Posts Tagged ‘night blindness’

Information About Vitamin a

Friday, December 18th, 2009

 

A

 

Introduction

 

Often touted as a miracle , A is the secret to great skin, higher and holistic growth. A is a powerful that also improves , helps strengthen bones, protects the body from heart related diseases, alleviates acne and conditions, reduces wrinkles, alleviates and helps improve measles and conditions.

 

Functions within the body

 

, which is a by-product of A, is responsible for helping the eyes adapt to dark environments easily. Therefore, regular intake of A can help prevent a condition known as ‘.’   acids help regulate and expressions within the body and an of A helps preserve the physiological characteristics of cells in the body. A is also an effective agent against any infections as it helps to strengthen the mucous linings, skin, urinary tract and , so forming the primary against most infections. Whilst A may be needed for proper in the body, too little or too much of this can cause defects in a foetus.   corpuscles originate from stem cells, which depend on A to become . A is also responsible for mobilising iron to incorporate it into the form of haemoglobin.

 

Deficiency conditions

 

Since A is required for maintaining and immunity, a deficiency can cause impaired vision and increased incidence of diseases in the body. is one of the foremost conditions caused by a deficiency of this . When the deficiency is less, it manifests itself as a slight change on conjunctive tissue of the eye. These are Bitot’s spots. In cases where the deficiency has reached more severe proportions, it can cause dryness of the eyes and finally result in on the , scarring and ultimately blindness in the person.

 

Children who have lower amounts of A in the blood tend to get more respiratory diseases as well as diarrhoea. Children who already have a condition of measles or diarrhoea as well as insufficient A tend to suffer more than children with a healthy level of A. In such children, the severity of the infection is more.

 

Deficiency Symptoms in Adults and Infants

 

A is responsible for the healthy growth of bones and tissues in children. Hence, a reduced level of this can result in retarding growth in a child. Therefore, the child could develop a growth defect and even dwarfism which is where the body parts fail to grow normally and assume a stunted appearance. Often the face will assume a mongoloid appearance and the facial bones will not develop fully resulting in a distorted facial appearance.

 

In adults as well as children, a deficiency of A can cause conditions like , inflammation in the eyes, inability to see properly at night, dryness of eyes, inflammation in the etc. In addition to conditions associated with the eyes, a person can experience roughness of the skin, dryness and increased presence of wrinkles. Children with insufficient A are more prone to as well as urinary tract infections. This can also manifest itself in adults who do not have sufficient A in their bodies.

 

Recommended daily amounts for each age group

 

The amounts of A needed depend on the person’s age group and gender. Women who are pregnant or breast-feeding need a higher concentration of A in their diets. Here is a break down of the recommended dosages of this :

 

·         Male and female infants aged below 6 months of age need 400 mg per day of A

·         Infants (both male and female) aged between 7 and 12 months need 500 mg per day

·         Children from 1 to 3 years of age need 300 mg of A each day

·         Children aged between 4 and 8 years require 400 mg A per day

·         Children aged from 9 to 13 years need 600 mg A each day

·         Teenagers aged from 14 to 18 years require 900 mg of A per day

·         Adults aged more than 19 years require 900 mg of A each day

·         Pregnant women who are aged below 18 years need 750 mg of A each day

·         Pregnant women aged above 19 years need 770 mg of A per day

Women who breast-feed and are aged below 18 years require 1200 mg in a day of A Women who breast-feed and are aged above 19 years require 1200 mg in a day of A

 

Top 10 Richest food sources

 

Most A sources reside in animal-based foods, such as poultry, beef etc. There are also a few plant sources, which contain this essential . Here is a list of these sources:

 

Beef liver: When cooked, 3 ounces of beef liver contain 27,185 IU of A Chicken liver: In cooked form, 3 ounces of chicken liver contain 12,325 IU of this Skimmed milk: One cup of skimmed and fortified milk contains 500 IU of A Cheddar cheese: One ounce of cheddar cheese contains 284 IU of A Egg substitutes: A quarter cup of egg substitutes contain 226 IU of A Carrots: Half a cup of carrots contains as much as 22,567 IU of A Spinach: A half cup of spinach boiled or frosen contains 11,458 IU of A Apricots: A half cup quantity of apricots with their skin intact contain around 2063 IU of A Peas: Half cup of boiled or frosen peas contains 1050 IU of A Oatmeal: Cooked with water, a cup of oats contains 1252 IU of A

 

When increased amounts may be needed

 

Consumption of too much alcohol can easily deplete the liver of its A levels. This can contribute to damaged liver functions. Moreover, the continued consumption of alcohol can contribute to more toxicity of the previously formed from A. Hence, even with additional A supplements the chances of improving the levels of this reduce in an alcoholic. Even contraceptives that have progestin and estrogens can reduce the levels of A in the body. These pills can result in increasing RBP production or binding proteins. However, it is not yet clear whether such a condition requires added intake of A by the body.

 

Any known interactions with other drugs (prescribed)

 

If a person is using any acitretin, retinoids or associated medications, isotretinoin, bexarotene or even etretinate then the person should not consume A supplements. These can increase toxic levels of A in the body.

 

 

 

 

Paul Leach

Webmaster of www.vitamins-australia.com.au

Powered by Yahoo! Answers