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

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

Exposure Time around Noon (min.)

	January			February			March
	early	middle	late	early	middle	late	early	middle	late
MED	90	100	80	70	60	55	55	45	50
600 cm²	40	40	30	25	25	20	20	15	15
1200 cm²	20	20	15	14	12	10	10	8	8

	April			May			June
	early	middle	late	early	middle	late	early	middle	late
MED	40	35	30	30	35	30	30	30	30
600 cm²	15	12	10	10	12	10	10	10	10
1200 cm²	7	6	5	5	6	5	5	5	5

	July			August			September
	early	middle	late	early	middle	late	early	middle	late
MED	30	25	25	25	25	25	35	45	45
600 cm²	10	9	9	8	9	8	12	15	15
1200 cm²	5	5	5	4	4	4	6	8	8

	October			November			December
	early	middle	late	early	middle	late	early	middle	late
MED	50	60	60	60	80	90	100	100	100
600 cm²	20	20	20	25	30	35	45	45	45
1200 cm²	9	10	10	12	15	18	22	22	22

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):Yokohama

Position of Yokohama