There is a long history [0] of populations living in cold places, (Vikings, Eskimos) with less sun using cod liver oil (Levertran) as a "strength tonic", due to

There is a long history [0] of populations living in cold places, (Vikings, Eskimos) with less sun using cod liver oil (Levertran) as a "strength tonic", due to the Vitamin D3 in it. The connection is also pretty well established in regards to lack of sunlight and higher risk for developing rickets [1]. Also found a pretty good NPR piece [2] about this whole issue. [0] http://evclo.com/history/ http://evclo.com/history/ [1] http://pediatrics.aappublications.org/content/112/2/e132 http://pediatrics.aappublications.org/content/112/2/e132 [2] https://www.npr.org/sections/13.7/2012/06/21/155297960/for-summers-first-full-day-the-science-of-skin-color-and-vitamin-d https://www.npr.org/sections/13.7/2012/06/21/155297960/for-s...