Vitamin A, also known as Retinol, is a fat-soluble vitamin that has considerable important functions in human body.
Vitamin A: History
References to Vitamin A deficiency and its treatment can be found in many places throughout history. However, in 1913, scientists announced it as a fat-soluble vitamin. It is a nutrient essential for growth and survival. Two groups of scientists were researching it that year. At the University of Wisconsin, E. V. McCullum and Marguerite Davies were one group and a group of T. B. Osborne and L. B. Mandel were working in Yale University. They separately demonstrated that a component of butter was essential for the physiological growth of rats. In 1930 T. Moore, a scientist, made an important discovery. A pigment called carotene is present in carrots and some other fruits. Vitamin A was found in their livers when given to mice deficient in vitamin A. Carotene is a yellow substance found in vegetables. It is converted into vitamin A in the body.
Vitamin A: Functions in Body
maintains eyes and vision
prevents eye diseases
essential for body growth
essential for reproduction and general health
increases immunity in chest and other disorders
helps keep the integument or lining of the eyes, lungs, stomach and intestines intact
aids in the digestion of proteins by aiding the digestive juices in the stomach
avoids skin diseases
hair, teeth and gums remain healthy
increases the permeability of micro blood vessels
helps to supply more oxygen to each cell
avoids premature and sudden old age, alternatively, youth lasts longer
Sources of Carotene
Carotene is a fat-soluble precursor of vitamin A that exists in green and yellow vegetables. A small portion of carotene is absorbed from the intestines and contributes to the yellow serum color. The major sources of Carotene are:
eggs, milk, butter
Vitamin A: Deficiency Symptoms
Prolonged lack of vitamin A causes:.
loss of appetite
lack of enthusiasm
inner skin of the nose, throat, mouth, trachea, intestines, kidneys and vagina of women get affected.
bubble lining becomes rough
these organs deteriorate quickly
30,000 mcg daily intake of Vitamin A for a few months shows the toxic effects of vitamin A. Avoid giving 5550 mcg daily intake of Vitamin A to infants.
Symptoms of toxic effects are:
Hair loss, nausea, vomiting, diarrhea, scaly skin, blurred vision, bone pain, irregular periods, fatigue, headache, liver swelling. If a large dose is taken at once, symptoms such as stomach cramps, nausea, vomiting, dizziness, fatigue etc. are seen.
12000 daily intake of Vitamin A several may cause symptoms such as leg pain, joint pain, hair loss, chapped lips, anal fissures, loss of appetite, fever and weight loss.