How Much Sunshine Do We Really Need? Experts Weigh Sun Exposure and Vitamin D

Beneath the simple question of how much sun we need lies a more complex truth: the human body's relationship with light is as varied as the people who inhabit it. Vitamin D, that quiet nutrient manufactured at the intersection of skin and sky, resists the comfort of universal prescriptions — shaped instead by geography, ancestry, age, and the invisible architecture of individual biology. Health experts are now urging that what we once treated as common knowledge be replaced with something rarer and more valuable: personalized understanding.