The history of vitamin D
The discovery of vitamin D came long after the discovery of rickets. By researching the disease for hundreds of years, scientists finally discovered that its preventative treatment was none other than vitamin D. The following describes some vitamin D history.
Early Research in Children’s Bone Disease
Mid-1600s: The term ‘rickets’ had not been coined yet, but two scientists named Whistler and Glisson had independently researched and published a scientific paper describing the disease. Neither of these reports touched on preventative methods, such as diet or sun exposure.
1824: D. Scheutte was the first person to prescribe cod-liver oil as a treatment for rickets. Cod-liver oil is fish oil that contains vitamins A and D.
Sunlight and Air Pollution
1840: Sniadecki, a Polish doctor, reported that children living in an environment with less sunlight (in the polluted centre of Warsaw) were more likely to suffer from rickets than children living in an environment with more sunlight (in the countryside, outside of Warsaw). Alas, he was not taken seriously by his peers. Scientists back then did not believe that the sun’s rays could impact the human skeleton. End of nineteenth century: More than 90 per cent of European children living in polluted urban environments were estimated to suffer from rickets.
1880s: Theobald Palm of England noted that rickets seemed to be caused by a lack of sunlight.
1900: Boston and New York City were booming. Along with this economic success, there was an increase in cases of rickets found in children who lived in these industrialized cities. It is reported that during this period, more than 80 per cent of children in Boston suffered from rickets. 
Early Vitamin Research
1905: William Fletcher of England realized that by removing certain factors (vitamins) from food, diseases occurred.
1906: Hopkins proposed that ‘essential dietary factors’ were required to prevent diseases such as rickets or scurvy.
1912: Cashmir Funk of Poland coined the special components of food as “vitamine” (“vita” = life and “amine” = the compounds found in thiamine from his rice husks which were part of his research).
1918: Sir Edward Mellanby discovered two important facts; 1) indoor beagles fed oatmeal developed rickets and 2) by adding cod liver oil to their oatmeal, the beagles seemed to be treated of their rickets. 
1921: Palm’s proposal about the lack of sunlight as the cause of rickets was confirmed by Elmer McCollum and Marguerite Davis (both Americans). They demonstrated that by giving rats cod liver oil and exposing them to ultraviolet light, they increased the rats’ bone growth.
1922: McCollum coined the fat-soluble ‘accessory food factor’ (which we now call vitamins) that was by now known to prevent rickets as vitamin D. Vitamins A, B and C had just recently been discovered and named, thus it seemed logical to continue the alphabetical trend. [1,3] Focus on vitamin D
1920s: Harry Steenbock of Wisconsin, U.S.A., patented a method of irradiating foods to enrich them with vitamin D.
1920s and 1930s: The chemical structures of the different types of vitamin D were discovered by Windaus and his colleagues in Germany.
1928: Adolf Windaus received the Nobel Peace Prize “for services rendered through his research into the constitution of the sterols and their connection with the vitamins”. 
1936: Vitamin D3 was established as being produced in the skin as a result to exposure to ultraviolet (UV) rays. 
1936: Vitamin D3 was recognized by Windaus as the specific factor in cod liver oil that was responsible for preventing rickets.
1930s: Several food items in the United States were fortified with vitamin D. [1,3]
Mid-1940s: Steenbock’s food irradiation invention from the 1920s was largely responsible for eradicating rickets in the United States.
Post Second World War: Sporadic outbreaks of vitamin D intoxication occurred in Britain as a result of an excessive amount of vitamin D added to milk products. 
1955: Velluz listed the multiple chemical steps required to convert ergosterol in fungi to vitamin D2.
1979: Stumpf and his colleagues discovered that vitamin D receptors were found in many parts of the body, including the gastro-intestinal tract, bones and kidneys. 
1982: Holick listed the complete list of chemical steps required to produce vitamin D3 in the skin.
1990s- ongoing: Multiple studies from various countries demonstrate that vitamin D deficiency is increasing. 
History of Vitamin D recommendations:
1963: The American Academy of Pediatrics Committee on Nutrition began to recommend vitamin D supplementation for all infants
2002: Canada recommends vitamin D supplementation for breastfed infants 2006-2008: Ddrops liquid vitamin D supplements were invented in Toronto, Canada in 2006.
In 2007 Ddrops products were commercially available in Canada and soon expanded to other countries. Since then, patents have been awarded worldwide for this unique product and its administration.
2008: The American Academy of Pediatrics recommends that all infants and children, including adolescents, have a minimum daily intake of 400 IU of vitamin D beginning soon after birth
2010: Although many health organizations around the world have already established their own guidelines for vitamin D daily intake, there are often inconsistencies. The Institute of Medicine (IOM), a committee of experts tasked to review vitamin D research, established daily intake recommendations for both vitamin D and calcium for various population groups.
2016: Public Health England states that 10 micrograms or 400 IU of vitamin D are needed daily to help keep healthy bones, teeth and muscles. Vitamin D continues to be a central component in many scientific research protocols.
Originally published on August 15, 2016
 Mary Norval. A Short Circular History of Vitamin D from its Discovery to its Effects. Res Medica, Journal of the Royal Medical Society. Volume 268, Issue 2, 2005.
 George Wolf. The Discovery of Vitamin D: The Contribution of Adolf Windaus. The American Society for Nutritional Sciences. J. Nutr. June 1, 2004, vol. 134 no. 6, 1299-1302. https://jn.nutrition.org/content/134/6/1299.full
 Royal Society of Chemistry. Chemistry in its element: compounds (vitamin D). Podcast transcript (Meera Senthilingam, David Lindsay, Simon Cotton). 2016. http://www.rsc.org/chemistryworld/podcast/CIIEcompounds/transcripts/VitaminD.asp
 Mary Bellis. Vitamins –Production Methods. The History of Vitamins. About.com Inventors. https://inventors.about.com/library/inventors/bl_vitamins.htm
 Frank Greer. Issues in establishing vitamin D recommendations for infants and children The American Journal of Clinical Nutrition, Volume 80, Issue 6, December 2004, Pages 1759S–1762S, https://doi.org/10.1093/ajcn/80.6.1759S
 Canadian Paediatric Society, First Nations and Inuit Health Committee [Principal author: J Godel]. Vitamin D supplementation in northern Native communities. Paediatr Child Health 2002;7:459-63.
 Carol L. Wagner, Frank R. Greer and; and the Section on Breastfeeding and Committee on Nutrition Prevention of Rickets and Vitamin D Deficiency in Infants, Children, and Adolescents Pediatrics November 2008, 122 (5) 1142-1152; DOI: https://doi.org/10.1542/peds.2008-1862
 Institute of Medicine of the National Academies. Dietary Reference Intakes for Calcium and Vitamin D. Report brief November 2010. Revised March 2011. https://www.nationalacademies.org/hmd/~/media/Files/Report%20Files/2010/Dietary-Reference-Intakes-for-Calcium-and-Vitamin-D/Vitamin%20D%20and%20Calcium%202010%20Report%20Brief.pdf