Vitamin D Second Edition

The use of vitamin D has never been approached in the same way that we would expect to see for any modern drug. Unlike other nutrients, we have never had dietary intakes of vitamin D as a reasonable reference point for deciding on how much of this nutrient/drug that people should be consuming. The ambiguity between “nutrient” and “drug” is reasonable when it comes to vitamin D, because there were no meaningful amounts of vitamin D in the kinds of foods that Paleolithic humans would likely have been consuming.