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How Vitamin D Can Lower Influenza Risk

Influenza comes around every year in a slightly different form and has the ability to completely ruin a person’s life for a week or maybe even longer in some cases. While people who are at the most serious risk from it will usually take precautions in order to reduce either their risk of catching influenza or the severity of their symptoms if they do, most people feel that it is simply something they will have to deal with at some point.

What if I told you that was not actually the case though, and that a common nutrient most people eat on a daily basis could help to protect us from catching influenza if only we made sure to get enough of it each day? Well, that is exactly the case with vitamin D, as clinical studies have shown that keeping your vitamin D levels high enough can indeed lower your risk of catching influenza or experiencing symptoms.

Still don’t believe it? Well, in the following article, we will explain exactly how vitamin D can lower influenza risk, so in a few minutes, you surely will.

Table of Contents

What Is Vitamin D?

Vitamin D is an essential, fat-soluble vitamin also known as cholecalciferol and “the sunshine vitamin”. It is required in order for countless functions in the human body to take place, with clinical trials showing that the average person needs to consume at least 10 to 20 mcg of vitamin D per day in order for their body to function at an optimal level (1).

Widely available in both foods and supplements, upping your daily intake of vitamin D can produce a variety of health benefits, such as reducing the risk of influenza, improving bone, brain, heart, and immune system health and functions, energy and testosterone production and levels, male sexual health, blood sugar levels, muscle strength, and bone density, and helping combat depression and various other health issues.

In this article, we are going to focus on how vitamin D can lower influenza risk. For anyone interested in learning how any of its other health benefits are produced though, we have previously published two other articles that go into great detail on each of them, which you can read here and here.

What Is Influenza?

Influenza is a contagious respiratory illness that is more commonly known simply as the flu. Caused by a number of similar influenza viruses that infect the nose, throat, and sometimes the lungs, the flu can cause mild to severe symptoms and can sometimes even lead to serious complications, especially in young children, elderly people, and those with weakened immune systems or pre-existing health conditions.

The most common symptoms of influenza usually include fever, coughs, a sore throat, a runny or stuffy nose, body aches, chills, fatigue, headaches, and shortness of breath. In the more severe cases, the flu can lead to complications like pneumonia, dehydration, and the worsening of any existing medical conditions like asthma or heart disease (2).

Influenza is usually spread through droplets from coughing, sneezing, or talking, and it can also be spread by touching surfaces that have previously been contaminated with the virus. Vaccination is one of the best ways to prevent influenza, as flu vaccines are updated annually to protect against the most common strains. However, eating a healthy diet and taking certain supplements can also help your body fight it off and reduce the symptoms.

How Vitamin D Can Lower Influenza Risk

Boosts The Immune System

Most of the benefits that vitamin D offers when it comes to lowering the risk of influenza come from the fact that it is proven to boost the human immune system.

Vitamin D is great for immune system modulation as it helps to regulate the immune system by promoting the production of certain antimicrobial proteins. These proteins are a crucial part of the body’s first line of defense against various pathogens, which include viruses like the flu. One of the most beneficial proteins of this kind is cathelicidin, which has potent antiviral properties and can help fight off a wide variety of different infections.

Beyond modulating the immune system as a whole, vitamin D is then also particularly good at strengthening the immune response that it produces. This is due to the fact that vitamin D supports both the innate and adaptive immune systems. It helps to activate certain immune cells, such as T-cells and macrophages, which are vital for recognizing and attacking pathogens and helping the body fight off viruses, including the influenza virus (3).

Reduces Inflammation

Vitamin D is well-known to help reduce excessive inflammation, which is something that can occur with many respiratory infections like influenza. Excessive inflammation can lead to more severe symptoms and complications in people who have already contracted the virus, while also making people far more susceptible to catching it in the first place.

By modulating the body’s inflammatory response, vitamin D may therefore reduce both the risk of catching influenza in the first place and the severity of any flu symptoms that you experience if you do (4).

Prevents Low Vitamin D Levels

While this may seem self-explanatory to some, multiple studies have produced epidemiological evidence that demonstrates how individuals who suffer from low vitamin D levels are far more susceptible to both getting respiratory infections like the flu and developing more severe symptoms when they do. This can then also exacerbate many of the other issues that low vitamin D levels can cause, such as muscle and bone pain, weakness, tingling in the extremities, cramps, fatigue, and poor bone, joint, skin, and tooth health.

Additionally, certain studies have indicated that vitamin D supplementation during flu season could help to reduce the incidence of flu and other viral infections in most of the population, but it is particularly effective at doing so in people who have low vitamin D levels (5).