Air pollution texts often made the note, but I’ve not seen it talked about much recently: Air pollution in the U.S. (and England) was so bad in the first years of the 20th century that it actually shut out the sun, and an epidemic of rickets followed.
Public health officials, clever devils, discovered a form of vitamin D that prevented rickets. It turns out that humans manufacture vitamin D from cholesterol, using ultraviolet B from the sun. So, when the sun was smokily eclipsed, rickets proliferated.
In an era when technical and legal tools were inadequate to clean up the air pollution, physicians, nutritionists and researchers struck on the idea of supplementing food with vitamin D — and that is how we come to have vitamin D-fortified milk today, and a lot less rickets.
I was happy to find a publication at the National Institutes of Health that relates this history, at least in part, “Solar Ultraviolet Radiation and Vitamin D: A Historical Perspective,” by Kumaravel Rajakumar, MD, Susan L. Greenspan, MD, Stephen B. Thomas, PhD, and Michael F. Holick, MD, PhD, in American Journal of Public Health, October 2007, Vol 97, No. 10.
At the dawn of the 20th century, the expansive industrialization and urban migration in the major cities of western Europe and the northern United States set the stage for the high prevalence of rickets among infants residing in those polluted and “sunless” cities. Overcrowded living conditions in the big-city slums and tenements and the sunlight deprivation precipitated by atmospheric pollution from smoke and smog were responsible for a rickets epidemic. Increased ozone concentration from industrial pollution and the haze and clouds from atmospheric pollution compromise vitamin D production by absorbing the UV-B photons essential for its synthesis.
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Edwards Park states, “But for rickets vitamin D would not have been discovered. Its discovery was the secret to rickets; its use is essentially the therapy of that disease.” The discovery of vitamin D led to the eradication of the epidemic rickets of the early 20th century. Pioneering advances were made in the understanding of vitamin D and rickets from 1915 to 1935. The discovery of the synthesis of vitamin D by the irradiation of foods was the “jewel in the crown” of vitamin D discoveries. This discovery was a catalyst for the public health triumph against rickets. It became feasible to fortify and enrich milk and other foods with vitamin D to ensure that the general population was likely to consume sufficient vitamin D.
It’s a good article with detailed history of rickets, the search to find what turned out to be vitamin D, and the use of nutritional supplements to eradicate a nasty, crippling disease in children. Happy to see it online.
Some of our greatest triumphs in science, technology and public health are too little known. I am working on the history of technology and science, and particularly its wedding with social progressivism in the Progressive Age, part of a project I was fortunate to stumble into in the Dallas Independent School District funded by a Teaching American History Grant from the U.S. Department of Education. Sadly, Republicans in Congress insisted on cutting those grants to improve teaching with greater emphasis on original sources and original documents.
More Americans, more American school kids, should know about the triumphs of public health and science. Maybe highlighting some of those advances here can help another teacher somewhere else.