Provitamin Carotenoids

Some articles on carotenoids, provitamin, carotenoid:

beta-Carotene - Provitamin A Activity
... Plant carotenoids are the primary dietary source of provitamin A worldwide, with β-carotene as the most well-known provitamin A carotenoid ... Carotenoid absorption is restricted to the duodenum of the small intestine and dependent on Class B scavenger receptor (SR-B1) membrane protein, which are also responsible ... The absorption and conversion of carotenoids may depend on the form that the β-carotene is in (e.g ...
TROL - Equivalencies of Retinoids and Carotenoids (IU)
... As some carotenoids can be converted into vitamin A, attempts have been made to determine how much of them in the diet is equivalent to a particular amount of retinol, so that comparisons can be made of the benefit of ... unit (IU) was equal to 0.3 μg of retinol, 0.6 μg of β-carotene, or 1.2 μg of other provitamin-A carotenoids was used ... Newer research has shown that the absorption of provitamin-A carotenoids is only half as much as previously thought ...