbohydrates.
Lack of effect in studies of vitamin C and immune defense may be
Why sugar blocks the uptake of vitamin C in the body
Insulin conveys both glucose (blood sugar) and vitamin C into our cells using the same channels. In other words, a bottleneck may occur in situations where there is too much glucose in the blood. Consuming fast carbohydrates such as sugar, soft drinks, white flour, pizza, and chips produces a blood sugar hike that can make it difficult for vitamin C to enter the cells (including the white blood cells).
The inadequate vitamin C absorption in white blood cells may even explain why diabetics, who often have elevated blood sugar levels, are more vulnerable to infections than others are. The problem is also seen with insulin resistance, which is when the insulin is too weak to channel enough sugar into the cells, and blood sugar levels are permanently elevated.
Two researchers, Fred Ottoboni and Alice Ottoboni, have described this problem and suggest consuming at least one gram of vitamin C (or more) daily in the case of an infection. It is also advisable to avoid altogether or limit ones intake of fast carbohydrates in order to maintain stable blood sugar levels and to prevent the blood sugar from rising too rapidly.
Did you know that vitamin C is important for our production of connective tissue, and that a vitamin C deficiency makes us more prone to bruising, bleeding gums, nosebleeds, poor wound healing in general, and frequent infections?
Infections increase oxidative stress – but vitamin C is a protective antioxidant
Whenever there is an imbalance between free radicals and antioxidants, a state known as oxidative stress occurs. When white blood cells from the body’s storm troops are activated before attacking virus-infected cells or bacteria, they start by absorbing enormous amounts of oxygen and converting it into free radicals. These free radicals are like destructive missiles. The process is called “respiratory burst”. Figuratively speaking, it is as if the white blood cells take a deep breath before they start firing free radicals at the enemy.
Studies show that the blood cells need large quantities of vitamin C and selenium in order to deliver a fast and accurate attack. However, because free radicals are highly aggressive molecules that can also damage healthy cells and cause potentially dangerous chain reactions, vitamin C and selenium also serve as protective antioxidants that defend healthy cells and tissues against oxidative stress. Vitamin C and selenium therefore have many different roles in the immune system.
Lack of vitamin C and poor utilization of the nutrient are caused by
Choose non-acidic vitamin C
Salts of ascorbic acid are called ascorbates and are used in non-acidic supplement that contain sodium ascorbate or calcium ascorbate. Non-acidic supplements are gentler towards the gastrointestinal mucosa.
Overdosing – side effects
Symptoms of an overdose are rare because excess vitamin C is excreted in the urine. Consumption of more than two grams daily (especially as pure ascorbic acid) may cause diarrhea, nausea, bladder irritations, and an increased risk of kidney stones. Therefore, it is best to take non-acidic vitamin C.
Also remember to wash your hands frequently to avoid infections
An overview of the immune system
|Defense||Non-specific (innate)||Specific (adaptive)|
|Functions as||Storm troops, messengers and trash collector.
|Special troops that develop immunity.
Mature after birth.
|Mechanical and biological||Skin and mucosa.
|Specific compounds in the ”acute” phase||Interferon
|Direct cellular destruction||Dendritic cells
|T cells. Primarily responsible for virus, fungi, and abnormal cells.
B cells and antibodies. Primarily responsible for bacteria and toxins.
Hemilä H. Vitamin C and Infections. Nutrients 2017
Fred Ottoboni , Alice Ottoboni. Ascorbic Acid and the Immune System. Journal of Orthomolecular Medicine 2005
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 Virus (H3N2) Infection. Immune Netw. 2013
Pernille Lund. Immunforsvarets nye ABC. Hovedland 2012