Answer:
A dietary supplement of cholecalciferol.
Explanation:
Cholecalciferol is made by the skin when it is exposed to the sunlight.It is also known as D₃.Due to not proper exposure to the sunlight the a deficiency of cholecalciferol is generated.Due to which the bones becomes weaker of the people living in cold climates as compared to people living in the warm and sunny climates.