Rickets is preventable, but kids keep getting it
Severe vitamin D deficiency is behind the childhood disease and causes soft, weak bones
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:1year old, extremely picky eater, wrist looks like this. Diagnosis?”
The answer: rickets, a childhood bone disease that mostly strikes babies under the age of 2. 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 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 and a host of other health problems, including developmental delay, 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.
But for the most part, the problem is a lack of knowledge and compliance with recommendations, Atkinson said.
“Unfortunately, although we know a lot about the risk factors, we haven’t been able to communicate that widely enough.”