Vitamin D, a fat-soluble vitamin, plays many critical roles in your body.
This nutrient is particularly important for immune system health. Many people wonder if supplementing with vitamin D might help lower the risk of contracting COVID-19.
COVID-19 is not curable. However, you can prevent it from spreading by taking preventive measures such as proper hygiene and physical distancing.
Research has shown that vitamin D intake can protect you from respiratory illness and help maintain a healthy immune system.
Recent research indicated that patients with COVID-19 had a lower risk of death and adverse outcomes if they had adequate vitamin D ( 1Trusted source).
This article will explain how vitamin D can affect immune health and how supplementing this nutrient could help prevent respiratory problems.
What does vitamin D do to your immune system?
Vitamin D is essential for the proper functioning of your immune system, which is your body’s first-line defense against disease and infection.
Vitamin B1 plays an important role in the promotion of immune response. It is both anti-inflammatories as well as immunoregulatory and plays a critical role in activating immune system defenses ( 2Trusted Source).
Vitamin D has been shown to increase immune function, including T cells and macrophages. This protects your body from pathogens ( 3Trusted source).
Vitamin D is essential for immune function. Low levels have been linked to increased susceptibility of infection, disease and immune-related disorders ( 4Trusted Source).
Low vitamin D levels can lead to increased risks of developing respiratory diseases such as tuberculosis and asthma.
Additionally, vitamin-D deficiency has also been shown to cause decreased lung function which can affect your body’s ability fight respiratory infections ( 9Trusted Source, 10Trusted Source).
Can take vitamin D to protect against COVID-19?
There is currently no treatment or cure for COVID-19. Very few studies have examined the effects of vitamin D supplements on the risk of contracting SARS-CoV-2.
A recent study found that patients hospitalized with COVID-19 have a lower risk of death and adverse clinical outcomes if their blood levels of 25-hydroxyvitamin D are at least 30ng/mL.
Analyzing hospital data from 235 patients suffering from COVID-19 was possible.
Patients over 40 years old were 51.5% more likely to experience adverse outcomes such as becoming unconscious, hypoxia and death if they had adequate vitamin D levels. (1Trusted Source).
However, studies from other sources have also shown that vitamin D deficiencies can cause problems in the immune system and increase your chance of developing serious respiratory diseases ( 11Trusted source).
Some studies also show that vitamin D supplements may increase immune response and protect against all forms of respiratory infection.
Recent research that involved 11,321 individuals from 14 countries showed that vitamin D supplementation reduced the risk of acute respiratory infection (ARI) in both people with adequate and deficient levels.
The study found that vitamin D supplements reduce the likelihood of developing at least one ARI by 12%. Low vitamin D levels were most protective ( 12Trusted source).
The review also found that vitamin D supplements are most effective in protecting against ARI when taken every day or weekly in small amounts ( 13Trusted source).
Vitamin D supplements also reduce mortality among older adults who are at the greatest risk for developing respiratory diseases like COVID-19 ( 14Trusted Source).
Vitamin D deficiency can also increase a process called the “cytokine storm” ( 15Trusted source).
The immune system is a major component of cytokines, which are proteins. They have anti-inflammatory and pro-inflammatory properties and can play an important role in protecting against disease and infection ( 16Trusted source, 17Trusted source).
Under certain conditions, however, cytokines may also cause tissue damage.
Cytokine storm is the uncontrolled release of pro-inflammatory cytokines in response to infection and other factors. The excessive and dysregulated release of cytokines can cause severe tissue damage, and increase disease severity and progression ( 18Trusted source).
It’s actually a major cause of multiple organ failure and acute Respir distress syndrome (ARDS) as well as a significant factor in the severity and progression of COVID-19 ( 18Trusted Source ).
Patients with COVID-19 severe cases have been shown to produce large amounts of cytokines, including interleukin-1 and interleukin-6, ( 19Trusted source).
Vitamin D deficiencies have been linked to decreased immune function and increased cytokine storm.
Researchers believe that severe COVID-19 complications may be increased by vitamin D deficiencies. Vitamin D supplementation may also reduce complications due to cytokine storms, uncontrolled inflammation, and other complications in COVID-19 patients ( 20Trusted source, 21).
Multiple clinical trials are currently being conducted to determine the effects of vitamin supplementation (at doses up to 200,000 IU) on people with COVID-19 ( 20Trusted Source and 22).
Although research is ongoing in this area, it’s important that you understand that taking supplemental Vitamin D alone won’t protect against COVID-19.
Vitamin D deficiency can increase your vulnerability to infection and other diseases by affecting immune function.
This is particularly concerning given the fact that many people are deficient in vitamin D, especially those who are older and most at risk for developing COVID-19-related complications ( 23Trusted Source).
It’s a smart idea to have your doctor test your vitamin D levels in order to find out if you are deficient in this vital nutrient. This is especially important in winter.
You can supplement with between 1,000 and 4,000 IU of Vitamin D per day depending on your blood level. To reach their optimal levels, people with low blood sugar levels may need to take higher doses ( 24Trusted source).
Although there are many recommendations about the optimal vitamin D level, experts generally agree that it is between 30-60ng/mL (75-150nmol/L) ( 25, Trusted Source and 26TrustedSource).