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 calculator

What 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.

Modeled daily IU from 30 minutes between 10:00 and 14:00 local solar time, skin type II, long sleeves and pants (15% exposed), 40% cloud cover, grass surface, and SPF 0. Customize every input.

Monthly modeled vitamin D production and gap to adult RDA in Montréal
Month	Modeled sunlight	Gap to RDA*
January	11 IU/day	1,789 IU/day
February	78 IU/day	1,722 IU/day
March	336 IU/day	1,464 IU/day
April	971 IU/day	829 IU/day
May	1,757 IU/day	43 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	647 IU/day
October	309 IU/day	1,491 IU/day
November	37 IU/day	1,763 IU/day
December	6 IU/day	1,794 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.

Read the current Health Canada guidance

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.