The USDA has known this since the early 1980's.
Details at Weston Price March 2012
Apparently Italian pigs are generally "free range" - their bacon having up to 3600 IU of vitamin D per 100 grams
Now farmers just provide pigs with enough vitamin D to prevent their getting rickets
Wonder when pig farmers will get around to supplementing with enough vitamin D to provide benefits in humans
See also VitaminDWiki
- Free range lard has 500 IU vitamin D per teaspoon
- Swine need sunshine or 500-2800 IU vitamin D3
- Free range eggs have 4X as much vitamin D
Summer sausage tastes good. Wonder if it if made from "free range" pigs?