Information on Vitamin D Synthesis / Erythemal UV

Japanese

Exposure Time for Vitamin D Synthesis / MED (Climatology):Cape Ochi-ishi

Exposure Time around Noon (min.)
January February March
early middle late early middle late early middle late
MED 250 250 200 150 150 100 100 90 80
600 cm2 150 150 100 75 75 45 40 35 30
1200 cm2 70 70 50 40 40 25 20 20 15

April May June
early middle late early middle late early middle late
MED 70 60 50 55 50 50 40 50 45
600 cm2 25 20 15 20 15 20 15 20 15
1200 cm2 15 10 8 10 8 9 8 9 8

July August September
early middle late early middle late early middle late
MED 40 40 40 40 40 40 45 50 55
600 cm2 15 15 15 15 15 15 15 20 20
1200 cm2 7 7 7 7 7 7 8 9 10

October November December
early middle late early middle late early middle late
MED 65 90 100 150 200 200 250 300 250
600 cm2 25 40 45 75 90 100 150 150 150
1200 cm2 15 20 25 40 45 60 75 85 75

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 Cape Ochi-ishi