New insights from the Canadian Paediatric Society highlight the uneven risk of vitamin D deficiency in Canada, with infants in northern, darker-skinned, and Indigenous communities facing heightened vulnerability and seasonal challenges complicating prevention strategies.
Vitamin D deficiency in Canada is not a uniform problem. According to the Canadian Paediatric Society, the greatest risk is concentrated among breastfed infants, Indigenous communities, people living north of the 55th parallel, people with darker skin pigmentation and those with limited sun exposure. The result is a guidance picture that changes by age, geography and season rather than one simple national rule.
Latitude matters because winter sunlight in much of northern Canada is too weak to help the body make enough vitamin D, even for people who spend time outdoors. The Canadian Paediatric Society says infants in areas north of 55 degrees latitude should receive 800 IU daily from October to April, double the 400 IU recommended elsewhere during the year. Health Canada similarly advises 400 IU a day for exclusively and partially breastfed infants through the first year of life.
Skin tone also affects risk, because melanin reduces the skin’s ability to produce vitamin D from UVB light. The CDC notes that darker skin, high latitude and limited sun exposure can raise the chance of deficiency in infants, while the Canadian Paediatric Society has long warned that Indigenous infants, particularly those in northern communities, face a disproportionate burden. For parents and caregivers, that means general advice to “get more sun” is often not enough.
Infants and pregnant or breastfeeding women are given separate guidance because breast milk alone does not reliably provide enough vitamin D. The Canadian Paediatric Society recommends that pregnant or breastfeeding women discuss a supplement of 2,000 IU a day with a doctor, especially in winter. The Canadian Dermatology Association also recommends meeting needs through food and oral supplements rather than increasing sun exposure, pointing to the skin cancer risk.
The target level itself has also become more ambitious. The Canadian Paediatric Society now refers to a desirable blood range of 75 to 225 nmol/L, which is higher than older standards and means some people previously considered adequate may now fall short. That is why experts stress that population advice can only go so far: a blood test remains the best way to know whether an individual child or parent actually needs more vitamin D.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
