Information on Vitamin D Synthesis / Erythemal UV | Center for Global Environmental Studies

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

Exposure Time around Noon (min.)

	January			February			March
	early	middle	late	early	middle	late	early	middle	late
MED	250	220	200	150	150	100	100	80	70
600 cm²	150	120	100	80	70	45	40	30	25
1200 cm²	80	60	55	40	35	22	20	15	12

	April			May			June
	early	middle	late	early	middle	late	early	middle	late
MED	60	55	50	50	40	40	40	40	35
600 cm²	22	20	15	15	15	15	15	15	12
1200 cm²	12	10	8	8	7	7	7	7	6

	July			August			September
	early	middle	late	early	middle	late	early	middle	late
MED	35	30	30	35	40	40	40	50	55
600 cm²	12	10	10	12	15	15	15	20	20
1200 cm²	6	6	6	6	7	7	7	10	10

	October			November			December
	early	middle	late	early	middle	late	early	middle	late
MED	70	90	100	150	180	200	250	300	300
600 cm²	25	30	50	70	90	120	120	150	150
1200 cm²	15	15	25	35	45	60	70	80	80

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), Sendai (Miyagi), Tsukuba (Ibaraki), Yokohama (Kanagawa), Nagoya (Aichi), Otsu (Shiga), Osaka (Osaka), Miyazaki (Miyazaki), Cape Hedo (Okinawa), Hateruma (Okinawa).

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

Position of Rikubetsu