Information on Vitamin D Synthesis / Erythemal UV

Japanese

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

Exposure Time around Noon (min.)
January February March
early middle late early middle late early middle late
MED 70 70 60 70 50 45 50 40 30
600 cm2 30 30 25 30 20 15 20 15 10
1200 cm2 15 15 15 15 9 8 10 7 6

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

July August September
early middle late early middle late early middle late
MED 20 20 20 25 20 25 25 25 30
600 cm2 7 7 7 8 7 8 9 8 9
1200 cm2 4 3 3 4 4 4 5 4 5

October November December
early middle late early middle late early middle late
MED 30 35 35 50 50 60 80 80 65
600 cm2 10 15 15 20 15 25 30 30 25
1200 cm2 5 6 6 9 9 10 15 15 15

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 Hedo