Vitamin D from sunlight in Japan
How long you need in the sun to make vitamin D, and when the sun is too low to make any at all, for 8 cities in Japan.
| City | Latitude | Elevation | Vitamin D winter |
|---|---|---|---|
| Tokyo | 35.69°N | 44 m | 21 Nov – 27 Jan (68 days) |
| Yokohama | 35.43°N | 21 m | 22 Nov – 25 Jan (65 days) |
| Osaka | 34.69°N | 4 m | 26 Nov – 21 Jan (57 days) |
| Nagoya | 35.18°N | 23 m | 23 Nov – 24 Jan (63 days) |
| Sapporo | 43.07°N | 26 m | 22 Oct – 28 Feb (130 days) |
| Fukuoka | 33.60°N | 3 m | 3 Dec – 14 Jan (43 days) |
| Kawasaki | 35.52°N | 1 m | 22 Nov – 26 Jan (66 days) |
| Kobe | 34.69°N | 35 m | 26 Nov – 21 Jan (57 days) |
The same sun that makes vitamin D also burns. UV index and sunburn times in Japan →