You may know all about vitamin C, but do you know why vitamin D is also important to your body? Experts from the Children’s Hospital in Boston, US, have said that some teens don’t get enough of this important nutrient¹. 

　　Vitamin D is necessary to develop healthy bones. It is produced by the body with the help of sunlight. It can also be found in certain foods and drinks, such as livers² and eggs. However, it is difficult to get enough vitamin D from food alone, which means enjoying the sunshine is very important. 

　　The doctors who ran the study tested 307 adolescents to discover how much vitamin D was in their blood. They found that 74 of the children tested-nearly 25 percent-had vitamin D deficiency³. Of those 74, 14 were severely⁴ short of the nutrient. 

　　The doctors also found that the amount of the vitamin found in a child’s blood was affected⁵ by a number of factors. Vitamin D levels drop in winter, probably because less time is spent outside in the sunlight. Diet was also a key factor. 

　　Even skin colour has an influence, as people with darker skin find it more difficult to produce the vitamin. 

　　Vitamin D deficiency can lead to many health problems for both children and adults. It is also believed that low levels of it can cause depression.

　　辅助阅读：

　　美国波士顿儿童医院的专家称，有些青少年不能获取足够的维生素D。缺乏维生素D会引起很多健康问题。维生素D是骨质健康成长所必需的。维生素D含量低还可能引起抑郁症。而阳光有助于人体生成维生素D。研究发现，某些食物（如动物肝脏和鸡蛋）和饮料含有维生素D，但人体单纯从食物中不能获取足够的维生素D。所以，晒太阳对人体来讲非常重要。

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