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 nutrient. 

    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 livers 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 deficiency. Of those 74, 14 were severely short of the nutrient. 

    The doctors also found that the amount of the vitamin found in a child’s blood was affected 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. 

    美國(guó)波士頓兒童醫(yī)院的專(zhuān)家稱(chēng)，有些青少年不能獲取足夠的維生素D。缺乏維生素D會(huì)引起很多健康問(wèn)題。維生素D是骨質(zhì)健康成長(zhǎng)所必需的。維生素D含量低還可能引起抑郁癥。而陽(yáng)光有助于人體生成維生素D。研究發(fā)現(xiàn)，某些食物（如動(dòng)物肝臟和雞蛋）和飲料含有維生素D，但人體單純從食物中不能獲取足夠的維生素D。所以，曬太陽(yáng)對(duì)人體來(lái)講非常重要。