时间:2018-12-15 作者:英语课 分类:VOA慢速英语2009年(九)月


英语课

This is the VOA Special English Health Report.


Vitamin D helps bones and muscles grow strong and healthy. Low levels of vitamin D can lead to problems like rickets 1 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 2 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 3, tuna and mackerel, and fish liver oils. Boston University researchers reported in two thousand seven that farmed salmon had a lot less vitamin D than wild salmon.


Small amounts of D are found in beef liver, cheese and egg yolks. And some people take dietary supplements containing the vitamin. But 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.


The nutrition experts are taking another look at how much vitamin D and calcium 4 people should get. The Institute of Medicine of the National Academies expects to release a report by this coming May.


And that's the VOA Special English Health Report, written by Caty Weaver 5. I'm Bob Doughty 6.



1 rickets
n.软骨病,佝偻病,驼背
  • A diet deficient in vitamin D may cause the disease rickets.缺少维生素D的饮食可能导致软骨病。
  • It also appears to do more than just protect against rickets.除了防止软骨病,它还有更多的功能。
2 lighter
n.打火机,点火器;驳船;v.用驳船运送;light的比较级
  • The portrait was touched up so as to make it lighter.这张画经过润色,色调明朗了一些。
  • The lighter works off the car battery.引燃器利用汽车蓄电池打火。
3 salmon
n.鲑,大马哈鱼,橙红色的
  • We saw a salmon jumping in the waterfall there.我们看见一条大马哈鱼在那边瀑布中跳跃。
  • Do you have any fresh salmon in at the moment?现在有新鲜大马哈鱼卖吗?
4 calcium
n.钙(化学符号Ca)
  • We need calcium to make bones.我们需要钙来壮骨。
  • Calcium is found most abundantly in milk.奶含钙最丰富。
5 weaver
n.织布工;编织者
  • She was a fast weaver and the cloth was very good.她织布织得很快,而且布的质量很好。
  • The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。
6 doughty
adj.勇猛的,坚强的
  • Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质:脾气倔强,性格刚强。
  • The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。
学英语单词
-teenth
angular motion
appointment-only
ash-greys
autocratic leader
automatic data processing systems
Ban Nong Yang
Bandwidth-on-demand
bare the metal
basilar membranae
bonnett
catalogable permanent file
cheek retractor
chloroethylaminoanthraquinones
classical-styles
closure of simplex
collective body
community residents
copius
coraebus aesopus
crummy
cystomyxoma
dispension
disproportionateness
distrbuted processing
electro-gas arc welding
excitaton source
exhibition expenditures
false myxoma
fear-stricken
fibre grease
firiming agent
fix things up
fluidized layer
forage for
fund levy
go on an outing
graphic kernel system
gravity spectrum
gravity tectonics
green cormorant
guilt-trip
heliocentric declination
heterodyne interference
high speed steel end mill
Igo
in one piece nozzle
income-expenditures
interpretation of dreams
island-dwellers
Knelston
laid lower
lead crown glass
Leo III
linen fiber
load up on sth
lyme-hound
make gains
manufacturer's rep
mechano-chemical system
medical diagnostic radiation
metallographs
Middleton Stoney
missel-bird
Mogogelo
noas
note to the accounts
number identification
off-colo(u)r product
oystered
pal(a)eohydrology
Palespotted
pasta rocket
pasteur pipet
permineralised
planetary landing
plant room
plumbaginaceous
pulsed lasers
re-taining part of the extra profit
reed sweep
Resia
ring-a-ring
screen scarifier
sewerage of separate system
site autonomy
taint-hook
take springs out from
testing of soil
tetrazoles
think no small bear of
Tolbukhinski Okrǔg
toona sureni(bl.)merr.
total color blindness
Tristars
wages fund
wooden bridge
written calculation
yeast-liked
zero-zero gel
zhishi xiebai guizhi decoction