National Milk Day 2020 is celebrated in the United States of America every year on January 11. The fun day is observed to recall the particular day when the first milk deliveries in glass bottles began in the States in the year 1878. The presence of calcium in the milk is high in quantity compared to other food items. Therefore, milk helps in the development of strong bones and teeth. Apart from all the health benefits, there are some interesting facts about milk that you must totally know about.