AVOCADO

1 Kg avocado = 150/200 g salmon = 10 to 15 minutes with arms and face exposed to the summer sun at the latitude of Hamburg (a lot less around the Mediterrean), 

it covers the daily need of vitamin D!

From: Vitamin D: A Vital Hormone,  Dörthe Eickelberg, Pierre Girard, Xenius Arte Tv, Germany 2016