题目内容：

    Vitamin D is necessary for bone-building, immune function, blood sugar control, positive mood and more. 1. The lower your vitamin D level is, the higher your risk of death from ally cause will be. However, it’s not a great idea to just take a supplement (补品) off the drugstore shelf and start taking it.

Since many of us have an inadequate amount vitamin D, also known as the “sunshine vitamin”, doctors will often give us high levels of D supplements, with doses ranging from 2,000 to 10,000 IU (International Units) per day, up to 50,000 IU per week and sometimes even more. 2. Very big doses ( 剂量) of vitamin D can cause a build-up of calcium ( 钙) in the blood, which leads to poor appetite, weakness, weight loss or other diseases. Here’s the bigger issue: 3. A build-up of stored vitamin D cart cause avoidable problems, leading to problems such as kidney stones.

4. The National Institutes of Health set the Recommended Dietary Allowance for vitamin D at 600 IU daily for babies, children, and adults up to 70 years old. Adults aged 71 and older need 800 IU, since the ability to absorb vitamin D drops with age. Because the fat cells take vitamin D up, making it less available for use by tile body, 5.

Though you’ll get a bit of vitamin D from foods—including fatty fish, beef liver, cheese, milk and so on—the amounts are so small that there’s little need to worry that they’ll put you over the daily dose.

A.It can help prevent many diseases.

B.We can actually reduce the risk of death.

C.people who are fat may also need more vitamin

D.any extra intake of vitamin D can get stored in the body.

E.But like all good things, it’s possible to get too much of it.

F.The average daily recommended amounts vary based on your age.

G.Vitamin D should be supplemented carefully despite its importance.