What is the connection between the liver (organ), UV radiation (sunlight), and bone tissue? I need something with more information for an essay

The connection between them is Vitamin D.

Vitamin D can be obtained from food and supplements, or synthesized by our bodies when we receive UV radiation in our skin, which is our major source. However, this vitamin comes inactivated and the only way to activate it is through enzymatic conversion (hydroxylation) in the liver and later in the kidneys.

This vitamin is necessary in the intestines because allows calcium and phosphorus to be observed, leading to normal growth and development of bones and teeth. Without enough vit D, bones become fragile, causing osteoporosis.