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Increased Vitamin D Consumption Encouraged by the AAD
Posted: December 10, 2008
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The review is being sponsored by the U.S. National Institutes of Health (NIH) and Health Canada, with a final report estimated to be complete in spring 2010.
Just last month, the American Academy of Pediatrics (AAP) issued a report stating that children should be consuming double the usually recommended levels of vitamin D—400 International Units (IUs) of the vitamin per day, compared to the 200 IUs previously recommended by AAP. And in recent weeks, a group of 18 scientists from the University of California said recommended daily intakes of vitamin D should be raised to 2,000 International Units for vitamin D3.
Vitamin D refers to two biologically inactive precursors—D3, also known as cholecalciferol, and D2, also known as ergocalciferol. The former, produced in the skin on exposure to UVB radiation (290 to 320 nanometers), is said to be more bioactive.
Both D3 and D2 precursors are hydroxylated in the liver and kidneys to form 25- hydroxyvitamin D (25(OH)D), the non-active 'storage' form, and 1,25-dihydroxyvitamin D (1,25(OH)2D), the biologically active form that is tightly controlled by the body.