Information About Vitamin a

Vitamin A

Introduction

Often touted as a miracle vitamin, vitamin A is the secret to great skin, higher immunity levels and holistic growth. Vitamin A is a powerful antioxidant that also improves eyesight, helps strengthen bones, protects the body from heart related diseases, alleviates acne and psoriasis conditions, reduces wrinkles, alleviates respiratory ailments and helps improve measles and glaucoma conditions.

Functions within the body

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

Deficiency conditions

Since vitamin A is required for maintaining eyesight and immunity, a deficiency can cause impaired vision and increased incidence of diseases in the body. Night blindness is one of the foremost conditions caused by a deficiency of this vitamin. 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 ulcers on the cornea, scarring and ultimately blindness in the person.

Children who have lower amounts of vitamin 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 vitamin A tend to suffer more than children with a healthy level of vitamin A. In such children, the severity of the infection is more.

Deficiency Symptoms in Adults and Infants

Vitamin A is responsible for the healthy growth of bones and tissues in children. Hence, a reduced level of this vitamin 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 vitamin A can cause conditions like night blindness, inflammation in the eyes, inability to see properly at night, dryness of eyes, inflammation in the cornea 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 vitamin A are more prone to respiratory ailments as well as urinary tract infections. This can also manifest itself in adults who do not have sufficient vitamin A in their bodies.

Recommended daily amounts for each age group

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

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

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

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

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

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

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

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

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

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

Top 10 Richest food sources

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

• Beef liver: When cooked, 3 ounces of beef liver contain 27,185 IU of vitamin A

• Chicken liver: In cooked form, 3 ounces of chicken liver contain 12,325 IU of this vitamin

• Skimmed milk: One cup of skimmed and fortified milk contains 500 IU of vitamin A

• Cheddar cheese: One ounce of cheddar cheese contains 284 IU of vitamin A

• Egg substitutes: A quarter cup of egg substitutes contain 226 IU of vitamin A

• Carrots: Half a cup of carrots contains as much as 22,567 IU of vitamin A

• Spinach: A half cup of spinach boiled or frosen contains 11,458 IU of vitamin A

• Apricots: A half cup quantity of apricots with their skin intact contain around 2063 IU of vitamin A

• Peas: Half cup of boiled or frosen peas contains 1050 IU of vitamin A

• Oatmeal: Cooked with water, a cup of oats contains 1252 IU of vitamin A

When increased amounts may be needed

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