Life / Health

Rickets still striking Canadian kids

Vitamin D deficiency is at the root of rickets, a childhood bone disease that mostly affects babies under the age of two.

A young boy’s wrist deformity indicates rickets, which is caused by severe vitamin D deficiency in small children and inadequate vitamin D intake in breastfeeding mothers.

Dr. Daniel Flanders / Twitter

A young boy’s wrist deformity indicates rickets, which is caused by severe vitamin D deficiency in small children and inadequate vitamin D intake in breastfeeding mothers.

Last week, Toronto pediatrician Dr. Daniel Flanders tweeted a photo of a toddler with an enlarged wrist poking out of a Thomas the Tank Engine sweatshirt, with this medical riddle:

“Case from last year: 1 year old, extremely picky eater, wrist looks like this. Diagnosis?”

The answer: rickets, a childhood bone disease that mostly strikes babies under the age of two. It belongs in ye olde medical books, alongside smallpox and scurvy.

And it really should stay there. Because rickets is caused by severe vitamin D deficiency, it’s preventable — yet it persists, said Stephanie Atkinson, a professor of pediatrics at McMaster University who researches neonatal nutrition.

National data is scant, but a one-time survey of about a quarter of Canadian pediatricians in 2015 turned up 149 cases of children with severe vitamin D deficiency in a year, including 48 rickets cases — and two deaths.

Vitamin D helps “mineralize” growing bones with calcium. Without it, they’re soft and weak, and the result can be rickets — fractures, stunted growth, thickened wrists and ankles, bow legs and knock knees, plus a host of other health problems, including developmental delay, frequent infections, seizures and even death.

Why are there still cases of rickets in 2017? Babies get vitamin D one of three ways, Atkinson explained: from stores they build up while still in the womb, from the sun and from their diet.

For the most part, and with good reason, we don’t put babies out in the sun anymore. Prenatal vitamins give babies the gift of good vitamin D stores at birth, but not everyone takes them. Baby formula and cow’s milk are fortified with vitamin D, but only a little bit of the vitamin D a mother consumes is passed into breast milk, Atkinson said, so exclusive breastfeeding without supplementing is a major cause of rickets.

Living in the North — with its poor access to both the sun and nutritious food — is another risk factor, as is darker skin colour in both mother and baby, because melanin reduces the absorption of sunlight that helps the body make vitamin D.

Modern nutrition trends could play a role, too. A rickets case was reported in the U.S. this year in an 11-week-old breastfed baby whose mother had cut dairy from her diet over concerns about colic.

Celia Rodd, a pediatric endocrinologist who researches this issue at the Children’s Hospital Research Institute of Manitoba, said, “Health-care providers may not know that some plant-based beverages (hemp, almond etc.) are not fortified with Vitamin D or calcium.”

“The only rationale I’ve heard,” Atkinson said, referring to health trends, “is that some people who are really committed to breastfeeding feel that their milk is the perfect food, and no supplement is needed. Then there’s the concern about anything foreign being given to the baby. (Some) mothers might be averse to any kind of supplement.”

Along similar lines, cases of life-threatening bleeding have been reported in infants in the U.S. because their parents refused the shot of vitamin K routinely given to newborns.

But for the most part, the problem is a lack of knowledge and compliance with recommendations, Atkinson said.

She pointed to a 2010 Quebec study that found one-quarter of parents with exclusively breastfed babies were not following the recommendation to supplement with vitamin D.

“Unfortunately, although we know a lot about the risk factors, but we haven’t been able to communicate that widely enough.”

How much vitamin D is enough?

Because breast milk alone may not provide enough vitamin D, and exposing babies to sun is not advised, the Canadian Pediatric Society recommends all babies receive supplements.

All babies under 12 months old need 400 IU (international units) of vitamin D per day, while babies at increased risk, such as those in northern latitudes, need 800 IU.

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