Does the sun give vitamin k?

The sun's UVB rays triggers a modification of a cholesterol-related molecule. This creates a form of vitamin D which is then transported through the circulatory system into the liver where it is transformed into a new form of vitamin D known as 25-hydroxyvitamin D, the derivative that doctors use to assess overall Vitamin D levels.

The sun has no role in the formation of vitamin K as humans cannot synthesize this vitamin. The main sources of vitamin K are dietary sources, or as metabolic by-products of intestinal bacteria.