How Does Our Body Respond to Vitamin A Deficiency?

Vitamin A deficiency is very common in developing countries where people lack access to Vitamin A-rich foods.

The World Health Organization estimates that approximately 250,000 to 500,000 undernourished children in third world countries become blind every year due to Vitamin A deficiency. In the United States, Vitamin A deficiency is rare. When it occurs, it is usually associated with severe dietary restrictions and extreme intake of alcohol. Zinc deficiency is often seen alongside Vitamin A deficiency. Zinc is required to create the binding proteins that transport Vitamin A through our bodies. Zinc deficiency limits our body's ability to transport stores of Vitamin A from the liver to the tissues.

One of the first signs of Vitamin A deficiency is night blindness. Vitamin A deficiency contributes to blindness by drying up the cornea of the eye and simultaneously damaging both the retina and the cornea. Vitamin A deficiency also inhibits the body's capacity to fight infections. Many children die from Vitamin A deficiency as they live in countries where immunization is limited. Their deaths are often caused by infectious diseases like measles and pneumonia. If a person is Vitamin A-deficient, the cells lining his lungs lose their capacity to eliminate disease-causing bacteria. This often leads to pneumonia.

The following groups of Americans are most at risk of Vitamin A deficiency:

Toddlers and preschool-aged children
Children living below the poverty line
Children with no access to healthcare or immunization programs
Children living in areas known for nutritional deficiencies
Immigrants or refugees that have arrived in America recently from third world countries, where there are high rates of Vitamin A deficiency or measles
Children with diseases of the pancreas, liver or bowels
Children with inadequate fat digestion or absorption