Dear readers,

As a nutrition student/researcher, it is my job to recognize how eating behaviors influence our daily lives. It isn’t always clear, but necessary to understand that diet plays a huge role in overall health and wellness. It’s important to acknowledge that patterns in our own diet may affect the likelihood of complications of COVID-19 along with other illnesses. This pandemic is far from over, despite some states gradually opening back up.

In times like these, it’s easy to fall into unhealthy habits. Often times stress, lack of normal routine, or even just having easier access to unhealthy snacks is enough to pull us in a direction we aren’t super happy to go.

Simple diet changes can greatly improve emotional and physical health. Sometimes, we don’t realize how much of an impact micronutrients can have.

To avoid falling short in any major nutrients, remember that they can keep you feeling your best. Even if you don’t realize it, a deficiency of any essential nutrients may have a huge impact on your overall health, and leave you feeling even worse. An easy way to get a good variety of nutrients is by making sure you are eating a colorful diet rich in fruits, vegetables and whole foods. The American population tends to lack nutrients such as iron, calcium, and vitamin D.

I’ll be discussing how vitamin D can affect the complication rates of COVID-19. But first, I’ll have to get you familiar with what vitamin D is, where it comes from and what to do if you aren’t getting enough of it.

key points

  • vitamin D assists in immune health and function. [1]
  • vitamin D has been shown to protect against acute respiratory infections. [2, 4]
  • areas with higher cases of vitamin D supplementation due to less natural sunlight report lower COVID complications. [3, 2-7]

Vitamin D is essential for bodily functions including the absorption of calcium and phosphorus for healthy bone growth, the maintenance of a strong immune system and muscular movement.

It is recommended by the RDA that adults get 600 IU to 2,000 IU per day. Most Americans are actually deficient in vitamin D and have no idea. Most likely because it isn’t found in many foods consumed in the typical American diet.

Vitamin D is a nonessential nutrient meaning that it can be synthesized by the body through the absorption of UV or UVB rays. This involves going outside and getting plenty of sun. It can be hard to get the daily recommended intake of vitamin D through sunlight alone especially if you live in an area where it isn’t sunny or warm enough to enjoy outdoor activities.

In cases like these, vitamin D requirements can also be fulfilled by eating certain foods. Vitamin D is found in foods such as fatty fish (including tuna, mackerel and salmon), fish liver oils, egg yolks and grain and dairy products fortified with vitamin D.

A simple blood test will identify if you aren’t getting enough of this vitamin. However, there are some common symptoms to allow a quick prediction as to whether or not you are sufficient in vitamin D. If you are lacking vitamin D, you may experience symptoms such as:

  • general fatigue
  • malaise
  • bone pain
  • muscle pain and weakness
  • mood changes
  • depression

In children, a lack of vitamin D may be easier to identify because it will likely affect the development of their bones. Children with a vitamin D deficiency tend to have soft bones, which can lead to bowed legs, short stature or frequent bone fractures. In children, this deficiency will likely be caught by a pediatrician before symptoms reach this level of severity.

If you are experiencing one or more of these symptoms and you think it may be related to a vitamin D deficiency, there are some easy ways to incorporate more into your diet. For example, choosing fortified cereals and dairy products rather than those that do not contain the extra vitamin boost, is a simple and easy way to improve your vitamin D levels. Fatty fish is also a great option that pairs nicely with green vegetables and citrus.

Supplementation is also a great option if you aren’t so open to diet changes, or if your diet is already rich in these foods but you are still lacking vitamin D. You can get vitamin D supplement over the counter, or if you’d prefer, fish oil tablets are another over the counter option. However, because these drugs are offered over the counter, it is important to be sure you aren’t taking too much of any supplements, as this can also have an adverse effect on your health.

1. vitamin D assists in immune health and function

Your immune system is responsible for finding and attacking foreign invaders. If a virus is found, your body will produce antibodies so that if that virus ever enters your body again, it can be destroyed before you get sick. COVID antibodies can be tested for and tell you whether or not you have had COVID-19 or another coronavirus in the past.

Vitamin D plays a huge role in immune health and function. This is one of the many reasons that this vitamin is crucial to reducing complications associated with COVID-19. When you are suffering from a deficiency of vitamin D, it is not uncommon to experience getting sick more often. Usually, this means more incidences of the common cold, but it can be more serious, depending on the strength of the immune system and exposure to more serious infections.

A strong immune system could make a huge difference in the duration of the novel coronavirus, along with the severity of the symptoms. In order to keep your immune system functioning at its highest level, it is important to keep up with proper nutrients and follow the WHO guidelines to avoid contracting the virus.

2. vitamin D has been shown to protect against acute respiratory infections

An acute respiratory infection is defined by an infection that suddenly inhibits the ability to breathe normally. Generally, they start as viral infections. COVID-19 is an example of an acute respiratory infection because it does impair lung function.

Unfortunately, lung issues tend to have several comorbidities. This is one of the many reasons that COVID has had a more negative effect on those with underlying lung issues (such as asthma), obesity (in which lung volume is impaired), smokers and older adults. Lung health can be significantly improved by positive changes to diet and exercise. Adults who get 60 minutes of cardiac exercise a day, report lower rates of lung infections.

Vitamin D has been used previously to treat these types of infections, making it likely that this vitamin will have a similar effect on the novel coronavirus. It has been reported that those with the recommended daily intake of vitamin D suffer from less acute respiratory infections, suggesting that vitamin D can in fact prevent these infections completely or significantly lessen the severity of the symptoms.

3. areas with higher cases of vitamin D supplementation due to less natural sunlight report lower COVID complications

As mentioned previously, vitamin D supplementation may be necessary in cases where diet just isn’t cutting it or sunlight exposure is limited. Therefore, the parts of the world that get less natural sunlight, such as northern Europe where the weather tends to hover more on the side of cloudy and rainy, also have higher rates of vitamin D supplementation.

Our bodies are only able to synthesize vitamin D if there is the necessary exposure to UV rays. The body is able to use these rays to maintain the minimum vitamin D recommendations. If the proper amount of UV exposure cannot be met, supplements become a valuable option.

In relation to COVID-19, the areas that have less natural sunlight are also showing lower rates of COVID complications. It is hypothesized that this is due to the consequential increase of vitamin D supplementation. Those who are taking this vitamin as a supplement are ensuring that they are receiving the recommended dose. This suggests that vitamin D may reduce the complications associated with COVID-19, resulting in a lower death rate.

This also offers one possible explanation for why COVID-19 death rates are slowing as the weather is warming. Although the warm weather has not been proven to slow the spread of the virus, people are getting outside more. More time off of work, means less time to go on walks or even sunbathe, just as the weather is getting nice.

While diet may not always be the most advanced treatment method. It also shouldn’t be overlooked. It is a great way to prevent and in some cases reduce the severity of a multitude of diseases. The easiest way to keep your body healthy, is simply by watching what you eat.

Tracing all the way back to the agricultural revolution, nutrition as a science has been referenced to have the ability to treat ailments. This holistic approach isn’t the most popular, but it does come with a significant backing in the chemical and biological sciences. Even before we knew what we know today about why each macro and micronutrient is vital to our health, it was clear that certain foods had the ability to make people feel better.

Health weighs heavily on personal choice, and one of the many choices is what goes into your mouth. The more micronutrient-balanced your diet is, the higher your potential for a long and healthy living.

articles referenced

[1] Vitamin D linked to low virus death rate, study finds: New COVID-19 research finds relationship in data from 20 European countries. (n.d.). ScienceDaily. Retrieved June 10, 2020, from

[2] Vitamin D levels appear to play role in COVID-19 mortality rates: Patients with severe deficiency are twice as likely to experience major complications. (n.d.). ScienceDaily. Retrieved June 10, 2020, from

[3] Vitamin D determines severity in COVID-19 so government advice needs to change, experts urge: Researchers point to changes in government advice in Wales, England and Scotland. (n.d.). ScienceDaily. Retrieved June 10, 2020, from