A shallow angle from the sun give you that long shadow, but it also gives the light lots of extra air to pass through sideways on it’s way down out of space. The extra air filters out more light, and without an intense enough light your skin won’t make Vitamin D.
The First Law trilogy by Joe Abercrombie is a fine example of grimdark high fantasy. It isn’t overflowing with sex scenes, but carnal relationships are definitely in play.