High concentration of vitamin A may lead to fracture because

A:A．elderly people are slow in digesting vitamin B:B．the absorption of excessive vitamin A makes people near-sighted. C:C．it helps produce cells that weaken the bones of human beings, D:D．vitamin A stays in human body for a long timid.

Passage Two
Protecting the heart, warding off cancer, easing the pain of arthritis -- the list of Vitamin E’s possible benefits keeps getting longer. Now, because of two new studies, some researchers say the nutrient is so critical for older people that everyone over 65 should consider taking a daily supplement.
The latest finding comes from nutrition and immunology respected: Vitamin E boosts the immune system in older people. In an eight-month study of 88 seniors, the scientists found that those taking at least 200 international units of Vitamin E daily had stronger immune responses than those taking little or none. Alzheimer’s disease. Researchers tracked 341 moderately senile patients. Those who popped 2,000 IU of Vitamin E took seven months longer to reach an advanced stage of the disease.
Rangit Kumar Chandra, a Vitamin E researcher at Memorial University of Newfoundland, Canada, says more studies are needed to learn who can benefit most and at what dose. Vitamin E thins the blood, so high doses can cause bleeding in people who also take blood thinning drags, even aspirin. Individuals with serious conditions should consult their doctors. But most people over 65, Chandra says, can take up to 200 IU with no side effects and great benefits.

What can you infer from the passage（）

A:Extremely high dose of Vitamin E can cause danger. B:With proper dose of Vitamin E old people could be safer from infectious disease. C:Researchers have proved that Vitamin E has no side effects. D:Individuals with serious conditions should consult their doctors.

Passage Two
Protecting the heart, warding off cancer, easing the pain of arthritis -- the list of Vitamin E’s possible benefits keeps getting longer. Now, because of two new studies, some researchers say the nutrient is so critical for older people that everyone over 65 should consider taking a daily supplement.
The latest finding comes from nutrition and immunology respected: Vitamin E boosts the immune system in older people. In an eight-month study of 88 seniors, the scientists found that those taking at least 200 international units of Vitamin E daily had stronger immune responses than those taking little or none. Alzheimer’s disease. Researchers tracked 341 moderately senile patients. Those who popped 2,000 IU of Vitamin E took seven months longer to reach an advanced stage of the disease.
Rangit Kumar Chandra, a Vitamin E researcher at Memorial University of Newfoundland, Canada, says more studies are needed to learn who can benefit most and at what dose. Vitamin E thins the blood, so high doses can cause bleeding in people who also take blood thinning drags, even aspirin. Individuals with serious conditions should consult their doctors. But most people over 65, Chandra says, can take up to 200 IU with no side effects and great benefits.

What's the main idea of the passage（）

A:People will be in perfect health if they take Vitamin E every day. B:Study showed that people who took Vitamin E regained their Flexibility. C:Vitamin E may help prevent Alzheimer's. D:Vitamin E offers a range of advantage if old people take proper dose of Vitamin E every day.

Passage Two
Protecting the heart, warding off cancer, easing the pain of arthritis -- the list of Vitamin E’s possible benefits keeps getting longer. Now, because of two new studies, some researchers say the nutrient is so critical for older people that everyone over 65 should consider taking a daily supplement.
The latest finding comes from nutrition and immunology respected: Vitamin E boosts the immune system in older people. In an eight-month study of 88 seniors, the scientists found that those taking at least 200 international units of Vitamin E daily had stronger immune responses than those taking little or none. Alzheimer’s disease. Researchers tracked 341 moderately senile patients. Those who popped 2,000 IU of Vitamin E took seven months longer to reach an advanced stage of the disease.
Rangit Kumar Chandra, a Vitamin E researcher at Memorial University of Newfoundland, Canada, says more studies are needed to learn who can benefit most and at what dose. Vitamin E thins the blood, so high doses can cause bleeding in people who also take blood thinning drags, even aspirin. Individuals with serious conditions should consult their doctors. But most people over 65, Chandra says, can take up to 200 IU with no side effects and great benefits.

The best title for the passage is （）

A:Vitamin E Scores for Old People B:Vitamin E Fights Cancer C:You Need Vitamin E D:How to Keep Healthy

Passage Two
Protecting the heart, warding off cancer, easing the pain of arthritis -- the list of Vitamin E’s possible benefits keeps getting longer. Now, because of two new studies, some researchers say the nutrient is so critical for older people that everyone over 65 should consider taking a daily supplement.
The latest finding comes from nutrition and immunology respected: Vitamin E boosts the immune system in older people. In an eight-month study of 88 seniors, the scientists found that those taking at least 200 international units of Vitamin E daily had stronger immune responses than those taking little or none. Alzheimer’s disease. Researchers tracked 341 moderately senile patients. Those who popped 2,000 IU of Vitamin E took seven months longer to reach an advanced stage of the disease.
Rangit Kumar Chandra, a Vitamin E researcher at Memorial University of Newfoundland, Canada, says more studies are needed to learn who can benefit most and at what dose. Vitamin E thins the blood, so high doses can cause bleeding in people who also take blood thinning drags, even aspirin. Individuals with serious conditions should consult their doctors. But most people over 65, Chandra says, can take up to 200 IU with no side effects and great benefits.

More study are needed to learn （）

A:Vitamin E's side effects B:who will gain the greatest advantages by taking Vitamin E C:Vitamin E's other benefits D:how Vitamin E cuts risks of heart attack

Vitamins are important to our health．Difierent vitamins are found in difierent foods．grains．vegetables and fruits，fish and meat，eggs and milk products．So which foods should be eaten to get enough of the vitamins our bodies needLet us look at some important vitamins for the answer．
Vitamin A helps prevent skin and other tissues from becoming dry．People who do not get enough Vitamin A cannot see well in darkness．They may develop a condition that dries the eyes．This can result in infections and lead to blindness．Vitamin A is found in fish liver oil．It is also in the yellow part of eggs．Sweet potatoes．carrots and other darkly colored fruits and vegetables contain substances that the body can change into Vitamin A．
Vitamin B is also called thiamine(硫胶)．Thiamine changes starchy foods jnto energy．It also helps the heart and nervous system work smoothly．Without it．we would be weak and would not grow．We also might develop beriberi(脚气病)．Thiamine is found not iust in whole grains like brown rice．but also jn other foods．These include beans and peas．nuts．and meat and fish．
Vitamin C is needed for strong bones and teeth．and for healthy blood passages．It also helps wounds heal quickly．The body stores little Vitamin C．So we must get it every day in foods such as citrus fruits，tomatoes and uncooked cabbage．
Vitamin D increases levels of the element calcium(铲)in the blood．Calcium is needed for nerve and muscle cells to work normally．It is also needed to build strong bones．VitaminD prevents the children’s bone disease rickets(佝偻痫)．Ultraviolet light from the sun changes a substance in the skin into vitamin D Fish liver oil also contains vitamin D．In some countries．milk producers add vitamin D to milk so children will get enough．
Vitamin K is needed for healthy blood．It thickens the blood around a cut to stop bleeding．Bacteria in the intestines f肠道)normally produce vitamin K．It can also be found in pork products．1iver and in vegetables like cabbage．kale and spinach．
______is able to change rice and wheat into energy

A:Vitamin C B:Vitamin K C:pork products D:Vitamin BI

Vitamin D helps bones and muscles grow strong and healthy. Low levels of vitamin D can lead to problems like rickets and osteoporosis. Rickets is a deformity mainly found in children. Osteoporosis is the thinning of bone, a common problem as people, especially women, get older. Studies in recent years have suggested that vitamin D may also have other uses. Studies have shown that low levels of D may increase the risk of heart attacks in men and deaths from some cancers. Other studies have shown that people with rheumatic diseases often have low levels of D.
The easiest way to get vitamin D is from sunlight. The ultraviolet rays react with skin cells to produce the vitamin. But many people worry about skin cancer and skin damage from the sun. Also, darker skinned people produce less vitamin D than lighter skinned people. Production also decreases in older people and those living in northern areas that get less sunlight.
Not many foods naturally contain vitamin D. Foods with high levels include oily fish such as salmon, tuna and mackerel, and fish liver oils. Small amounts of D are found in beef liver, cheese and egg yolks. Most of the D in the American diet comes from foods like milk with the vitamin added.
These days, more doctors are testing for vitamin D levels in their patients. But as research continues, some experts worry that if people take too much D, it might act as a poison. Also, skin doctors warn people to be careful with sun exposure.
How much vitamin D does a healthy person need Nutrition experts who advise the American government set the current recommendations in nineteen ninety -seven. The daily amount is two hundred international units from birth through age fifty. Then it rises to four hundred I. U. s through age seventy, and six hundred for those seventy--one and older. But some groups say these amounts are not high enough.
Which of the following is NOT mentioned in this article

A:Too much Vitamin D may cause skin cancer. B:Sunlight is the easiest way to get vitaminD. C:Few kinds of food naturally contain vitamin D:D. The older people need more vitamin D than the yout