Vitamins, like minerals, are chemicals. There is absolutely not difference (1)______ in the chemical structure of the nature vit

admin2014-01-09  40

问题     Vitamins, like minerals, are chemicals. There is absolutely not difference (1)______
in the chemical structure of the nature vitamin C and the chemical structure (2)______
of the synthetic vitamin C. Also, while most substances are harmless at very low (3)______
level of intake, all substance — even the elements that are essential to
life — can be dangerous if you overdo them. Take water for example.
Six or eight glasses a day will keep your body in good
fluid balance. But you can also be drown (4)______
in it. Some people argue that since individuals vary greatly (5)______
their need for nutrients, it cannot necessarily be stated any given (6)______
amount is too much; that is all relative. But since there is little solid
information on what is the optimal intake of any essential nutrient in
healthy individuals, it would be impossible to give
guidelines that take these proportional needs into the (7)______
account. Just as with other drugs, the relation to (8)______
different vitamin dosages varies, with some people better
able than others to tolerate large
amounts. While we do know that very specifically what the toxic level (9)______
is for vitamins A and D, we are far less sure about vitamin E,
even though it, too, is fat-soluble, and
we still don’t understand the water-soluble vitamin, the C (10)______
and the B groups, which the body can’t store.
(3)

选项

答案at∧a

解析
转载请注明原文地址:https://jikaoti.com/ti/t47YFFFM
0

最新回复(0)