SINGAPORE - Hairdresser Catherine Jin panicked when she read about the recent rise in Covid-19 infections among children here.

The 36-year-old, who has two daughters aged 13 and 11, started stocking up on vitamin C supplements. "I don't know if it will help guard them against the virus, but it is worth a try to keep them healthy, especially during this period," she says.

More than 40 students and pupils from about 30 schools here have come down with Covid-19 in the past month.

The news is making administrative executive Rachna Kumar, 38, worry too. Recently, she started giving her daughter multivitamin gummies and also makes sure the seven-year-old drinks enough water and eats fruits and vegetables daily.

"I believe the type of food we eat is very important in helping us to maintain a healthy body, so I'm trying to cut down on takeaways and prepare healthier home-cooked meals," says Ms Kumar.

Experts The Straits Times spoke to say parents can help boost their children's immune system with a diet rich in antioxidants, such as vitamin C or zinc, to keep them healthy.

Mr Derrick Ong, founder and accredited dietitian at Eat Right Nutrition Consultancy & Clinic, says children may be more vulnerable to infections as their immune system is not fully developed.

A healthy diet helps equip them with the required nutrients for immune responses to promote recovery and build immunological memory to protect against future infections.

Mr Ong adds that maintaining a balanced and varied diet consisting of wholegrains, lean protein, fruits and vegetables, while limiting processed food and refined sugar, would help the immune system to function at its optimal level.

Ms Melanie Anthonysamy, who leads the nutrition team at digital health platform HealthifyMe, says children can take nuts and seeds such as almonds, walnuts, pumpkin seeds and flax seeds, as these contain nutrients like selenium and magnesium which help produce antibodies.

She also recommends lean meat such as chicken, as it is high in not just zinc, but also protein, which is the building block of immune cells.

Eggs are also good as they contain vitamin D, which can strengthen the immune system, she adds.

Dr Naras Lapsys, a consultant dietitian at The Wellness Clinic, says: "Children can often be picky eaters and are still discovering the types of food they like and dislike, so it is possible they may not be consuming as many food that are high in antioxidants, zinc and vitamin D."

Studies show that a deficiency in zinc and vitamin D can have a negative impact on immune function and health, he notes.

While sun exposure is the best source of vitamin D, food such as salmon and sardines are also good sources.

Parents can encourage their children to eat these food items by incorporating them into meals and snacks.

For example, Ms Anthonysamy says salmon can be cooked as nuggets or cutlets and offered to children as finger food.

Yogurt, which is packed with probiotics and good bacteria that fight and stop the build-up of bad bacteria, is also a good immune booster that can be consumed as a smoothie. Ms Anthonysamy recommends blending it with bananas or berries for breakfast or as a snack.

Eggs can be prepared as a simple egg sandwich or egg muffin.

To include yogurt, eggs and fruit in a delicious meal, Mr Ong suggests a wholesome pancake breakfast. This can be easily prepared by mixing one mashed ripe banana with two beaten eggs and cooking it in a non-stick pan. The dish can be topped with yogurt and decorated with your child's favourite fruit.

For a main meal, parents can include lean meat by preparing chicken soup with vegetables for lunch or dinner, says Ms Anthonysamy.

To boost their immunity, children can be also given chewable or gummy multivitamins.

Parents can consider getting a herbal immunity booster like elderberry extract in syrup from the pharmacy, notes Dr Mohana Rajakulendran, a consultant paediatrician at Parkway East Hospital.

She says parents should encourage their kids to adopt a healthy lifestyle by engaging them in exercise at home.

"They can follow YouTube videos on simple daily workouts or children's yoga, which are often animated and have music to capture kids' attention," she said.

If kids feel cooped up at home, parents can take them for a short walk at an uncrowded park. But Dr Mohana warns against going to playgrounds during this period, as these have surfaces known to spread viruses among children.

She also advises parents to keep pre-school children at home if possible, given the rise in Covid-19 cases in schools and learning centres.

"Pre-schoolers are an at-risk group as they may not be able to strictly keep to hygiene measures, and, moreover, those under the age of two are also not able to safely wear masks," she says.

She urges parents to seek medical attention for their kids early if they have symptoms of a respiratory illness such as a runny nose, sore throat or cough.

"It would be good to allow children to recover fully before sending them back to their pre-school or childcare centre as it is not uncommon for children to fall ill again soon after, as their immune system has not had the time to fully recover from the previous illness," says Dr Mohana.