Vitamin A deficiency is a surprisingly major health problem worldwide. It is most prevalent in children and expectant women. It is the world leading cause of preventable blindness in children. It compromises immunity and increases the risk of disease and death from severe infections. It is a significant contributor to maternal and child mortality.

According to the World Health Organisation, an estimated 250 million preschool children are Vitamin A deficient and it is likely that in Vitamin A-deficient areas a substantial proportion of pregnant women are Vitamin A-deficient. An estimated 250.000 to 500.000 Vitamin A-deficient children become blind every year, half of them dying within 12 months of losing their sight

For children, lack of Vitamin A causes severe visual impairment and blindness, and significantly increases the risk of severe illness, and even death, from such common childhood infections as diarrhoeal disease and measles.

For pregnant women in high-risk areas, Vitamin A deficiency occurs especially during the last trimester when demand by both the unborn child and the mother is highest. The mother's deficiency is demonstrated by the high prevalence of night blindness during this period. The impact of Vitamin A deficiency on mother-to-child HIV transmission needs further investigation

Overall, it is crucial for a healthy immune system.

Normally, the liver stores 80 to 90% of the body's Vitamin A so anything that destroys it (like alcohol abuse) can lead to Vitamin A deficiency.

Night blindness: This is the earliest symptom of Vitamin A deficiency. It is the result of difficulty for the eyes to adjust to dim light. Affected individuals are unable to distinguish images in low levels of illumination. People with night blindness have poor vision in dim light or/darkness, but see normally when adequate light is present.

Vitamin A is needed for the production of rhodopsin, the eye pigment responsible for sensing low light situations. Without this pigment, the eye cannot see well in dim light.

Xeropthalmia: This is a condition where eyes fail to produce tears. Prolonged deficiency results in drying of the conjunctiva (the mucous membrane that lines the inner surface of the eyelids and extends over the forepart of the eyeball). With continued Vitamin A deficiency, the drying extends to the cornea. The cornea eventually shrivels up and becomes ulcerated (keratomalacia). Superficial, foamy gray triangular spots may appear in the white of the eye (Bitot's spots). Finally, inflammation and infection occur in the interior of the eye, resulting in total and irreversible blindness.

Changes in the skin and the mucous membranes in the respiratory, GI, and urinary tracts can occur. Drying, scaling, and follicular thickening of the skin and respiratory infections can result. Immunity is generally impaired. This results in respiratory, urinary and other infections.

The younger the patient, the more severe are the effects of Vitamin A deficiency. Growth retardation and infections are common among children. Mortality rate can exceed 50% in children with severe Vitamin A deficiency.

If you have any of these eye symptoms, go to your doctor who will check your retinol (Vitamin A) levels and institute the necessary management.

Remember a Vitamin A deficiency in lactating mothers will produce breast milk with low levels of Vitamin A. Maternal supplementation benefits both mother and breast-fed infant: high dose Vitamin A supplementation of the breast-feeding mother in the first month after delivery 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.

The treatment for Vitamin A Deficiency related problems involves giving high dose Vitamin A (usually available as retinyl palmitate) either orally or through injection.

In children with complicated measles, Vitamin A can shorten the duration of the disorder and reduce the severity of symptoms and risk of death.

The prognosis for correcting night blindness is excellent.

Xerophthalamia can be corrected with Vitamin A therapy. Ulcerations, tissue death, and total blindness, caused by severe Vitamin A deficiency, cannot be treated with Vitamin A.