怪不怪，十九世纪流行的佝偻病又重现美国
路透社芝加哥健康消息 在芝加哥召开的美国儿科学会会议上，研究人员报告，由维生素D缺乏引起的佝偻病，在婴幼儿中的发病率正在增加。
美国儿科学会营养委员会主席苏珊·贝克博士说，为了降低该病的发病风险，美国儿科学会有可能建议给所有母乳喂养的婴儿补充维生素D。不过这一建议在未来的18个月里还不会形成正式条文。尽管如此，专家们还是认为，母乳仍是婴儿最好的食物来源，而且研究发现用牛奶等配制成的强化食品并不比母乳好。
目前尚不清楚究竟美国有多少婴幼儿患佝偻病，因为佝偻病不要求向美国疾病控制和预防中心报告。然而，来自乔治亚州和北卡罗来纳州的2份报告指出，佝偻病的发展呈现令人担忧的趋势，美国疾病控制和预防中心正在就此进行调查。
其中一份报告显示，过去十年北卡罗来纳州共发现30例重度佝偻病，且60%的病例发生于最近18个月。所有患儿都是用纯母乳喂养的非裔美国人的婴儿。部份严重的患儿甚至出现了明显的骨骼畸形和抽搐。在乔治亚州，美国疾病控制和预防中心在1997年1月至1999年6月间共发现6例年龄介于7-21个月的重度佝偻病患儿，这些患儿均用母乳喂养了至少7-19个月，其中一例患儿在断奶后饮用未经强化的代乳品。这些病例情况非常严重，医生怀疑可能还有更多的轻症患儿未被发现。
, http://www.100md.com
佝偻病是一种“骨基质钙化不足”性疾病，患此病时，骨骼变得软弱，典型佝偻病患儿的腿骨向外弯曲，导致骨骼畸形，严重病例甚至发生抽搐。在十九世纪后期，有50%五岁以下的儿童患佝偻病。这种疾病在今天的美国十分罕见。但如今佝偻病病例的数目令人担忧，这驱使研究人员努力寻找导致这种疾病增多的原因。
原因之一可能是由于有越来越多的人对婴儿采取防晒措施。而阳光照射是维生素D的首要来源。肤色深的婴儿患佝偻病的危险性特别大，因为他们的皮肤色素水平高，限制了由阳光照射启动的维生素D的合成。但是，研究人员警告说，这并不意味着你现在就要在正午时候带你的婴儿到海滩上暴晒。儿童仍然应该避免日晒，否则有患皮肤癌的危险。
维生素D的其他来源主要是食物，如某些鱼肉、哺乳动物的肝脏、强化食品如牛奶和某些谷类食品，还见于用添加维生素D饲料喂养的母鸡的鸡蛋黄。但遗憾的是，人乳中只有很少量的维生素D，并且即使增加哺乳母亲维生素的摄入量也用处不大。因为只有给母亲服用接近中毒剂量的维生素D才能增加其乳汁中维生素D的含量。可见，对于母乳喂养的且缺乏阳光照射的婴儿，这不是一个合理的解决途径。
, 百拇医药
专家认为，无论是什么种族，解决的方法都是给母乳喂养的婴儿补充维生素D。父母应该给稍大的孩子喝牛奶，在给孩子选择其他饮料时，应选择相应牛奶营养的。许多父母选择给孩子喂豆浆和米汤，这些食物不一定经过维生素D强化。父母需要选择营养全面的豆制品，这类食品市面有售。
也有专家认为，婴儿配方食品都是经过维生素D强化的，食用这类食物的婴儿不需补充维生素D，因为摄入过多的维生素D会中毒。母乳和婴儿配方食品混合喂养的婴儿一般也不需要补充维生素D。目前指导方针的具体细节还未确定。
美国疾病控制和预防中心的流行病学家凯尔利·桑伦博士说，有关的建议有待完整，但现在还未进行讨论。父母目前能做的最好的事情是咨询儿科医生。进行母乳喂养的母亲应该与你的临床医生谈谈维生素D。孩子断奶时，也应该和与医生讨论转用哪种牛奶为好。
Bone Disease on the Rise in Infants, Toddlers
, 百拇医药
CHICAGO (Reuters Health) - Rickets--a bone disorder caused by vitamin D deficiency--appears to be on the rise in infants and toddlers, due in part to an increase in the use of sunscreen, researchers reported here Sunday at the American Academy of Pediatrics meeting.
To offset this risk, the American Academy of Pediatrics (AAP) will probably recommend that all breast fed infants receive vitamin D supplements, although no formal recommendation is expected for 18 months, said Dr. Susan Baker, chair of the AAP‘s Committee on Nutrition. However, experts caution that breast milk is still the best food source for infants and the findings do not suggest that formula is superior to breast milk.
, 百拇医药
It is not clear exactly how many infants or young children have rickets, because the ailment is not routinely reported to the Centers for Disease Control and Prevention (news - web sites) (CDC). However, two reports from Georgia and North Carolina appear to point to a disturbing trend, which the CDC is currently investigating.
Thirty cases of severe rickets have been seen in the past 10 years in North Carolina, but 60% of those cases occurred in the last 18 months, according to one report. All the cases occurred in African-American babies who were exclusively breast fed, and the cases were so severe the infants sometimes had obvious bone abnormalities or even seizures. In Georgia, the CDC found six cases of severe rickets occurred in youngsters 7-21 months of age between January 1997 and June 1999. The children were breast-fed for at least 7 to 19 months and in one instance, a child drank an unfortified milk substitute after being weaned.
, http://www.100md.com
These cases were especially severe, but doctors suspect there may be many more mild cases of the illness.
``Any time there‘s a case report of a clinically apparent deficiency disease it‘s likely there were more children that were deficient that we weren‘t able to pick up,‘‘ Baker said. ‘‘Having seen that number of rickets is a bit a worry for us and led many of us to try to understand why the cases seemed to be increasing.‘‘
Rickets is a ``failure of the bony matrix to mineralize,‘‘ Baker said. Bones become soft and weak, and typically the legs bow outwards. The condition can lead to skeletal abnormalities, and in severe cases, seizures. While 50% of children under the age of five had the condition in the late 1800s, the condition was thought to be relatively rare now in the US.
, http://www.100md.com
One reason may be the trend towards protecting babies from sunshine, the primary source of vitamin D. The risk is especially great for darker skinned infants, who have higher levels of skin pigment, which limits the amount of vitamin D production triggered by the sun.
However, this does not mean that you should now expose your baby on the beach at high noon, the researchers cautioned. Because of the risk of skin cancer, children should still be protected from sunlight, Baker said.
, 百拇医药
There are other sources of vitamin D, mainly dietary. The vitamin can be found in the flesh of some fish, the liver of some mammals, fortified foods such as milk and certain cereals. It can also be found in egg yolks from hens fed a vitamin D-supplemented diet, though not in other eggs.
``Human milk unfortunately has very little vitamin D,‘‘ Baker said. ``And having breast-feeding moms up their intake of the vitamin doesn‘t appear to help. If you supplement mothers with vitamin D you must give then almost toxic levels consistently of vitamin D for them to increase the amount of vitamin D in their milk. So this is not a reasonable way to approach infants who are being breast fed who are not exposed to sunlight.‘‘
, http://www.100md.com
The answer may to provide breast-fed infants--regardless of race--vitamin D supplements.
And parents should make sure that older children are given milk, Baker said. If parents choose to give their youngster another type of beverage, they should choose one that is ‘‘nutritionally comparable,‘‘ Baker said.
Many parents choose to give soy milk or rice beverages, which are not always fortified with vitamin D, she said. Parents need to select a ``soy product that is a complete food, there are some of them available,‘‘ Baker said.
, http://www.100md.com
Infant formulas are all fortified with vitamin D, and those infants should not be given vitamin D supplements, according to the experts. Too much vitamin D can be toxic, and supplementation is probably not necessary for babies fed a combination of breast milk and infant formula--though the AAP and the CDC have not yet determined the specifics of the guidelines.
``All of that would need to be sorted out, it hasn‘t been discussed,‘‘ said Dr. Kelley Scanlon, an epidemiologist at the CDC.
The best thing a parent can do is consult the pediatrician, she said. ``Talk to your clinician about vitamin D,‘‘ she advised breast-feeding moms. ``And when they are weaning they should also discuss with their clinician the milk they are transitioning to.‘‘, 百拇医药
美国儿科学会营养委员会主席苏珊·贝克博士说，为了降低该病的发病风险，美国儿科学会有可能建议给所有母乳喂养的婴儿补充维生素D。不过这一建议在未来的18个月里还不会形成正式条文。尽管如此，专家们还是认为，母乳仍是婴儿最好的食物来源，而且研究发现用牛奶等配制成的强化食品并不比母乳好。
目前尚不清楚究竟美国有多少婴幼儿患佝偻病，因为佝偻病不要求向美国疾病控制和预防中心报告。然而，来自乔治亚州和北卡罗来纳州的2份报告指出，佝偻病的发展呈现令人担忧的趋势，美国疾病控制和预防中心正在就此进行调查。
其中一份报告显示，过去十年北卡罗来纳州共发现30例重度佝偻病，且60%的病例发生于最近18个月。所有患儿都是用纯母乳喂养的非裔美国人的婴儿。部份严重的患儿甚至出现了明显的骨骼畸形和抽搐。在乔治亚州，美国疾病控制和预防中心在1997年1月至1999年6月间共发现6例年龄介于7-21个月的重度佝偻病患儿，这些患儿均用母乳喂养了至少7-19个月，其中一例患儿在断奶后饮用未经强化的代乳品。这些病例情况非常严重，医生怀疑可能还有更多的轻症患儿未被发现。
, http://www.100md.com
佝偻病是一种“骨基质钙化不足”性疾病，患此病时，骨骼变得软弱，典型佝偻病患儿的腿骨向外弯曲，导致骨骼畸形，严重病例甚至发生抽搐。在十九世纪后期，有50%五岁以下的儿童患佝偻病。这种疾病在今天的美国十分罕见。但如今佝偻病病例的数目令人担忧，这驱使研究人员努力寻找导致这种疾病增多的原因。
原因之一可能是由于有越来越多的人对婴儿采取防晒措施。而阳光照射是维生素D的首要来源。肤色深的婴儿患佝偻病的危险性特别大，因为他们的皮肤色素水平高，限制了由阳光照射启动的维生素D的合成。但是，研究人员警告说，这并不意味着你现在就要在正午时候带你的婴儿到海滩上暴晒。儿童仍然应该避免日晒，否则有患皮肤癌的危险。
维生素D的其他来源主要是食物，如某些鱼肉、哺乳动物的肝脏、强化食品如牛奶和某些谷类食品，还见于用添加维生素D饲料喂养的母鸡的鸡蛋黄。但遗憾的是，人乳中只有很少量的维生素D，并且即使增加哺乳母亲维生素的摄入量也用处不大。因为只有给母亲服用接近中毒剂量的维生素D才能增加其乳汁中维生素D的含量。可见，对于母乳喂养的且缺乏阳光照射的婴儿，这不是一个合理的解决途径。
, 百拇医药
专家认为，无论是什么种族，解决的方法都是给母乳喂养的婴儿补充维生素D。父母应该给稍大的孩子喝牛奶，在给孩子选择其他饮料时，应选择相应牛奶营养的。许多父母选择给孩子喂豆浆和米汤，这些食物不一定经过维生素D强化。父母需要选择营养全面的豆制品，这类食品市面有售。
也有专家认为，婴儿配方食品都是经过维生素D强化的，食用这类食物的婴儿不需补充维生素D，因为摄入过多的维生素D会中毒。母乳和婴儿配方食品混合喂养的婴儿一般也不需要补充维生素D。目前指导方针的具体细节还未确定。
美国疾病控制和预防中心的流行病学家凯尔利·桑伦博士说，有关的建议有待完整，但现在还未进行讨论。父母目前能做的最好的事情是咨询儿科医生。进行母乳喂养的母亲应该与你的临床医生谈谈维生素D。孩子断奶时，也应该和与医生讨论转用哪种牛奶为好。
Bone Disease on the Rise in Infants, Toddlers
, 百拇医药
CHICAGO (Reuters Health) - Rickets--a bone disorder caused by vitamin D deficiency--appears to be on the rise in infants and toddlers, due in part to an increase in the use of sunscreen, researchers reported here Sunday at the American Academy of Pediatrics meeting.
To offset this risk, the American Academy of Pediatrics (AAP) will probably recommend that all breast fed infants receive vitamin D supplements, although no formal recommendation is expected for 18 months, said Dr. Susan Baker, chair of the AAP‘s Committee on Nutrition. However, experts caution that breast milk is still the best food source for infants and the findings do not suggest that formula is superior to breast milk.
, 百拇医药
It is not clear exactly how many infants or young children have rickets, because the ailment is not routinely reported to the Centers for Disease Control and Prevention (news - web sites) (CDC). However, two reports from Georgia and North Carolina appear to point to a disturbing trend, which the CDC is currently investigating.
Thirty cases of severe rickets have been seen in the past 10 years in North Carolina, but 60% of those cases occurred in the last 18 months, according to one report. All the cases occurred in African-American babies who were exclusively breast fed, and the cases were so severe the infants sometimes had obvious bone abnormalities or even seizures. In Georgia, the CDC found six cases of severe rickets occurred in youngsters 7-21 months of age between January 1997 and June 1999. The children were breast-fed for at least 7 to 19 months and in one instance, a child drank an unfortified milk substitute after being weaned.
, http://www.100md.com
These cases were especially severe, but doctors suspect there may be many more mild cases of the illness.
``Any time there‘s a case report of a clinically apparent deficiency disease it‘s likely there were more children that were deficient that we weren‘t able to pick up,‘‘ Baker said. ‘‘Having seen that number of rickets is a bit a worry for us and led many of us to try to understand why the cases seemed to be increasing.‘‘
Rickets is a ``failure of the bony matrix to mineralize,‘‘ Baker said. Bones become soft and weak, and typically the legs bow outwards. The condition can lead to skeletal abnormalities, and in severe cases, seizures. While 50% of children under the age of five had the condition in the late 1800s, the condition was thought to be relatively rare now in the US.
, http://www.100md.com
One reason may be the trend towards protecting babies from sunshine, the primary source of vitamin D. The risk is especially great for darker skinned infants, who have higher levels of skin pigment, which limits the amount of vitamin D production triggered by the sun.
However, this does not mean that you should now expose your baby on the beach at high noon, the researchers cautioned. Because of the risk of skin cancer, children should still be protected from sunlight, Baker said.
, 百拇医药
There are other sources of vitamin D, mainly dietary. The vitamin can be found in the flesh of some fish, the liver of some mammals, fortified foods such as milk and certain cereals. It can also be found in egg yolks from hens fed a vitamin D-supplemented diet, though not in other eggs.
``Human milk unfortunately has very little vitamin D,‘‘ Baker said. ``And having breast-feeding moms up their intake of the vitamin doesn‘t appear to help. If you supplement mothers with vitamin D you must give then almost toxic levels consistently of vitamin D for them to increase the amount of vitamin D in their milk. So this is not a reasonable way to approach infants who are being breast fed who are not exposed to sunlight.‘‘
, http://www.100md.com
The answer may to provide breast-fed infants--regardless of race--vitamin D supplements.
And parents should make sure that older children are given milk, Baker said. If parents choose to give their youngster another type of beverage, they should choose one that is ‘‘nutritionally comparable,‘‘ Baker said.
Many parents choose to give soy milk or rice beverages, which are not always fortified with vitamin D, she said. Parents need to select a ``soy product that is a complete food, there are some of them available,‘‘ Baker said.
, http://www.100md.com
Infant formulas are all fortified with vitamin D, and those infants should not be given vitamin D supplements, according to the experts. Too much vitamin D can be toxic, and supplementation is probably not necessary for babies fed a combination of breast milk and infant formula--though the AAP and the CDC have not yet determined the specifics of the guidelines.
``All of that would need to be sorted out, it hasn‘t been discussed,‘‘ said Dr. Kelley Scanlon, an epidemiologist at the CDC.
The best thing a parent can do is consult the pediatrician, she said. ``Talk to your clinician about vitamin D,‘‘ she advised breast-feeding moms. ``And when they are weaning they should also discuss with their clinician the milk they are transitioning to.‘‘, 百拇医药