Information on Vitamin D Synthesis / Erythemal UV

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

Exposure Time around Noon (min.)
January February March
early middle late early middle late early middle late
MED 150 100 100 100 80 70 60 60 35
600 cm2 60 50 50 40 30 30 25 25 10
1200 cm2 30 25 25 20 15 15 10 10 6

April May June
early middle late early middle late early middle late
MED 40 40 35 40 30 30 25 30 40
600 cm2 15 15 10 15 9 10 9 10 15
1200 cm2 8 7 6 6 5 5 4 5 7

July August September
early middle late early middle late early middle late
MED 30 30 30 30 25 30 25 45 40
600 cm2 10 10 9 9 9 10 8 15 15
1200 cm2 5 5 5 5 4 5 4 8 7

October November December
early middle late early middle late early middle late
MED 30 45 60 50 80 80 90 100 150
600 cm2 10 15 20 20 30 30 40 45 60
1200 cm2 5 8 10 9 15 15 20 25 30

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 Otsu