Can foods high in vitamin C protect us from the flu & cold?

Can foods high in vitamin C protect us from the flu, cold, or coronaviruses?

You may have heard that vitamin C boosts the immune system. Is that true? Can we be protected from viruses, eating foods high in vitamin C?

Does vitamin C boost the immune system?

Vitamin C has powerful antioxidant activities.

Moreover, vitamin C reduces oxidative stress and inflammation effects (1).

Also, vitamin C enhances immune cell function. 

Most noteworthy, vitamin C supports the good function of the epithelial barrier (2). Epithelial barrier protects the body from pathogens of the environment.

So, vitamin C protects the body from environmental oxidative stress. Moreover, vitamin C help us sleep better!

Can vitamin C protect us from viruses?

The symptoms of the flu or the common cold may be fever, cough, runny nose, headache, muscle and joint pain, and sore throat.

Studies have shown that vitamin C may relieve, or even prevent the symptoms of the flu or the common cold.

Recommended vitamin C intake

But how much vitamin C do we need?

According to the National Institutes of Health, we need about 75-90 mg of vitamin C daily.

That’s for healthy people though.

Maybe we should consume more. Especially during the flu season.

Should we take vitamin C supplements?

According to studies, patients relieved of the symptoms of the flu and common cold, after taking vitamin C supplements.

Moreover, researchers gave patients a dose of 1000 mg of vitamin C, three times, daily.

Another study found that extra vitamin C supplementation benefited patients with the common cold. Even though, they were taking vitamin C supplements, before the onset of the disease.

Moreover, vitamin C can decrease the duration and severity of the common cold symptoms (3).

Most noteworthy, vitamin C has such powerful properties, that may affect pneumonia, as well. Three studies proved that vitamin C supplementation can significantly lower the incidence of pneumonia (3).

So, the scientific data has shown that adequate vitamin C levels affect the respiratory infections in humans (3).

Side effects of vitamin C supplementation

Vitamin C is a water-soluble vitamin. The body can’t store it. Therefore, vitamin C toxicity is unlikely to happen.

Likewise, scientists have given mega dosages of vitamin C to patients with severe health problems. They gave up to 100.000 mg of vitamin C to people with cancer. They didn’t observe any significant side effects.

So, a dosage of 1000 mg of vitamin C is pretty safe.

But, could we consume 1000 mg of vitamin C from food?

Foods rich in vitamin C

Firstly, better remember that only plants are good sources of vitamin C.

Many foods are rich in vitamin C.

For instance, strawberries, kiwi, papaya, broccoli, cauliflower, cantaloupe, cabbage, kale, peppers, garlic, tomatoes, and citrus fruits, are all high in vitamin C. See the whole list here.

Try to follow a whole food plant-based diet. Consuming 5 servings of fruits and vegetables a day with a glass of red wine can boost your immune system. Wine may prevent the flu and the common cold.


  1. Pan American Health Organization: Clinical trials on drug repositioning for COVID-19 treatment
  2. University of Otago: Vitamin C and Immune Function.
  3. University of Helsinki: Vitamin C and SARS coronavirus