Supporting Your Immune System When You Are Immunocompromised: COVID-19 Edition

Amid the first wave of the COVID-19 pandemic, I posted a blog Should You Take Immune Boosters If You Are Immunocompromised?

It's been ten months of ups and downs. As someone who is immunocompromised and inadvertently came into close contact with someone who tested positive for COVID-19, I know the general stress and anxiety that come with flu season and rising COVID-19 cases in Canada and across the globe.

Here is an update on a few vitamins, minerals, supplements and foods that can help support your immune system:

Vitamin D

Vitamin D, the sunshine vitamin, helps to maintain your immune system, but can be hard to come by in Canada during the cold and flu season. This amazing vitamin also helps to regulate immune function and reduce inflammation!

Images source: canva.com

What is new?

There is promising research on vitamin D concerning the prevention and treatment of COVID-19. A recent study looked at 489 individuals who received a COVID-19 test and had their vitamin D levels assessed the previous year. Researchers found that 19% of vitamin D-deficient individuals tested positive for COVID-19, compared with only 12% of patients who tested positive but had adequate vitamin D levels.

Another study found a positive correlation between living in northern countries (where vitamin D absorption from sunlight is lower) and an increased risk of death from COVID-19. A study conducted in Spain found that among 216 COVID-19 patients, 82.2% had vitamin D deficiency. These patients were more likely to have longer hospital stays.

No recommendations have been made regarding vitamin D levels and COVID-19, but research has shown that adequate levels are essential to support the immune system's proper functioning.

Osteoporosis Canada recommends that those taking medications affecting vitamin D absorption should supplement with 800 – 2,000 IU daily. Make sure you are purchasing vitamin D3 (cholecalciferol) supplements in oil or oil-based capsules for optimal absorption.

Always speak to your healthcare provider for advice that best fits you. For instance, my rheumatologist suggested taking 3000-4000 IU per day, which is just below the upper limit for daily intake.

Zinc

When it comes to fighting colds, Zinc gets a lot of attention for a good reason!

Your immune system relies on Zinc for optimal functioning, and it may help shorten the duration of colds if taken at the onset of symptoms. It also helps with tissue development and helps to support cartilage regeneration, both are very important for those with inflammatory arthritis.

Supplementation is usually not needed if you eat a varied diet that includes high-protein foods such as seafood, legumes or lean meats.

However, studies have shown that people with Rheumatoid Arthritis may have lower zinc levels. Additionally, people with short bowel syndrome and inflammatory bowel disease (i.e. Crohn’s Disease) are at risk of Zinc deficiency due to malabsorption.

So how much zinc should you take?

You may have heard of the UL (aka the Tolerable Upper Intake Level), it is the highest level of a nutrient that can be ingested each day without having any adverse effects for most healthy individuals.

For Zinc, the UL is 20mg per day for healthy adults, so mega-doses of Zinc over long periods should be avoided. Taking more than 50mg/day can not only cause toxicity, but it can also block the absorption of copper.

Copper is an essential mineral with anti-inflammatory effects, and low levels may lead to irreversible anemia. Speak to your healthcare provider to decide what dose is right for you

Regarding zinc and COVID-19, a study in Spain looked at 249 hospitalized COVID-19 patients. The researchers noted that patients with low blood zinc levels had more difficulty recovering from the illness than those with normal levels. They also identified increased mortality. No recommendation has been set based on these results.

Omega-3

Omega-3 fatty acids provide excellent support for your immune system during the cold and flu season, and they can help to reduce inflammation.

The best dietary sources of Omega-3s are fatty fish such as salmon, tuna, and sardines, or plant sources such as walnuts, soybeans, and flaxseeds.

If you are concerned that you may not be consuming enough through your regular diet, speak to your healthcare provider to find out which Omega-3 supplements could be of most benefit to you.

In vitro and in vivo experiments have shown that omega-3 fatty acid supplementation can reduce the severity of COVID-19 but that was only with small doses, high doses need further research.

They noted that the reduction in severity is because eicosapentaenoic acid EPA and docosahexaenoic acid DHA have anti-inflammatory effects. When they are oxidized by enzymes, they help synthesize less inflammatory eicosanoids and lipid mediators, which reduce inflammation caused by infections and viruses.

Another study used imaging techniques to study the spike protein of the COVID-19 virus.

The spike protein can bind to different cells in the body and connects ACE2 to ACE2, allowing the virus to infect them. The study found that linoleic acid (i.e., omega-6) is present in the spike protein.

The study suggests that linoleic acid supplementation can help bind linoleic acid to the spike protein pocket and the linoleic signalling axis, which may provide a therapeutic intervention for COVID-19 patients.

Spirulina:

Spirulina. Image source: canva.com

Spirulina is a type of blue-green algae. It is a popular "superfood" that the media loves to talk about! It is a cyanobacterium that has a 60% protein content.

It is also a good source of beta-carotene, many vitamins/minerals (i.e., B vitamins, vitamin E, manganese, zinc, copper, iron and selenium) and gamma-linoleic acid. Due to the presence of phycocyanin, there are antioxidant benefits to fight oxidative damage from free radicals, too.

Moreover, it is promoted to support the immune system, improve cholesterol levels, manage diabetes, support kidney function, and lower blood pressure. There is little scientific evidence to back up any of these claims, though. Spirulina is available in capsules, tablets and powder forms, but it is not regulated by the FDA.

In animal and in vitro studies, spirulina appears to increase the levels of antibodies, proteins that fight off infection, and other immune cells. No human studies to date, though. However, a clinical trial involving humans that examined Chlorella (another blue-green alga) did not boost the body's immune response to a flu vaccine.

Thus, research on spirulina and the human immune system is not yet detailed.

In-vitro and rodent data had shown that spirulina may support the initial defence against RNA viruses such as coronaviruses (including SARS).

The research suggests that interferons (proteins produced and released in response to germs) increase after consuming spirulina. Nonetheless, there is insufficient research to reach a conclusive decision on whether spirulina reduces the risk of contracting COVID-19. It may boost the immune system, which is not desirable in autoimmune diseases.

Spirulina blue-green algae appear to be well-tolerated. It can absorb heavy metals, such as mercury, lead, arsenic, aluminum, and others. As always, seek advice from your health care provider if this supplement is right for you and check its source.

Don't let your guard down! Your best defence this cold and flu season, and particularly during the COVID-19 pandemic, is to continue practicing physical distancing, frequent hand hygiene, and staying home when ill. Strive to maintain a healthy, active lifestyle whenever possible.

Special thanks to 4th-year nutrition students at Ryerson University Cheryl Anderson, who assisted with the research for the original post Should You Take Immune Boosters If You Are Immunocompromised? and Emily Malfara who assisted with the COVID-19 update.

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