The painful bone disorder rickets appears to be making a resurgence among infants and children in New Zealand, and there are worries cases are going unreported.
The painful bone disorder rickets appears to be making a resurgence among infants and children in New Zealand, and there are worries cases are going unreported.
Rickets is a rare and painful bone-growth disease caused by a lack of calcium, phosphorous or vitamin D.
A paediatrician tracking national rates says it appears to be making a resurgence among very young children in NZ.
He says clinicians need to be aware of the risk, amid concern families aren’t being recommended vitamin D supplements.
Professor Ben Wheeler says rickets should be a quirk of a bygone era: a disease belonging in a Charles Dickens novel more than a New Zealand paediatric clinic in 2025.
Yet the painful bone growth disorder appears to be making a mysterious resurgence among infants and young childrenhere – and Wheeler worries the cases being reported each month are just the “tip of the iceberg”.
Its list of symptoms are harrowing: seizures, cramps, bow-leggedness, deformed teeth or skulls, muscle weakness, slowed growth and an increased risk of spontaneous broken bones.
Wheeler, a University of Otago researcher and Dunedin Hospital paediatric endocrinologist, said the condition sometimes didn’t come to light until a child suddenly began convulsing.
“Most families have never seen that before and it’s an incredibly distressing thing.”
A diagnosis often came with days of hospitalisation with intravenous therapy and investigation, he said, which added to the trauma.
Rickets is often caused by a lack of calcium, phosphorous or vitamin D, which usually comes from UVB rays from the sun, as well as oily fish, eggs or dairy products.
When a survey between 2011 and 2013 recorded 60 cases, the Ministry of Health was prompted to recommend daily vitamin D supplements for all breastfed babies in their first year.
A new survey, which Otago’s New Zealand Paediatric Surveillance Unit has been running since September, has already turned up 20 cases.
“It appears the problem may be getting worse rather than better: if this pattern continues, we might end up with 180 cases over three years, rather than 60.”
Even more concerning was that none of the cases Wheeler’s team saw had been prescribed the recommended vitamin D supplements.
Otago University researcher and Dunedin Hospital pediatrician Professor Ben Wheeler.
In some instances, families had asked but not been given them.
“Ensuring just one little drop into a baby’s mouth every day, that costs almost nothing, and this whole issue would be gone,” Wheeler said.
“This is also likely just the tip of the iceberg: we’re seeing those children who are unwell enough to end up in hospital, but there’ll be a huge number that never come to our attention and slowly heal up as they get older.”
The cases appeared to be evenly distributed across the country, with a slight clustering in the Auckland and Waikato regions.
That could be down to a higher population in those areas of people with darker skin pigments – a key risk factor along with being exclusively breastfed and under the age of 3.
Researchers have earlier raised concerns about Kiwi kids not getting enough vitamin D, with one study finding around a third of primary school children tested across Auckland didn’t meet recommended levels.
For babies at that critical risk stage, Wheeler said more effort was urgently needed to ensure they received supplements.
“We’ve got the mechanisms in place to eradicate it, if vitamin D was offered to every family,” he said.
“This should be an illness that’s really relegated to the history books – just think the Industrial Revolution, when there was terrible smog and nutrition – because now, we know how to prevent this problem.”
The Herald approached the Ministry of Health and Health New Zealand over whether it was concerned at the trend in cases – and what actions it was taking to prevent them.
A ministry spokesperson said there may be several factors contributing to increasing numbers, including maternal and child nutrition, or higher awareness resulting in increased diagnosis.
“Health New Zealand has up to date guidance in place to ensure that health professionals provide advice and support to parents to ensure their babies are getting enough vitamin D.”
But Royal NZ College of General Practitioners medical director Dr Luke Bradford, whose Tauranga practice diagnosed a rickets case last year, argued there was a need for clearer recommendations for clinicians.
“Rickets tends to get on your radar once you’ve picked a case up, and then you’re suddenly hyper-vigilant of it: but surveys like this one will definitely help increase our awareness.”
Wheeler said: “We’d love health workers, from maternity care through to early life care, to be more aware of how important these supplements are for bone health.
“And we’d hope that the numbers we’ve seen over these last few months are just an aberration.”
Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.
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