According to the World Health Organization, vitamin A deficiency is a public health problem that particularly affects young children and pregnant women in low-income countries. In this article, we will present the main symptoms and causes of vitamin A deficiency as well as its sources and tips.
Lack of vitamin A is a public health problem
Vitamin A is the generic name for a group of organic compounds that comprises retinol, retinoic acid, retinaldehyde and pro-vitamin A carotenoids.
It is a very important nutrient for our organism, which contributes to good vision as well as growth and development, integrity of epithelial cells, gene expression, reproduction, immune system and antioxidant defense.
Estimates indicate that 250 million preschool children in the world have vitamin A deficiency, and that 25, 00 to 50, 00 children become blind every year, with half of them dying within 12 months of the loss of view.
Another group suffering from lack of vitamin A are pregnant women. In high-risk settings, this deficiency tends to occur in the last trimester of pregnancy, when demand for the vitamin increases (for both mother and fetus).
Vitamin A deficiency is a public health problem in the African continent, Southeast Asia and in the states of Amazonas, Bahia, Ceará, Minas Gerais, Paraíba, Pernambuco, Rio de Janeiro and São Paulo.
One of the most well-known symptoms of vitamin A deficiency is night blindness, a condition that leaves a person unable to distinguish images when illumination is poor. It is worth mentioning that the problem arises when the shortage is already serious. Keratomalacia, a disease characterized by desiccation, xerosis and corneal ulcer and conjunctivitis, usually precedes nocturnal blindness.
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Lack of vitamin A can also lead to keratinization of the skin (follicular hyperkeratosis) and mucous membranes of the digestive tract, urinary tract and respiratory tract (which reduces their efficacy infections.)
Other symptoms observed in the deficiency of vitamin A are the reduction of the amount of osteoclasts (cells responsible for the resorption of the bone tissue, which leads to increased deposition in the periosteum), the occurrence of anemia (by the vitamin acting on iron metabolism), depression of the immune system, problems in spermatogenesis, abnormal embryonic development and abortion.
In children, in addition to eye diseases, vitamin A deficiency is related to severity of common childhood illnesses, such as pneumonia, measles and diarrhea, and may even lead to the death. When it comes to pregnant women, lack of vitamin A also causes night blindness and may increase the risk of maternal mortality.
As causes of lack of vitamin A, we can mention:
- The low intake of foods that are sources of this nutrient, by following restrictive diets or economic issues (poverty);
- Low fat content in the diet (vitamin A is fat soluble and needs fat to be absorbed);
- Alcoholism, which is associated with a lack of various nutrients (the alcoholic stops eating to drink);
- The lack of zinc, because the mineral is involved in the transport of vitamin A (the lack of zinc decreases the synthesis of and the transformation of retinol into retinal (the enzyme retinol dehydrogenase is dependent on zinc);
- Diseases that compromise intestinal absorption (celiac disease, Chron's disease);
- Diseases that compromise the absorption of fats (pancreatitis, cystic fibrosis, biliary obstruction);
- Do not breastfeed or introduce food early (breastmilk contains optimal amounts of vitamin A);
- The occurrence of frequent infections in children (which reduce appetite and increase vitamin A needs).
Sources of vitamin A
In animal foods, the main form of vitamin A is retinyl esters, such as retinol palmitate, which is converted to retinol in the small intestine. In vegetables, the carotenoids are found.
As an example of good sources of vitamin A we can mention sweet potatoes, carrots, spinach, cabbage, chard, turnip, broccoli, tomato, papaya, eggs, shrimp, salmon, sardines, tuna, etc.
- To know other sources of vitamin A, it is enough to be guided by the color: vegetables of orange, red or dark green coloration contain good amounts of this nutrient;
- Studies have shown a higher content of lycopene (carotenoid) in the blood after eating cooked tomatoes than when fresh. Prefer, therefore, consume them in the form of sauce. Note: Other factors may have contributed to this greater availability, such as the crushing of tomato cells, which in itself facilitates digestion. This shows the importance of chewing food for the use of its nutrients;
- Baking also helps to release more carotenoids from the carrot;
- Remember to use some type of oil, such as olive oil, in the preparation of food (to aid absorption of vitamin A).
Ordinance No. 2160/94 of the Ministry of Health created the Program for the Control of Vitamin A Deficiency which has as one of its objectives to eliminate "vitamin A deficiency as a public health problem in risk areas in Brazil" and ensure "the supplementation with massive doses of vitamin A in children from 6 to 59 months of age, living in an area at risk".
It is worth mentioning that vitamin A supplementation should always be done according to medical advice. Excess consumption of any vitamin also causes health damage.
Have you ever felt symptoms of lack of vitamin A in your body? Do you believe that you can increase your intake of your main sources during the day to day? Comment below!(4votes, average:, 0of 5)