Vitamin A Deficiency
Vitamin A is one of the most vital nutrients requisite for a healthy human body. Vitamin A is essential for eye health and proper functioning of the immune system. It is found in foods such as milk, liver, eggs, red and orange fruits, red palm oil and green leafy vegetables, although the amount of vitamin A readily available to the body from these sources varies widely.
Deficiency and its causes
Vitamin A deficiency sets in when the body contains lesser than the minimum amount of essential vitamin A. Vitamin A deficiency usually results from inadequate intake of foods high in vitamin A (liver, kidney, butter, milk, cream, cheese, and fortified margarine) or carotene, a precursor of vitamin A found in dark green leafy vegetables and yellow or orange fruits and vegetables. (Six mg of beta-carotene is equal to 1 mg of vitamin A.) The recommended daily allowance for vitamin A is 1 mg for adult males and 0.8 mg for adult females.
In addition to dietary problems, there are other causes of vitamin A deficiency. Iron deficiency can affect vitamin A uptake. Excess alcohol consumption can deplete vitamin A, and a stressed liver may be more susceptible to vitamin A toxicity.
Effects of deficiency
- Vitamin A deficiency can lead to blindness
- Vitamin A deficiency diminishes the ability to fight infections
- Even mild, subclinical deficiency can also be a problem, as it may increase children’s risk of developing respiratory and diarrheal infections, decrease growth rate, slow bone development, and decrease likelihood of survival from serious illness.
- Abnormal function of many epithelial cells, manifest by such diverse conditions as dry, scaly skin, inadequate secretion from mucosal surfaces, infertility, decreased synthesis of thyroid hormones and elevated cerebrospinal fluid pressure due to inadequate absorption in meninges.