送交者: xj 于 2004-12-31, 01:17:23:
回答: 懂胡萝卜的请进。 由 Latino2 于 2004-12-30, 23:06:52:
eating eggs and meat is more helpful. Serious. :-)
provitamin A is abundant in eggs, milks and meat (in the form of retinol), and carotene is also aboundant in vegetables (in particular those dark ones). Beta-carotene is probably the most rich in carrots. I believe average people with healthy diet habbit (having both vegetables and meat) have sufficient intake of vitamin A.
Please note other carotinoids such as lycopene (abundant in tomato), lutein, and zeaxanthin are thought to have antioxidative effects, they don't turn to vitamine A. People are now taking these in addition to beta carotene. Nevertheless, studies had not shown definite effects on major health outcomes (e.g., heart disease, cancer etc.) I just briefly read a book called vegeterian. A billion dollar business.
The question here is whether VA-fortification will help poor kids in poor areas. I believe it probably will but very limited. For those areas having VA-insufficienct disease, they also don't have enough other complementary foods such as meat or eggs. They are likely iron-insufficiency, selium-insufficiency, vitamine E insufficiency, and in particular protein insufficiency.
I think the case when VA-insufficiency is most sever is poor people eat rice and the only dish available is hot pepper or pickle, which used to be my major food style in winter long time ago. :-)
Overall, rice is not a nutrient-rich food, in particular after extensive washing. I notice that in southern China, they want to make rice look bright and white, which essentially left only carbohydrate in rice. Sticky rice. :-)