Strong immunity has never been so important. No matter where in the world you live, it’s vital that you focus your attention on boosting your immune system and keeping as well as possible.

Your immune system is a complex network of cells, organs, tissues, and processes that work together to protect you from bacteria and viruses.

One of the best ways to keep your immune system functioning properly is to eat a whole, nutritious diet. That means lots of brightly-colored fruits and vegetables, fermented foods, and immune-boosting herbs.

Supplements are also a helpful and convenient means of supporting immunity. Of course, it’s difficult to know which supplements are truly beneficial, so I’ve narrowed it down to the top five!

1. Probiotics

Probiotics are live beneficial bacteria that live in your gut and help your body to carry out many different functions every day. Around 70 percent of your immune system cells reside in the walls of your gut, which means those bacteria play a major role in your immunity.

Taking probiotic supplements is a great way to maintain the health of the ‘good’ microorganisms that make up your gut microbiome. These good bacteria help your body to digest and absorb nutrients from the food you eat, supplying the vitamins and minerals needed by various systems.

Research has shown that probiotics support immunity by helping your body produce antimicrobial substances such as bacteriocins. Probiotics regulate the pH in your gut, creating an environment where pathogenic bacteria and viruses struggle to survive. They also help to ward off harmful bacteria and yeasts by preventing them from attaching to your intestinal membrane.

Probiotic supplementation has been found to significantly reduce the risk of developing upper respiratory infections and flu-like symptoms in patients with a temperature higher than 38 °C.

Look for a product that contains multiple strains and a high colony-forming unit count (CFU).

Some immune-boosting strains to look for include Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus paracasei, along with Bifidobacterium longum and Bifidobacterium breve. These strains have been clinically proven to help prevent harmful bacteria and viruses from adhering to the gastrointestinal tract while also restoring immune markers and supporting the intestinal barrier. (1)

When buying a probiotic, don’t forget the delivery system that it uses. Most probiotics only get a tiny proportion of their bacteria to your gut because their capsules are destroyed by your stomach acid. Look for a probiotic that uses time-release tablets as these are currently the most effective way of getting those immune-boosting microbes safely to your gut.

A good example is the probiotic from Balance ONE. It has a great set of immune-boosting strains and uses time-release tables that release those bacteria into your gut over 8-10 hours.

2. Vitamin C

Vitamin C is both an essential micronutrient and a potent antioxidant. It supports your body’s defenses by optimizing various cellular functions of both the innate and adaptive immune systems. It also accumulates in phagocytic cells, such as neutrophils, supporting several important immune functions. It helps with chemotaxis – the movement of vital organisms around the body – and phagocytosis, the ‘engulfing’ of harmful pathogens.

Vitamin C also has a part in killing harmful microbes by helping to boost the differentiation and proliferation of B- and T-cells (important immune cells). This keeps your immune defenses primed and ready for attack. It also helps your body absorb iron, form red blood cells, and create folic acid.

Studies have shown that regular supplementation with vitamin C can help in both preventing and treating respiratory and systemic infections (2). In addition, Vitamin C is a valuable antioxidant that helps to ward off reactive oxygen species generated by your environment, diet, stress, alcohol.

Pure Encapsulations Hypoallergenic Vitamin C is an excellent choice because it is made from ingredients suitable for even the most sensitive digestive systems. This vitamin C is free from GMOs and additives such as magnesium stearate, gluten, hydrogenated fat, artificial sweeteners and colors.

3. Zinc

Zinc plays a role in several aspects of the immune system, from your skin to the way your lymphocytes work. It’s required for healthy growth, the healing of wounds, and the metabolism of many essential nutrients required for everyday health.

Zinc is vital for the healthy development and function of your immune cells, including neutrophils and natural killer cells. Low levels of zinc may result in weakened immune function, particularly regarding the production of T cells, B cells, and cytokines. These particular immune cells are crucial for healthy defenses against invading bacteria and viruses.

Some studies have shown that zinc lozenges may reduce the duration of a cold by around 1-2 days (3). Other zinc supplements may also reduce the number of upper respiratory infections in children.

In addition, zinc has major roles in basic cellular functions such as DNA replication, RNA transcription, cell division, and cell activation. Zinc is also an important antioxidant and helps to stabilize membranes.

Now Foods Zinc Picolinate is a well-tolerated vegan source of zinc to support the body’s needs. Zinc aids in hundreds of enzymatic reactions in the body as well as proper RNA/DNA synthesis.

4. Vitamin D

Vitamin D plays a major role in the optimal functioning of your immune system. The Vitamin D receptor is expressed on your immune cells, which means it is intricately involved in the response of your innate and adaptive immune systems. Vitamin D was even used to treat infections such as tuberculosis before antibiotics were available.

Studies have shown that Vitamin D deficiency is prevalent in many autoimmune diseases, including multiple sclerosis, TIDM, and SLE. The high association between vitamin D levels and autoimmunity has led to it being recommended for the prevention and protection from autoimmune diseases.

Inadequate levels of vitamin D have also been associated with a higher risk of infections, while supplementation can reduce the risk of those infections and speed recovery (4). The National Institute of Health warned that low vitamin D levels can increase susceptibility to frequent colds and flu.

A good choice for your Vitamin D is Doctor’s Best Vitamin D3 5,000 IU. It supplies five times the recommended minimum daily intake of D3, which research suggests is more likely to ensure optimal immunity.

5. Cod liver oil

Cod liver oil is a rich source of vitamins A, D, and omega-3 fatty acids. It not only provides important nutrients for your cells and bones but for your immune system, too.

Vitamin A is essential for a healthy immune system, bone growth, eye health and cellular growth. It’s also an important antioxidant that helps to ward off harmful free radicals that can damage cells.

Vitamin D is vital for maintaining the health of your immune system cells and plays an important part in activating your defense system.

Recent research has shown that omega-3 fatty acids EPA and DHA may enhance the function of immune B cells. A study published in the Journal of Leukocyte Biology showed that these omega 3 fatty acids enhance the activity of white blood cells known as B cells.

The study found that DHA-enriched fish oil enhanced both B cell activation and select antibody production, which may improve immune responses associated with pathogen clearance. At the same time, the fatty acids help to dampen down the overall inflammatory response. When mice were fed with DHA, they showed significantly higher plasma levels of important cytokines involved in fighting off disease (5).

Choose a cod liver oil product that contains omega-rich oil from fish caught in pure waters. A good example is Nordic Naturals Arctic Cod Liver Oil. This is one of the best cod liver sources of Omega-3, with a total of 750 mg including DHA and EPA.