视频文本

Copper is a mineral that our bodies need from enzymatic processes
人体需要铜完成酶的作用
yet not all the functions of copper are completely understood.
但铜的全部功能还不为我们所知，
Food sources for copper include organ meats such as liver and shellfish, nuts, seeds, legumes and dried fruits.
铜的食物来源包括肝等动物内脏，贝类，坚果，种子，豆类和干果，
The RDA for copper is 900 micrograms.
铜的RDA是900毫克
Although not all the functions of copper in our physiology are understood,
虽然我们并不知道铜在生理机能中的全部作用，
if we are deficient in copper anemia and bone abnormalities can result.
体内缺乏铜会导致贫血和骨骼异常
Zinc has a role in energy metabolism, tissue formation and alcohol detoxification in our bodies,
锌对于人体的能量代谢，组织生成和酒精解毒有其作用，
as it is a cofactor for certain enzymes that perform these functions.
因为它是完成这些功能的酶的辅助因素

Zinc is also necessary for sexual maturation and our ability to taste and smell.
性成熟以及味觉和嗅觉功能也需要锌，
Sources for zinc include oysters, wheat germ, liver and whole grains.
锌主要来源于牡蛎，麦芽，肝和整粒谷物
The RDA for zinc is 11 micrograms for males and 8 micrograms for females.
对于男性，锌的RDA为11毫克对于女性是8毫克，
There are numerous products on the market containing zinc that are advertised as cold treatments.
市场上有无数含锌产品，广告称可以治感冒，
Zinc does kill bacteria in a petri dish
在培养皿中锌确实能杀死细菌，
but it is not clear that it can also work in the body.
但是在体内是否如此并不清楚，
Zinc concentrations in cells and the blood are very carefully controlled
细胞和血液中的锌浓度受到精细控制，
because unbound zinc would kill cells.
因为过量的锌会杀死细胞，
Because zinc is a toxic metal high intakes in supplements should be avoided
由于锌是有毒金属元素应该避免过高的补充摄取
especially since there is no good scientific evidence for efficacy in cold therapy.
尤其是目前并没有科学证据证明锌有治疗感冒的作用，
The main role for selenium in the body is as part of the anti-oxidant enzyme glutathione peroxidase.
人体中硒的主要作用是作为抗氧化酶
Because of this role selenium has been linked to lower levels of certain types of cancer.
谷胱甘肽过氧化物酶的组成成分由于硒有这种作用，认为它和某些早期癌症有一定联系，
A current study is focused on selenium and prostate cancer for example.
比如最近就有研究着眼于硒和前列腺癌，
Food sources for selenium include grains, meat, poultry, fish or dairy products.
硒的食物来源有谷物，肉类，禽类，鱼和奶制品
However, selenium levels in food depend on where the food originated.
但是食物中硒的含量取决于食物来自哪里，
Soils that are deficient in selenium will yield crops that have lower levels of selenium.
缺乏硒的土壤长出的作物中含硒量就低
For example areas of Nebraska and North Dakota have high levels of selenium in the soil.
比如内布拉斯加州和北达科他州地区的土壤中含硒量高
The people in these areas have correspondingly high levels of the mineral in their diet.
这些地区的人口饮食中就有更多的硒，
In contrast parts of Russia and China have low levels in the soil
相反，俄国和中国的一些地区土壤含硒量少，
and more cases of deficiency occur in residents of those areas.
那些地区居民中就有更多缺硒的情况
The RDA for selenium is 55 micrograms which is readily attainable through diet.
硒的RDA是55毫克，通过正常饮食就能轻松获得，
Supplementation of this mineral is not necessary to meet the RDA.
不需要额外补充硒来达到这一RDA
These fascinating minerals play important roles in the physiology of our body.
这些神奇的矿物质在我们身体的生理机能中发挥重要作用，
New information about these minerals is still being investigated.
关于这些矿物质还有更多信息正在研究中
Minerals are present in most foods
大部分食物中都含矿物质
and the RDAs can usually be met by eating a balanced diet containing a variety of foods.
通过平衡饮食，兼顾各种食物就能达到这些RDA的要求

视频及简介

视频简介：

本节课介绍矿物质（无机盐），依次讲了钙、镁、钾、钠、铁、铜、锌和硒的作用、缺乏带来的影响、以及如何从食物中获取足够的矿物质。