The 11 others varied from three times the recommended amount to none at all. Vitamin D helps bones absorb calcium which is essential for the development of healthy bones and teeth. Without calcium the body is at a greater risk of developing bone weakening diseases including osteoporosis. Sunlight is the best natural source of Vitamin D but in the northern United States and Canada, especially during the winter, milk fortified with Vitamin D becomes the chief source of Vitamin D for many people. Decades ago, dairy processors began to add Vitamin D to milk, in an effort to help prevent rickets, a bone disease in children.
Milk cartons promise a specific level of Vitamin D inside.
If the numbers are accurate, a little over two glasses of milk a day should provide all the Vitamin D you need. But, last year, researchers in Boston found the information on American milk cartons was rarely reliable, and that milk samples seldom contained the amount of Vitamin D the labels claimed. We conducted our own survey and collected 15 containers of milk from five different British Columbia milk companies. We shipped them off to the Boston University Medical Center where researchers tested our samples. What they found was significant enough to be published in the New England Journal of Medicine .