Rickets eradication

The precursors of vitamins D2 and D3 are ergosterol and 7-dehydrocholesterol, respectively. These precursors or provitamins can be converted into the respective D vitamins by irradiation with ultraviolet light. In addition to the two major provitamins, there are several other sterols that can acquire vitamin D activity when irradiated. The provitamins can be converted to vitamin D in the human skin by exposure to sunlight. Because very few foods are good sources of vitamin D, humans have a greater likelihood of vitamin D deficiency than of any other vitamin deficiency. Enrichment of some foods with vitamin D has significantly helped to eradicate rickets, which is a vitamin D deficiency disease. Margarine and milk are the foods commonly used as carrier for added vitamin D. 

Rickets was more or less eradicated as a nutritional deficiency disease dur-ingthe 1950s, as aresultofwidespread enrichment ofinfantfoods with vitamin D. The level of supplementation was reduced as a result of the development of hypercalcemia caused by vitamin D intoxication (Section 3.6.1) in a small number of especially susceptible infants. As a result, rickets has reemerged, especially in northern cities in temperate countries. 

Rickets was more or less eradicated as a nutritional deficiency disease during the 1950s, as a result of widespread enrichment of infant foods with vitamin... 

The addition of vitamin D to fluid whole milk thereby resulting in a widely used food providing calcium, phosphorus, and vitamin D—has been credited with the virtual eradication of rickets among children in the United States. The vitamin D fortification of milk to provide a concentration of 400 lU per quart has been endorsed by the Food and Nutrition Board, National Research Council-National Academy of Sciences the American Academy of Pediatrics and the American Medical Association. 

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