Vitamin D in Canada
Canada's large latitude range produces substantial differences in seasonal sunlight. Latitude changes potential skin production; it does not prove that an individual is deficient or create a city-specific supplement dose. Health Canada guidance combines food, fortification, and age-based recommendations.
Health Canada RDAs
- Ages 1–70: 600 IU/day (15 µg).
- Age 70+: 800 IU/day (20 µg).
- Pregnancy / lactation: 600 IU/day.
- Health Canada supplementation recommendation for adults over 50: 400 IU/day cholecalciferol year-round in addition to dietary sources.
- Tolerable upper limit: 4,000 IU/day for adults.
Milk fortification
Canadian regulations require vitamin D fortification of all fluid milk and margarine at defined levels (35–45 IU per 100 mL milk; 5.3 µg per 100 g margarine). This has substantially reduced rickets since the 1970s but hasn't eliminated adult winter deficiency, given the modest doses involved.
Deficiency cannot be inferred from a postal code
Canadian surveys use defined populations, collection periods, and blood-level thresholds. Those results should not be copied into a city guide as a local prevalence estimate. Diet, skin pigmentation, clothing, time outdoors, age, health conditions, and season all affect risk.
When Canadians make vitamin D
Solar UVB changes continuously by latitude, season, time of day, elevation, ozone, cloud, and surface reflection. Explore the transparent monthly examples for Canadian pilot cities, then customize skin, clothing, cloud, and outdoor time in the calculator.
Use Canadian guidance
Product availability is not a dosing recommendation. Health Canada advises adults age 51 and older to take a daily 400 IU (10 µg) supplement in addition to food sources. People with diagnosed deficiency or medical conditions need individualized advice rather than a latitude-based dose.
Testing 25(OH)D in Canada
Provincial coverage and clinical indications vary. Check your province's current policy or ask a clinician; this page does not recommend routine testing for every healthy person.