The major cause of Vitamin A Deficiency is diets which comprehend few animal sources of preformed vitamin A. Breast milk of a lactating mother with vitamin A deficiency contains petite vitamin A, which provides a breast-fed child with too little vitamin A.
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.
People who consume large amounts of alcohol should seek medical advice before taking vitamin A supplements. In general, people should also seek medical advice before taking vitamin A supplements if they have any condition associated with fat mal-absorption such as pancreatitis, cystic fibrosis & biliary obstruction.
Vitamin A deficiency also diminishes the ability to fight infections. In countries where children are not immunized, infectious disease like measles have relatively higher fatality rates. As elucidated by Dr. Alfred Sommer, 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.
Vitamin A deficiency is common in developing countries but rarely seen in developed countries. Night blindness is one of the first signs of vitamin A deficiency. Complete blindness can also occur due to retinal injury – Vitamin A has a major role in phototransduction. Approximately 250,000 to 500,000 malnourished children in the developing world go blind each year from a deficiency of vitamin A, approximately half of which die within a year of becoming blind.
The United Nations Special Session on Children in 2002 set the elimination of vitamin A deficiency by 2010. The prevalence of night blindness due to vitamin A deficiency is also high among pregnant women in many developing countries. Vitamin A deficiency also contributes to maternal mortality and other poor outcomes in pregnancy and lactation.
Treatment.
As an oral form, the supplementation of vitamin A is effective for lowering the risk of morbidity, especially from severe diarrhea, and reducing mortality from measles and all-cause mortality. Some countries where vitamin A deficiency is a public health problem address its elimination by including vitamin A supplements available in capsule form with National Immunization Days (NIDs) for polio eradication or measles.
Vitamin A capsules cost about US$ 0. 02. The capsules are easy to handle; they don’t entail to be stored in a refrigerator or vaccine carrier. When the correct dosage is given, vitamin A is safe and has no negative effect on seroconversion rates for Oral Polio Vaccine or measles vaccine. However, because the benefit of vitamin A supplements is transient, children need them regularly every four to six months.
Since NIDs provide only one dose per year, NIDs-linked vitamin A distribution must be complemented by other dose programs to maintain vitamin A in children Maternal high supplementation benefits both mother and breast-fed infant: high dose vitamin A supplementation of the lactating mother in the first month postpartum can provide the breast-fed infant with an appropriate amount of vitamin A through breast milk.
However, high-dose supplementation of pregnant women should be avoided because it can cause miscarriage and birth defects.
Treatment of vitamin A deficiency can be undertaken with both oral and injectable forms, generally as vitamin A palmitate.