Vitamin D: part II; cod liver oil, ultraviolet radiation, and eradication of rickets.

Abstract in brief

• The text explains how understanding of rickets evolved from being a mysterious bone disease to being linked with vitamin D deficiency caused by lack of sunlight exposure or dietary intake, especially in children during the early 20th century.
• Historically, cod liver oil was used as a treatment for rickets since the 1700s, but it was only in the late 1800s and early 1900s that scientists suspected and demonstrated its role due to the presence of vitamin D, along with the discovery of other essential vitamins.
• The recognition that ultraviolet radiation can produce vitamin D in the skin led to advancements like artificial ultraviolet light and food irradiation, which helped in developing new ways to prevent and treat rickets beyond just dietary supplementation.]