Welcome to Healthy Diet Research Guide
Liquid Nutritional Supplement Article
This is a selection made from among articles on Liquid Nutritional Supplement. For a permanent link to this article, or to bookmark it for future reading, click here.
Vitamin A Article:
from:Vitamin A is one of many essential vitamins you need in your diet in order to promote a healthy lifestyle. Vitamin A is a family of fat-soluble compounds that play an important role in vision, bone growth, reproduction, cell division, and cell differentiation. It helps to regulate the immune system, which helps to keep you healthy by producing white blood cells that destroy harmful bacteria and viruses. Vitamin A may also help lymphocytes, a specific type of white blood cell, fight infections more effectively. Vitamin A also helps to promote healthy surface linings of the eyes and the respiratory, urinary, and intestinal tracts. Vitamin A also helps to maintain the integrity of the skin and the mucous membranes, which help to keep bacteria and viruses from entering your body and making you ill.
Retinol is one of the most active forms of Vitamin A and it can be found in liver, whole milk, whole eggs, margarine, and in some fortified food products like fortified breakfast cereals. It's also known as preformed Vitamin A. Retinol can be converted into retinal and retinolic acid, other active forms of the Vitamin A family.
Another form that can be converted to Vitamin A is Provitamin A carotenoids. They are darkly colored pigments found in plant foods. Common carotenoids found in foods include beta-carotene, alpha-carotene, lutein, zeaxanthin, lycopene, and cryptoxanthin. Of these, beta-carotene can be easily and efficiently converted to Vitamin A, while alpha-carotene and beta-cryptoxanthin are convertible to Vitamin A, but only half as efficiently as beta-carotene. The Institute of Medicine recommends eating carotenoid-rich fruits and vegetables for their health-promoting benefits, especially carrots, cantaloupes, sweet potatoes, and spinach.
Animal sources of vitamin A are well-absorbed and used efficiently by the body, whereas plant sources of Vitamin A aren't absorbed as well.
The Daily Value (DV) for Vitamin A, according to the Food and Nutrition Board of the National Academy of Sciences, is 5,000 International Units (IUs.) An international unit is the amount of a substance (such as a vitamin) that produces a specific effect, as defined by an international body (like the Food and Nutrition Board of the National Academy of Sciences) and accepted internationally. IUs are normally used on nutrition labelling for Vitamin A. One IU is equivalent to 0.3 micrograms (mcgs) of retinol, 0.6 mcg of beta-carotene, or 1.2 mcg of other provitamin-A carotenoids (like you find in fruits and vegetables.)
Another way of measuring how much you should have of each vitamin is measured by the Recommended Dietary Allowance (RDA.) RDAs for Vitamin A are measured in micrograms (mcg) of Retinol Activity Equivalents (RAE) to account for the different biological activities of retino and provitamin A carotenoids. For comparison, 1 RAE = 3.3 IU.
1- to 3-year old children should have 300 mcg RAE or 1,000 IU of Vitamin A.
4- to 8-year old children should have 400 mcg RAE or 1,320 IU of Vitamin A.
9- to 13-year old children should have 600 mcg RAE or 2,000 IU of Vitamin A.
Men who are 14+ years old should have 900 mcg RAE or 3,000 IU of Vitamin A.
Women who are 14+ years old should have 700 mcg RAE or 2,310 IU of Vitamin A.
Pregnant women who are 14-18 years old should have 750 mcg RAE or 2,500 IU of Vitamin A.
Pregnant women who are 19+ years old should have 770 mcg RAE or 2,565 IU of Vitamin A.
Vitamin A is a fat-soluble vitamin, which means that it accumulates within the fat stores of the body and within the liver. If taken in large amounts (660,000 IUs for adults and 330,000 IUs for children,) Vitamin A can be toxic, leading to loss of appetite, irritability, fatigue, weakness, and vomiting. Infants can suffer growth retardation of the long bones, like the femur in the leg, and premature epiphyseal bone closing. Adults can have several ailments from prolonged Vitamin A usage, including dry and itchy skin, dry and brittle fingernails, hair loss, headaches, fatigue, depression, liver damage, and a loss of appetite. However, vitamin A deficiency can lead to night blindness, a condition called hyperkeratosis, which is a goose bump-like appearance on the skin caused by excessive production of keratin (a protein found in the skin) that blocks hair follicles, which can lead to hair loss, and vitamin A deficiency can lead to the diminishing of the body's ability to fight infections. The cells lining the lungs lose their ability to remove disease-causing microorganisms. This may be why there is an association with pneumonia in vitamin-A deficient people. Therefore, it is important to get the right amount of Vitamin A in your diet.
For more information, go here:
http://www.google.com/search?hl=en&lr=&defl=en&q=define:INTERNATIONAL+UNIT&sa=X&oi=glossary_definition&ct=title
http://www.google.com/search?hl=en&lr=&defl=en&q=define:Recommended+Daily+Allowance&sa=X&oi=glossary_definition&ct=title
http://www.whfoods.com/genpage.php?tname=nutrient&dbid=106
Liquid Nutritional Supplement News
No relevant info was found on this topic.