Supplementing high doses of vitamin A for children is an effective measure to help prevent the consequences of vitamin A deficiency. So what role does vitamin A play in the body? Which foods contain vitamin A? At what age do children need high doses of vitamin A? The answer will be in this article.

Vitamin A is a group of important micronutrients widely present in the human diet, playing a major role in the normal functioning of many physiological functions. Vitamin A deficiency can cause serious consequences, even death. So when is it necessary to supplement high doses of vitamin A for children? Let’s find out through the article below.

What role does vitamin A play in the body?

Vitamin A is an essential component of many biological functions, including embryonic development and has important effects on postnatal physiological events such as cell differentiation and proliferation, immunity, vision and reproduction, and is also an important antioxidant.

Vision

The retina is the structure responsible for visual perception, including the transmission of signals to the brain. Vitamin A derivatives bind to the protein opsin (a protein receptor in the retina) to form rhodopsin, a pigment important for light perception. A deficiency of retinol leads to impaired vision in low light conditions due to the lack of rhodopsin formation, a condition that causes night blindness.

Vitamin A helps maintain good vision in the dark

Cancer

Several studies have demonstrated the potential protective effects of vitamin A against certain cancers such as lymphoma and lung, liver, and ovarian tumors. Vitamin A is used in the treatment of acute myelogenous leukemia, promoting cell differentiation by activating transcription factors. In addition, carotenoids have been studied to inhibit the generation of reactive oxygen species, induce apoptosis in tumor cells, and prevent cancer development.

Immunity

Vitamin A acts as a cofactor in the proliferation and differentiation of T cells into regulatory T cells (important mediators for preventing regulatory autoimmune reactions), several immune functions through indirect processes and modulation of hematopoietic stem cell dormancy, and other inflammatory mediators. Vitamin A deficiency leads to imbalances in the immune system and impairs the immune response to infections such as measles and parasitic infections.

Vitamin A deficiency impairs immune response to infections

Skin diseases

Vitamin A aids in the daily turnover of skin cells and ensures that tissues such as the conjunctiva can produce mucus and provide a barrier against infection. Vitamin A is commonly used in skin diseases such as psoriasis, photodamage, seborrhea, acne, etc. Among them:

• Isotretinoin is often recommended for acne because it acts as a topical bactericide, reduces inflammation and regenerates sebaceous glands.
• Acitretin is a derivative of vitamin A, effective in psoriasis, discoid lupus due to its anti-inflammatory and anti-proliferative effects.

According to the World Health Organization (WHO), vitamin A deficiency is a public health problem in 50% of countries; it is the most common nutritional disorder in the world, along with protein malnutrition. The leading cause of vitamin A deficiency in humans is poor diet, which occurs particularly in poor and developing countries and can be exacerbated by high rates of infection, especially diarrhoea and measles.

Vitamin A sources

Vitamin A is an essential micronutrient that comes in several forms, including retinol, retinal and retinoic acid. It can be found in the following sources:

• Animal sources: Liver, eggs, dairy products and fatty fish;
• Plant sources: Vitamin A exists as provitamin A carotenoids, mainly beta carotene – the only substance that is converted into usable vitamin A by the body, found in dark-coloured fruits and vegetables such as leafy greens, carrots, ripe mangoes, bell peppers and other yellow-orange fruits and vegetables.

Fat-soluble vitamin A, which is required in our diet, is absorbed as retinol from retinoids or as carotenoids that are metabolized to retinal, which can then be converted to retinol in the intestinal cells. They are then transported to the liver for storage via chylomicrons and then released into the circulation and to the tissues where they are biologically active bound to retinol-binding proteins. The absorption of vitamin A from animal sources appears to be considerably higher and more significant than that of carotenoids from plants. However, due to their hydrophobic nature, the absorption of both vitamin A sources depends on the solubility of the micelles and therefore on the fat content of the diet.

Vitamin A can be found in animals and plants.

At what age do children need high-dose vitamin A supplementation?

Vitamin A is a nutrient that the human body cannot synthesize and therefore must be obtained from dietary sources. High-dose oral vitamin A supplementation and food fortification are the most direct methods of providing vitamin A to people with deficient diets. Stages of life that require high-dose vitamin A supplementation for children include:

Pregnant women

Pregnancy is a period of special nutritional needs to maintain the health of both mother and fetus. During this period, the need for vitamin A increases, especially in the last 3 months due to the rapid growth of the fetus during this period. During pregnancy, circulating retinoids in the mother (retinol and retinyl esters) provide vitamin A to the fetus and must be transported across the placental barrier. Vitamin A deficiency during embryogenesis and the first months of life is associated with organ malformations, manifested by cardiovascular and nervous system deficiencies and poor tissue development, premature birth, and low vitamin A stores in newborns, increasing the risk of infectious diseases and potentially having negative effects on later health. Inadequate maternal vitamin A intake during pregnancy not only leads to inadequate vitamin A supply to the fetus but also affects the infant during lactation through breast milk.

Vitamin A is essential for fetal development.

Breastfeeding women

During lactation, breastfeeding mothers are susceptible to vitamin A deficiency because the infant absorbs vitamin A from maternal stores. Vitamin A is one of the most important micronutrients in infancy, affecting lung function and maturation, making it susceptible to infection.

Pregnant and lactating women are considered to be at high risk due to their increased micronutrient requirements and should be advised to consume nutrient-rich products containing β-carotene or, even better, vitamin A plus β-carotene, to avoid nutritional deficiencies.

Infants

The World Health Organization recommends high-dose vitamin A supplementation every 6 months for children aged 6 to 59 months to reduce child morbidity and mortality. High-dose vitamin A supplementation in children during this time has been shown to reduce the risk of malnutrition, diarrhea, acute respiratory infections, and mortality from many causes.

High-dose vitamin A supplementation every six months for children 6 to 59 months of age

In summary, vitamin A is necessary for normal functioning of the visual system, maintaining cell function for growth, epithelial integrity, red blood cell production, immunity and reproduction. During the fetal stage, children from 6 to 59 months of age are the time when high doses of vitamin A are needed for children. Vitamin A deficiency during these stages increases the risk of a number of problems in children. However, it is necessary to consult a doctor to supplement vitamin A properly, because using large amounts of vitamin A for a long time can lead to poisoning.