Information on Vitamin D Synthesis / Erythemal UV

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Exposure Time for Vitamin D Synthesis / MED (Climatology):Sapporo

Exposure Time around Noon (min.)
January February March
early middle late early middle late early middle late
MED 300 300 250 150 200 150 100 70 70
600 cm2 200 200 150 80 90 55 50 30 25
1200 cm2 100 100 70 40 45 30 25 15 15

April May June
early middle late early middle late early middle late
MED 70 60 50 45 45 40 40 40 35
600 cm2 25 25 20 15 15 15 15 15 10
1200 cm2 15 10 10 8 8 7 8 7 6

July August September
early middle late early middle late early middle late
MED 30 35 30 25 30 40 40 60 55
600 cm2 10 10 10 9 10 15 15 20 20
1200 cm2 5 6 6 4 5 6 7 10 10

October November December
early middle late early middle late early middle late
MED 70 90 100 200 200 250 300 350 400
600 cm2 25 40 50 100 100 150 200 250 250
1200 cm2 15 20 25 60 60 70 100 100 150

The numerical values in the row of 'MED', '600 cm2' and '1200 cm2' show the mean time to reach MED (Minimal Erythema Dose), the time required for 10 µg Vitamin D to be produced for a skin area of 600 cm2, and 1200 cm2 exposed to solar radiation in minutes, respectively.
By clicking each 10 day period, you can also see a diurnal variation of exposure time for that period.

Appropriate exposure time at every site shown below can be seen.
Cape Ochi-ishi (Hokkaido), Rikubetsu (Hokkaido), Sapporo (Hokkaido), Aomori (Aomori), Tsukuba (Ibaraki), Yokohama (Kanagawa), Nagoya (Aichi), Otsu (Shiga), Osaka (Osaka), Miyazaki (Miyazaki), Cape Hedo (Okinawa), Hateruma (Okinawa).

Position of Sapporo