Six easy (and tasty) ways to up the immune-boosting power of your meals

Try these tips from a trio of dietitians

15 July 2021 - 10:03 By sanet oberholzer
You can easily up the vitamin D content of mushrooms by exposing them to sunlight for an hour before cooking them.
You can easily up the vitamin D content of mushrooms by exposing them to sunlight for an hour before cooking them.
Image: 123RF/nblxer

When cold and flu season and the Covid-19 pandemic collide, it's more important than ever to nourish your body with the immune-boosting foods it needs to fight back against infections.

Here, a trio of dietitians share tips on what to eat to help ensure your immune system is functioning optimally:


If you are deficient in vitamin D, the chances of having severe Covid-19 symptoms and complications are increased, explains registered dietitian Carly Seager of Intelihealth Dietitians in Johannesburg.

“Not only are mushrooms a natural source of vitamin D, but you can boost their vitamin D content by exposing them to sunlight for an hour before cooking them,” she says.

Other food-based sources of vitamin D include oily fish such as pilchards, trout and salmon as well as egg yolks.

Another way of increasing your vitamin D intake is to spend time in the sun. Seager recommends daily sun exposure of 10-30 minutes.


“Flavonoids are phytochemicals found in plant-based foods [which] act as antioxidants and have been shown to be beneficial in the fight against viral infections and thus boost the immune system,” explains Kgadi Moabelo, registered dietitian and spokesperson for the Association for Dietetics in SA (ADSA).

Moabelo says you can power up your meals by adding flavonoid-rich ingredients to them. For breakfast, she suggests adding blackberries and diced apples to cereals such as muesli and bran flakes, or stirring them into plain yoghurt. For lunch or dinner, add tomatoes and onions into stews and gravies, she says, and serve sides such as kale, red cabbage or salads containing lettuce and olives.


Turmeric contains a potent antioxidant known as curcumin, which is anti-inflammatory and immune supportive, says Seager. “Make sure to pair turmeric with black pepper and a ‘healthy’ fat such as olive or avocado oil for better curcumin absorption.”

You could add turmeric to soups, smoothies, curries or stews.


Selenium is a trace element and antioxidant that has immune supporting and anti-inflammatory properties.

Brazil nuts are a brilliant source of selenium.
Brazil nuts are a brilliant source of selenium.
Image: 123RF/highwaystarz

“Just two Brazil nuts per day will meet your recommended daily allowance (RDA) for selenium,” says Seager. “I recommend pairing these nuts with a serving of fruit such as berries or papaya as a snack, or adding them to a salad loaded with baby spinach, red pepper and tomatoes to further increase your antioxidant intake.”


According to Rosanne Lombard, a registered dietitian and ADSA spokesperson, gut microbiota (microorganisms) play a crucial role in supporting the immune function.

“This means that by making sure that your gut health is functioning optimally, your immune system will also be working as well as it can,” she says.

To give your gut a helping hand, Lombard recommends incorporating fibre-rich foods into your meals such as fruits, vegetables and whole grain carbohydrates like potatoes and sweet potatoes with the skin on, mealies, brown rice and bulgar wheat.

She also suggests limiting the amount of refined carbohydrates (think white flours, sweets and chocolates) you eat as these can disrupt the balance of the microbiota in the gut and therefore compromise immune function.


Vitamin C is a well-known antioxidant which supports the immune system and may decrease the duration of colds and flu. 

“Be wary, though of taking too much vitamin C over a prolonged period. Too much vitamin C through supplementation may increase the risk of developing kidney oxalate stones,” explains Seager.

How much is too much? More than 500mg of vitamin C per day, she says.

Eating ½ cup of chopped red pepper and 1 orange, or 1 cup of cooked broccoli and ½ cup of chopped strawberries per day will fulfil the adult RDA for vitamin C, Seager adds.