客户服务: +852 5819-7639   |   客户支持   |   关于我们
Share分享并赚取10美金
复制并分享这个含有您奖励代码的页面,您的被推荐人将享受优惠并且您将赚取10美金。 更多信息
$5.00 OFF to New Customers : Use SAVEME5
 购物车
购物车中的商品 数量 价格
小计: HK$ 0.00

Learn all about Vitamin A

Also indexed as: A Vitamin, Retinol (Vitamin A)
Vitamin A: Main Image

How to take Vitamin A

For most people, up to 25,000 IU (7,500 mcg) of vitamin A per day is considered safe. However, people over age 65 and those with liver disease should probably not supplement with more than 15,000 IU per day, unless supervised by a doctor. In women who could become pregnant, the maximum safe intake is being re-evaluated. However, less than 10,000 IU (3,000 mcg) per day is generally accepted as safe. There is concern that larger intakes could cause birth defects. Whether the average person would benefit from vitamin A supplementation remains unclear.

Where to Find It

Liver, dairy products, and cod liver oil are good sources of vitamin A. Vitamin A is also available in supplement form.

Possible Deficiencies

People who limit their consumption of liver, dairy foods, and beta-carotene-containing vegetables can develop a vitamin A deficiency. Extremely low birth weight babies (2.2 pounds or less) are at high risk of being born with a deficiency, and vitamin A shots given to these infants have been reported in double-blind research to reduce the risk of lung disease. The earliest deficiency sign is poor night vision. Deficiency symptoms can also include dry skin, increased risk of infections, and metaplasia (a precancerous condition). Severe deficiencies causing blindness are extremely rare in Western societies.

Less severe deficiencies are more likely to occur with a variety of conditions causing malabsorption. A high incidence of vitamin A deficiency in people infected with HIV has also been reported. People with hypothyroidism have an impaired ability to convert beta-carotene to vitamin A. For this reason, some doctors suggest taking supplemental vitamin A (perhaps 5,000–10,000 IU per day) if they are not consuming adequate amounts in their diet.

Very old people with type 2 diabetes have shown a significant age-related decline in blood levels of vitamin A, irrespective of their dietary intake.



Vitamin A Benefits
Here is what people are saying about the benefits of Vitamin A.
Now Foods Vitamin A
Read Reviews >
BioTech Pharmacal A-25
Read Reviews >
Now Foods Vitamin A
Read Reviews >
Now Foods Vitamin A
Read Reviews >
Read more Vitamin A benefits >

Copyright © 2019 Aisle7.

折扣优惠
加入
eVitamins.com, © 版权所有 1999-2019。All Rights Reserved. eVitamins, LLC

本网站陈述的或从本网站出售的保健类产品,没有经过本网站或美国食品与药品管理局评估。他们不能代替药物或被用于诊断,治疗,治愈或预防任何疾病。本站提供的信息只作信息交流使用。如果您有任何健康相关的问题,或对服用所购买的膳食补充、保健品或其他产品有任何疑惑,请及时咨询有相关资质的医疗专业人士。

eVitamins, LLC - 6833 Auburn, Utica, MI 48317 USA - 1-888-222-6056


隐私条例 | 使用条款