Vitamin D in Montréal
Montréal’s latitude produces a large summer-to-winter swing in modeled UVB availability. Location affects possible vitamin D production from sunlight; it does not change the age-based dietary reference intake or determine whether a particular person needs a supplement.
See Montréal's sunlight estimate in the calculatorWhat the monthly model shows
The chart uses latitude 45.5019°, longitude -73.5674°, and elevation 36 m. It is model version 2026.09 with reference year 2026. It is not a weather forecast or measured local UV record.
| Month | Modeled sunlight | Gap to RDA* |
|---|---|---|
| January | 11 IU/day | 389 IU/day |
| February | 78 IU/day | 322 IU/day |
| March | 336 IU/day | 64 IU/day |
| April | 971 IU/day | 0 IU/day |
| May | 1,757 IU/day | 0 IU/day |
| June | 2,535 IU/day | 0 IU/day |
| July | 2,742 IU/day | 0 IU/day |
| August | 2,160 IU/day | 0 IU/day |
| September | 1,153 IU/day | 0 IU/day |
| October | 309 IU/day | 91 IU/day |
| November | 37 IU/day | 363 IU/day |
| December | 6 IU/day | 394 IU/day |
*Mathematical gap after modeled sunlight and an assumed 200 IU/day from food. This is not a supplement recommendation.
How much vitamin D do adults need?
Health Canada recommends 600 IU (15 µg) daily from all sources for ages 1–70 and 800 IU (20 µg) after age 70. Its food guide advises adults 51 and older to take a daily 400 IU supplement.
Vitamin D and seasonal depression
Seasonal affective disorder is a form of depression related to seasonal changes in daylight. Low vitamin D can coexist with it, but research on vitamin D as a SAD treatment is mixed. Established options include clinician-guided light therapy, psychotherapy, and medication. Read the evidence guide to vitamin D and SAD.