Vitamin D in 7: Rickets in industrial cities

Readers get the synthesis pathway, latitude patterns, and myths that turn hormones into racial folklore. Nothing on this page ranks intelligence, worth or civilization by group. No. Traits can vary by place without slicing humanity into ranked subspecies. Because curiosity about bodies is valid — and unanswered curiosity is where race myths recruit.

Only to explain mechanisms or public health. Averages never become league tables of worth. No. Clinical decisions need clinicians, not atlas pages. By preferring review-level consensus and labeling open debates. A gradual change in trait frequency across geography, rather than a sharp racial border.

Yes — dairying, malaria and altitude are classic feedback loops. See related diversity topics and the atlas page on genetic-distance myths. Vitamin D begins as a skin precursor converted by UVB light, then activated in liver and kidney to a hormone regulating calcium and immune signaling.