Boost your immune system with vitamin D

We introduce the role of vitamin D while boosting your immune system; the best vitamin D sources and tips to raise vitamin D level.


Boost your immune system with vitamin D

Every autumn, you see your social channels flooded with articles and information about why it is important to boost your immune system, mostly to take care of yourself during the upcoming colder months, when your body is prone to respiratory diseases such as the flu and the regular common cold. But this year, paying extra attention to your immune system is important, as the global pandemic is on the rise and the cold months enable spreading the virus at a higher rate.

Vitamin D plays an important role in boosting your immune system and in this article we explain everything about it.

What is vitamin D and why do you need it?

Vitamin D is a type of vitamins that belongs in the fat-soluble category. It promotes the absorption of calcium, supports bone growth, maintains healthy teeth and it is indispensable when it comes to a healthy immune system.

Vitamins are nutrients that are not produced by the body by itself, so they need to be sourced from food or nutritional supplements, although the body can produce vitamin D thanks to sun exposure.

How does the body produce vitamin D?

The human body is capable of producing its own vitamin D from the sun, meaning that a couple of hours per week under the sunlight should be a great source to keep optimum vitamin D levels. On top of that, certain foods and supplements also support providing vitamin D, while also stimulating the body to produce its own.

What are D-vitamins? (D2, D3)

Vitamin D is more than one vitamin, it is a group of different nutrients with similar chemical structure, in which you can also find vitamins D2 and D3, and both contribute to increase your total levels of vitamin D.

From these two, vitamin D3 is formed in your skin when it is exposed to sunlight and it is also sourced from fatty animal foods. Vitamin D2 comes from plants and it is less productive when it comes to raising your vitamin D levels.

How much vitamin D should be consumed?

The recommended intake of vitamin D varies according to the age of the person, but an overall estimation recommends 400 IU (10 mcg) for infants between 0 and 12 months old, 600 IU (15 mcg) for children and teens between 1 and 18 years old, 600 IU (15 mcg) for adults up to 70 years old, and 800 IU (20mcg) for adults over 70 years.

Although bare skin exposed to the sun for 5 to 10 minutes, 2 or 3 times a week, can be enough for the body to produce enough vitamin D, the body will break it down quickly, meaning it is constantly needed to be replenished; specially in Winter when the sun exposure is limited.

5 symptoms of low vitamin D level

1. Getting sick often: As one of the most important roles vitamin D plays in your body is maintaining a strong immune system, low levels of vitamin D often mean that you are more likely to get sick and catch simple viruses and infections.

Basic diseases like the flu can be a sign of low levels of vitamin D, and different studies have shown how vitamin D deficiency is liked to respiratory problems such as regular colds, bronchitis and pneumonia.

2. Feeling fatigued and tired: It is no surprise that it is more difficult to get out of bed during the winter, and it is not just because it is too cold outside of the blanket. Reduced sun exposure and lower levels of vitamin D are linked with lack of energy and exhaustion. If your diet and sleeping patterns are normal and you still feel lacking energy, vitamin D deficiency could be the problem, which can be easily be prevented by taking vitamin D supplementation.

3. Bone, back and muscle pain: Vitamins D helps maintain bone and teeth healthy in many ways, specially given its contribution to the absorption of calcium by the body. Low levels of vitamin D are often evidenced by bone pain and lower back pain. If you are an adult over 30 and are already feeling that lower back pain, it is especially important to keep track of your vitamin D intake.

Hair loss

4. Hair loss: Regular hair loss is a normal aspect for the body, but if is happening at a rapid pace, you might want to check your vitamin D levels with your doctor, especially for women. Hair loss and alopecia areata might be signs of vitamin D deficiency in women.

5. Feeling depressed: Just like vitamin D is linked to your energy levels, it is also associated with your mood. Some studies have found that vitamin D intake helps to improve depression, including the regular one that happens during the colder and darker months.

How does vitamin D affect the immune system?

The role of vitamin D in maintaining a healthy immune system is very important, but also complicated. Vitamin D increases the function of immune cells, including T cells and macrophages, which protect the body from pathogens. However, our defences must be perfectly balanced. If stimulation is too high, autoimmune diseases may develop. Contrariwise, frequent infections may occur in the absence of immune system activity.

Low levels of vitamin D cause our immune system to be out of balance, which is why we are prone to various diseases. As explained, its deficiency has been shown to be associated with frequent respiratory infections such as the flu, pneumonia and bronchitis. A recent survey of 11,321 people from 14 countries showed that vitamin D supplementation reduced the risk of acute respiratory infections in both groups: those who were deficient and those who had normal levels.

Vitamin D deficiency is a risk factor for the development of some autoimmune diseases, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), type 1 diabetes mellitus, multiple sclerosis, inflammatory bowel disease and Hashimoto's disease. Current research shows that vitamin D levels of 30 ng / ml or less increase the risk of developing autoimmune disease or slow recovery.

How to raise vitamin D level?

1. Spend time in sunlight

Did you know there is a connection between cholesterol and vitamin D? When human’s bare skin is exposed to direct sunlight, the UVB (ultraviolet B) rays hit the cholesterol in the skin, enabling the synthesis of vitamin D. Sun exposure is the best source to keep up with vitamin D levels, just 5-10 minutes of direct sun exposure, 2 or 3 times a week, are enough for you to rip off the benefits and boost your immune system. For a more efficient production of vitamin D, the best time for sun exposure is around midday.


2. Consume fatty fish, seafood and mushroom

The best food sources of vitamin D are:

  • Salmon: Wild salmon contains about 988 IU of vitamin D per serving, while farmed salmon contains 250 IU, on average. That’s 165% and 42% of the RDI, respectively.

  • Herring and sardines: Herring contains 1,628 IU of vitamin D per 3.5-ounce (100-gram) serving. Pickled herring, sardines and other fatty fish, such as halibut and mackerel, are also good sources.

  • Canned tuna: Canned tuna contains 236 IU of vitamin D per serving. Choose light tuna and eat 6 ounces (170 grams) or less per week to prevent methyl mercury buildup.

  • Cod liver oil: Cod liver oil contains 450 IU of vitamin D per teaspoon (4.9 ml), or 75% of the RDI. It is also high in other nutrients, such as vitamin A and omega-3 fatty acids.

  • Egg yolks: One large egg yolk (17g) contains 37 IU of vitamin D, 5% of the DV.

  • Mushrooms: Mushrooms grown under UV light, including Chestnut, Baby Chestnut and Portobello, contain 1IU of vitamin D per 18g. Studies have found that even sliced and dried mushrooms soar in vitamin D if placed outdoors under the sun.

3. Take vitamin D supplement

  1. Vitamin D3: A dietary supplement containing 60 tablets of vitamin D, with each tablet providing 2000 IU.  Take 1 tablet daily with a large glass of water.

  2. Vitamin D3 drink powder: Lemon flavored dietary supplement beverage powder with sweeteners containing 10 IU of vitamin D3 per serving (5g). Mix 1 serving powder drink with 100 ml water by using a shaker and drink once a day.


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