Milk: Delivering Your Daily Vitamin D
In the early 20th century, rickets (soft bones and skeletal malformation from incomplete bone growth) was common among underprivileged children living in industrialized, northern U.S. cities. Inadequate diet, poor hygiene, and lack of exercise were among the factors believed to play a role in the formation of this disease. The relationship between diet and rickets was not clearly understood until an English physician conducted the first experimental study on rickets with dogs. His observations of specific “anti-rachitic” factors found in cod liver oil, butter and whole milk eventually led to the identification, purification, and synthesis of vitamin D (Rajakumar, 2003). Prior to this discovery, irradiated milk, cod liver oil, and milk from cattle fed irradiated yeast were common treatments to combat rickets (Bishai and Nalubola, 2002). After the discovery of synthetic vitamin D, these products were no longer needed to be used.