Does Vitamin D Boost Your Immune System?

What Are the Best Sources of Vitamin D?

The connection between Vitamin D and the immune system is quite strong, as we will show you through scientific research. But before answering the question, does Vitamin D boost your immune system? it’s essential to explain what Vitamin D is and what the main sources of it are.

As a fat-soluble vitamin, it aids calcium absorption in the bones and promotes growth. It’s also been shown to aid in several other bodily functions, including the nervous system, circulation and digestion.

The Office of Dietary Supplements recommends most adults receive between 600 and 800 IU daily. HoweverFortunately, there are a lot of ways to make sure you get enough Vitamin D. 

This article will answer the question, does Vitamin D affect the immune system? It also looks at the relation between the sun and Vitamin D and examines several Vitamin D rich foods. As with any vital nutrient, if you are unable to get the daily recommended amount, you might prefer incorporating a Vitamin D supplement. But first, let’s look at how to get Vitamin D into your daily routine naturally.

Does the Sun Help Your Immune System?

There’s a reason Vitamin D is known as “the sunshine vitamin.” Spending a lot of time in the sun is a good way to receive Vitamin D. The skin hosts a particular form of cholesterol that becomes Vitamin D when exposed to UV-B radiation. Plus, studies show that Vitamin D from the sun might circulate through the body twice as long versus Vitamin D that comes from supplements and food.

However, several variables change how your body makes Vitamin D received from the sun. If you have darker skin, research suggests you might need to spend more time in the sun to produce Vitamin D. Additionally, as you age, Vitamin D production becomes less efficient, according to another study.

If you live close to the equator, you should be able to produce Vitamin D year-round. However, research shows that sun exposure decreases the further you move away from the equator.

If you want to receive Vitamin D from the sun, you need to carefully consider the clothing you wear. Some clothing and sunscreen will block the production of Vitamin D completely. While you want to protect your skin, it’s possible to get a good dose of Vitamin D without too much exposure.

How do you get Vitamin D if you don’t want to be in the sun? You can purchase a UV lamp that emits UV-B radiation. This form of treatment has been used for years to alleviate certain skin conditions, but recent research shows it’s also a valuable way to get a healthy dose of Vitamin D.

What Foods Have a Lot of Vitamin D?

As you look at the best sources of Vitamin D, you see that there’s a vast selection of healthy foods that will supply the recommended amount. However, there aren’t many foods that have Vitamin D naturally. 

Some fatty fishes include Vitamin D, as does beef liver, egg yolks, cheese and mushrooms. Aside from that, most Americans receive their Vitamin D intake from fortified foods.

As an example, most milk in the United States is fortified with 100IU/cup of milk. Most breakfast cereals also contain fortification. In addition, you can find some brands of yogurt, orange juice, margarine and plant milk that contain Vitamin D, but you should always read the labels to verify it.

So what foods contain Vitamin D? If you are hoping to balance out your diet and avoid taking supplements, we suggest you start with these Vitamin D foods:


3.5-ounces of this fatty fish contain 526 IU of Vitamin D. However, the amount varies based on whether you eat farmed or wild salmon. You can find higher levels – up to 1,300 IU per serving if you choose to eat wild-caught salmon instead. For a real treat, try honey garlic salmon for your next dinner. 


You may not think of these little fish as nutritional, but they are rich in Vitamin D. One can of sardines provides 177 IU of Vitamin D. Additionally, sardines provide Omega-3 fatty acids, Vitamin B-12, calcium and essential minerals to your diet. You can quickly turn this little fish into a sardine salad sandwich


Fresh Atlantic herring offers 216 IU of Vitamin D per 3.5-ounce serving. Herring also contains Omega-3 fatty acids, antioxidants, protein and Vitamin B-12. Some people choose to pickle the herring, but this might be too salty for your diet. Instead, opt for a grilled herring with peas, mint and Meyer lemon

Canned Tuna

Canned light tuna can offer 268 IU of Vitamin D with a 3.5-ounce serving. It’s also a good source of Vitamin K and niacin. However, canned tuna can also contain methylmercury, which could lead to health problems if you consume too much of it. If you plan to eat tuna, stick to light tuna and consume six ounces or less per week. For lunch, consider a Mediterranean tuna melt.

Egg Yolks

You don’t have to eat fish to get Vitamin D. Whole eggs are also quite nutritious, with the egg white providing protein and the yolk supplying 37 IU of Vitamin D. The level depends on the amount of sun exposure that the egg received and what the chickens were fed. We recommend choosing eggs from pasture-raised chickens that roam freely outside. Try egg-topped avocado toast for breakfast. 


It’s hard to find Vitamin D vegetables because it’s not found in most plants. However, mushrooms synthesize Vitamin D from UV light, just like the body does. Wild mushrooms can offer up to 2,300 IU per 3.5-ounce. If you are a vegetarian, you might enjoy soy-glazed tofu and mushrooms.


In America, cow’s milk is fortified with Vitamin D, but it also contains other nutrients. You will find a good source of riboflavin, calcium and phosphorus in a glass of milk. If you don’t drink cow’s milk, you can substitute it with plant-based milk and still receive many nutritional benefits — just not the same amount of Vitamin D. Consider drinking a fruit and milk smoothie to start your day. 

Orange Juice

A cup of fortified orange juice can provide as much as 100 IU of Vitamin D. It’s likely also fortified with calcium, which makes it a great alternative for people who don’t drink milk. Orange vinaigrette made with oranges makes an excellent topping for salads. 


Some instant oatmeal brands are also fortified with Vitamin D. You may even get as much as 54 to 136 IU of the vitamin, depending on what brand you choose. If you have a sweet tooth, you should enjoy making instant oatmeal packet cookies as a treat. 


Depending on the brand, you could get ten to twenty percent of your daily requirement of Vitamin D. However, a majority of fortified yogurts are also filled with sugar, so you want to read the labels carefully. Start your day with a fruit and yogurt smoothie to get several nutrients and vitamins into your body. 

Do Vitamin D Supplements Help Your Immune System?

There are far more Vitamin D benefits than you might expect. However, if you can’t get enough Vitamin D through food or sunshine, you should consider supplements, which will ensure you receive enough Vitamin D to not only support your immune system, but also your overall health.

Looking specifically at Vitamin D and immune system responses, there’s plenty of data to support the connection between the two. Research shows that Vitamin D provides both anti-inflammatory and immunoregulatory properties that activate the body’s defense systems.

In addition, the role of Vitamin D has been linked to reducing multiple sclerosis risk. Additionally, it could decrease the likelihood of developing heart disease. Vitamin D supplement benefits may also include enhancing the function of immune cells.

Does Taking Vitamin D Help During Cold and Flu Season?

Research also shows there’s a connection between Vitamin D and the flu. However, you shouldn’t take a high dose of Vitamin D for the flu without consulting a healthcare provider. More research is needed to determine whether or not Vitamin D is more effective than the flu vaccine.

Does Vitamin D help with colds? There is a connection between Vitamin D for colds. Studies suggest taking 4000 IE daily of Vitamin D might significantly reduce the chance of getting a cold. After seeing the importance of Vitamin D, it’s clear this nutrient should be included in every diet or vitamin regimen. 

Vitamin D and COVID-19

We’ve answered the questions, what are the benefits of Vitamin D? And what does Vitamin D do for the body? But, even though Vitamin D benefits the immune system, can it be helpful against COVID-19?

At this time, there is no coronavirus vaccine. However, we know Vitamin D deficiency can lead to suppressed immune function and an increased chance of respiratory illnesses, according to one study. Additionally, research shows Vitamin D may reduce mortality in older adults. Since that is the group most affected by COVID-19, it wouldn’t hurt for older adults to learn how to boost Vitamin D intake.

Understanding how the body gets Vitamin D and the effect of Vitamin D on the immune system can help determine whether or not a Vitamin D supplement is something to add to your nutritional regimen.

Vitamin D Deficiency Diseases List

Because Vitamin D boosts immune system performance, it’s extremely important to avoid any sort of deficiency. As far as what causes low Vitamin D, specifically, nutritional deficiencies generally stem from a lack of proper nutrition and poor lifestyle choices. If your regular intake is lower than what is recommended, you could suffer from Vitamin D deficiency symptoms over time.

According to the Office of Dietary Supplements, low Vitamin D symptoms could include:

  • Rickets
  • Osteomalacia
  • Bone pain
  • Muscle weakness
  • Cognitive impairment
  • Higher risk of cardiovascular disease

Those most at risk for Vitamin D deficiency and immune system suppression include:

  • People with little exposure to sunlight
  • Vegetarians
  • Vegans
  • Anyone eating a poor diet
  • People with darker skin, making it harder to synthesize Vitamin D

The connection between Vitamin D and the immune system is the solution to these problems. But in order to take advantage of that connection you need to learn how to increase Vitamin D levels.

Start by searching out good food sources of Vitamin D. And take advantage of the benefits of getting Vitamin D from the sun. Lastly, consider supplements. These three steps should keep you from experiencing any low Vitamin D and immune system problems.