Are kids supplements worth the cost?

Why supplements for sleep and eye health may not be the answer to your parenting prayers.

Child staring at smartphone screen at night.

Worried your child is spending too much time in front of a screen or having trouble sleeping? Supplement manufacturers have you in their sights.

For about $20, you can pick up a bottle of pills claiming to help your kid get a good night’s sleep by “promoting calm, relaxation and helping switch off a busy mind”. If you’re worried about screen time, there are supplements that state they’ll protect your child’s eyes from “excessive exposure to blue light”.

We put their claims under the spotlight.

“Blue light protection” claims

GoHealthy Screen Time iProtect ($22.99)

GoHealthy Screen Time iProtect.
GoHealthy Screen Time iProtect.


“The Lutemax [lutein and zeaxanthin] 2020 blend acts as nature’s sunglasses to help filter and protect against the damaging effects of blue light during screen exposure.”

Main ingredients

Beta-carotene, Lutemax (lutein and zeaxanthin) and zinc.

Radiance Kids Eye and Blue Light Defence ($21.90)

Radiance Kids Eye and Blue Light Defence.
Radiance Kids Eye and Blue Light Defence.


“Digital devices emit blue light which is widely thought to cause eyestrain and contribute to premature aging of the eye. As children’s eyes are still developing, research suggests excessive exposure to the blue light emitted from these devices can affect children’s vision.”

Main ingredients

Lutein, vitamin E and betacarotene.

What's the evidence?

GoHealthy’s Screen Time iProtect and Radiance Kids Eye and Blue Light Defence claim they’ll help protect young eyes from damage done by the blue light emitted from screens, such as smartphones, TVs and computers.

However, New Zealand Association of Optometrists councillor Andrew Sangster said there have been “no specific studies that indicate that ‘real world’ blue light exposure from devices causes harm”.

The 2018 Blue Light Aotearoa report, published by the Royal Society, stated that although kids’ eyes receive more blue light than adults’, more research was needed to show whether this increased exposure was damaging.

Carotenoids and beta-carotene

Your eye has three carotenoids – lutein, zeaxanthin and meso-zeaxanthin – which have the job of filtering out blue light and keeping the cells healthy.

Both supplements include carotenoids, along with vitamin E (Radiance) and zinc (GoHealthy), which clinical trials have shown can improve visual function in adults with macular degeneration. However, there haven’t been any studies done on children’s vision.

Mr Sangster warns you can’t extrapolate studies done on adults and assume the results automatically apply to children. “There have been no specific studies to confirm that [supplements are] either necessary or beneficial,” he said.

Both supplements also contain beta-carotene, which the body converts into vitamin A. Some clinical studies have shown a link between taking beta-carotene supplements and an increased risk in lung cancer in those who smoke. The Cancer Society recommends you get beta-carotene from your diet. It’s readily available in fruit, vegetables and whole grains.

You can get lutein and zeaxanthin in your diet, too. Green leafy vegetables and corn are good sources.

“Calm and sleep support” claims

GoHealthy Calm and Sleep Support Magnesium Plus ($22.99)

GoHealthy Calm and Sleep Support Magnesium Plus.
GoHealthy Calm and Sleep Support Magnesium Plus.


“Supports a good night sleep by promoting calm, relaxation and helping to switch off a busy mind.”

“Soothes muscle tension, helps support kids during growth spurts and boosts immunity.”

Main ingredients

Magnesium, chamomile, vitamin D3, tart cherry, vitamin C and zinc.

Radiance Kids Gummies Calm and Focus ($16.90)

Radiance Kids Gummies Calm and Focus.
Radiance Kids Gummies Calm and Focus.


“Combined magnesium with the amino acid L-theanine to support calm and settled behaviour in children when they may struggle to relax or focus.”

“L-theanine supports the production of calming brain chemicals and works to promote relaxation without sedation.”

Main ingredients

Magnesium and L-theanine.


Magnesium, the main ingredient in GoHealthy and Radiance “calm” supplements, is essential for good health, regulating muscle and nerve function, blood sugar levels and blood pressure, and helping to make protein, bone and DNA.

While GoHealthy claims its Calm and Sleep Support Magnesium Plus will “support a good night sleep”, there’s little evidence magnesium helps sleep. Studies to test its effectiveness haven’t been large enough to produce meaningful results.

There have been some trials in adults to measure magnesium’s benefit in managing stress and mild anxiety but the results were inconclusive. A 2017 evaluation of the studies published in the journal Nutrients found that while magnesium may hold promise, most of the trials were badly designed and lacked placebo controls.

“There really needs to be more evidence before we can state that magnesium can help with anxiety,” University of Otago Department of Human Nutrition senior lecturer Katherine Black said.

A diet containing foods such as bananas, avocado, nuts (almonds and cashews), milk, peas and beans will ensure most of us get the magnesium we need.


The GoHealthy supplement also includes chamomile. While it’s been used in traditional medicine, clinical evidence of its effectiveness is lacking.

A 2009 study published in the Journal of Clinical Psychopharmacology showed chamomile extract may have modest benefits for generalised anxiety disorder in adults but researchers pointed out other chamomile preparations (for example, tea or oil) may produce different results. Good evidence for the herb’s claimed properties is yet to emerge.


The Radiance gummies also contain L-theanine. The amino acid is found in tea leaves (you’ll get about the same amount in a cup of black tea as in one of these supplements).

PharmaCare, which owns the Radiance brand, said it was “confident that our products support the label information we provide”.

There’s some evidence L-theanine helps adults with stress and anxiety, and aids sleep for children and adolescents with ADHD. However, no study went for longer than eight weeks and some of the doses were eight times more than what’s in the Radiance supplement. More studies are needed to assess its safety and whether it’s effective.

Our advice

Rather than forking out for unproven supplements, there are simple steps you can take if you’re worried your child isn’t sleeping or spending too much time glued to a screen:

  • Have a regular bedtime routine.

  • Keep them active during the day to help them sleep at night.

  • Avoid serving big meals or drinks within one to two hours of bedtime, though a snack may help some kids.

  • Make sure kids put their devices away for at least an hour before bed and don’t allow TVs or other screens in the bedroom.

  • You can reduce the brightness of devices by installing blue light filters, available at app stores. If they’re using a PC, activate the night light setting. These will display warmer colours that are easier on the eye.

  • Cap recreational screen time at two hours for kids aged over five, or one hour for pre-schoolers.

If your child is struggling to sleep due to stress or anxiety, see your family doctor (see “How to find a therapist”).

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