What year did they start adding vitamin D to milk?

America (and the UK) in the early 1900's was seeing a rising epidemic of rickets, a vitamin D deficiency in children characterized by a softening of the bones. These softened bones would lose structural integrity and result in a "greenstick" fracture (like trying to break a green stick, one side would shred while the inside would bend.) They introduced Vitamin D to milk in the early 1920's, and as a result became a rare condition.
Vitamin D has been increasingly in the news (since around 2007) as a wonder vitamin, having many health benefits including the increased absorption of calcium. while this spurs vitamin sales, it is a fallacy that it helps the absorption of calcium. they DO coexist in the bones, however, if you were deficient in vitamin D, you'd see a softening of the bones, not a lack of calcium. Rickets in adults is known as Osteomalacia. I contest that if the population was in fact deficient in vitamin D, our ever-alert media would have alerted us to the rising epidemic of osteomalacia and rickets. There is no epidemic, proving that the current vitamin D deficiency is all about marketing, and not about health.