Beta carotene is the
plant source of
Vitamin A. It is the
yellow-
orange pigment that colors
carrots, apricots, peaches, melons, mangoes, and pumpkins. It is also present in dark
green vegetables but the yellow is masked by the green
chlorophyll. If you eat enough carrots your
skin can turn yellow. Breastmilk can also turn yellow from high levels of beta carotene in a mother's diet. Our body splits the beta carotene molecule into two molecules of Vitamin A.
Vitamin A (another type -
retinol) can also be had from
meat, especially
liver. A well nourished adult can get by without new sources of Vitamin A for about 2 years (because of liver stores). However, most of the world gets their Vitamin A as beta carotene from
plant sources. Vitamin A
deficiency can cause
blindness or in less severe cases bad
night vision. This is the "eat your carrots, they are good for your eyes" basis. In much of our world where meat and fruit or vegetables are not available, large populations just doesn't get enough Vitamin A. The resulting deficiency is responsible for "at least a million children who die every year because they are weakened by vitamin-A deficiency and an additional 350,000 who go
blind."
Rice is a stable amoung many of the poor and malnourished people of the developing world (for those who have food at all). But rice alone didn't provide enough Vitamin A. Recently
genetic engineering has created a "
golden rice" by blending the
gene's of common rice with
DNA from
bacteria and
daffodils yielding a rice with built in beta carotene.
reference: Friday, March 16, 2001
Grains Of Hope
BY J. MADELEINE NASH/ZURICH
www.time.com
Thanks to enkidu for pointing out and noding on carotenemia, which is the name of the benign phenomenon of skin turning yellow (but not the whites of the eyes) when excess beta-carotene is ingested (happens a lot with little kids).