Biological Pathways Explorer
Follow the step-by-step processes that connect light exposure to biological effects. From UV-triggered vitamin D synthesis to the cellular mechanisms of red light therapy.
Vitamin D Synthesis Pathway
Click on any node to learn about each step
• UV-B light (290-315nm) initiates the process by converting 7-dehydrocholesterol to previtamin D3.
• Body heat converts previtamin D3 to vitamin D3 over several hours.
• The liver and kidneys perform two hydroxylation steps to create the active hormone form.
• Active vitamin D affects thousands of genes throughout the body.
Understanding Pathways
UV → Vitamin D
UV-B light triggers a photochemical reaction in skin that begins the multi-step process of vitamin D synthesis, requiring liver and kidney processing.
Red Light → ATP
Red and NIR light enhances mitochondrial function by improving electron transport efficiency, resulting in increased cellular energy production.
DHA → Tan Color
Spray tan works through the Maillard reaction—the same chemistry that browns food—creating pigments in the outermost layer of dead skin cells.