Part 7/14:
Migration and Adaptation: As populations migrated from sunny regions to northern latitudes, darker skin evolved as protection against UV damage. However, with increased mobility and urban living, many individuals now live in environments with insufficient UVB exposure, especially during winter months.
Changing Lifestyle: The shift from farming communities, where outdoor activity was essential, to indoor work, has decoupled humans from natural sunlight. Fewer people grow their own food or spend time outside for leisure, further reducing natural vitamin D synthesis.