The human body contains practically the entire Mendeleev’s table. Without it, the body cannot live and will not feel well and even get sick when some elements are missing. However, we will also feel unwell if we have too many of them.
Vitamin A is one of the most important players in all chemical reactions. It is known as the ‘vision vitamin’ but it has many other roles. Let’s discover together the different properties of this nutrient and its positive and possible negative effects on the way our body works.
Key functions – good stuff
Vitamin A or (Retinol – vitamin A active form or retinoic acid) is essential for many processes in the body, including maintaining healthy vision, ensuring proper functioning of the immune system and organs, and for the proper growth and development of the baby in the mother’s womb.
Vitamin A is an important fat-soluble vitamin. A fat-soluble vitamin is one that the body can store within the fat cells, holding onto it for when it’s needed.
1Protects the eyes from night blindness and age-related degeneration
Vitamin A is essential for the preservation of sight. It is necessary for converting light into an electrical signal that can be transmitted to the brain. In fact, one of the first symptoms of vitamin A deficiency can be night blindness, known as nyctalopia.
Night blindness occurs in people with vitamin A deficiency, as this vitamin is the main component of rhodopsin pigment. Rhodopsin is found in the retina and is extremely sensitive to light. People with this condition can see normally during the day, but their vision is reduced in the dark because their eyes have difficulty capturing light at low levels.
2Maintains a healthy immune system
Vitamin A plays a vital role in maintaining the body’s natural defences. This includes the mucous barriers of the eyes, lungs, intestines and genitals, which help to trap bacteria and other infectious agents. It is also involved in the production and functioning of white blood cells, which help to capture and cleanse the blood of bacteria and other pathogens. This means that vitamin A deficiency can increase your susceptibility to infections and delay recovery when you get sick.
3Essential for lungs
Human lung development begins in the fifth foetal week and continues throughout the first few years of life. The foetal lung develops postnatally to become one of the most complex organs, characterized by approximately 40 different cell types. The primary function of the lung is to meet the organism’s need for oxygen and CO2 removal.
Vitamin A is stored in hepatic stellate cells in the liver but also in other organs. These cells, which have been also detected in the lungs including the foetal lung, can take up retinol from chylomicron.
The concentration of total vitamin A in human lungs between 4 months and 86 years of age ranges from 8.7-1102.2 nmol/g. The maternal supply of vitamin A is essential for the adequate supply, growth and development of the foetus. Vitamin A, associated with the formation of retinoic acid, is important for the regulation of early lung development and alveolar formation. Consequently, adequate intake should be ensured during the last month of pregnancy, providing the retinol stores in the developing lung required for retinoic acid synthesis during lung maturation and in postnatal life.
4Helps reduce child mortality
An analysis of 6 studies demonstrated clinically and statistically significant reductions in all-cause mortality in children aged 6 months to 5 years. In 5 (of 6) of the Asian trials, the level of impact was remarkably similar: a 29-54% reduction in mortality. Most of the prevented deaths were related to measles and diarrhoeal disease, not because the incidence of measles or diarrhoeal disease decreased, but because the clinical manifestations among those who received vitamin A supplements were less severe.
5Promotes healthy growth and fertility
Vitamin A is essential for maintaining a healthy reproductive system in men and women as well as for ensuring the normal growth and development of embryos during pregnancy.
In pregnant women, vitamin A is also involved in the growth and development of many of the baby’s major organs and structures, including the skeleton, nervous system, heart, kidneys, eyes, lungs and pancreas.
However, an excess of vitamin A during pregnancy can also harm the growing baby and lead to birth defects. High doses of vitamin A have a powerful teratogenic effect and are therefore contraindicated during pregnancy.
6Reduces the risk of skin acne
Vitamin A plays an important role in the health of the skin and may be helpful in managing acne. One of the key functions of vitamin A is to support the growth and development of skin cells, as well as to regulate the production of sebum, the oil that can clog pores and contribute to acne.
Retinoids, which are derivatives of vitamin A, are often used topically or orally to treat acne. These compounds work by decreasing the production of sebum and promoting the turnover of skin cells, which can help to prevent the formation of new acne lesions and improve the appearance of existing ones. Although acne is harmless, it can affect a person’s mental health and lead to low self-esteem, anxiety and depression. According to a study published in October 2016, 19.2% of adolescents with acne have suffered in their personal and social lives, and sociophobia was present in 45% of patients with acne.
Vitamin A belongs to the group of fat-soluble vitamins. Fat-soluble vitamins are normally stored in the liver and can accumulate in the body over time if consumed in excess.
Bad news if you are deficient in vitamin A
Vitamin A is an important nutrient that plays a role in many essential body functions. Deficiency can occur when a person does not get enough vitamin A to meet the body’s needs which can lead to alarming symptoms.
Initially, the eyes can become very dry, which can cause damage to the cornea and retina. Night blindness can also result from vitamin A deficiency. This results in a person not seeing or not seeing well in low light, eventually leading to total blindness at night.
Vitamin A plays a key role in immune function. A person with a vitamin A deficiency may experience more frequent infections as they cannot fight off these infections as easily.
The effect of chronic vitamin A deficiency is increased severity and mortality risk of infections (particularly measles and infection-associated diarrhoea). In 2013, 94,500 children in low-income and middle-income countries died of diarrhoea and 11,200 died of measles as a result of vitamin A deficiency. More than 95% of deaths attributable to vitamin A deficiency occurred in sub-Saharan Africa and Asia.
Some people with vitamin A deficiency may notice skin problems such as dryness, itching and flaking. Some people may experience similar problems with their hair and scalp.
Vitamin A plays an important role in reproduction, and its deficiency can cause infertility and difficulty in conceiving a child.
Bad news if over-consumed or overloaded
Overconsumption of vitamin A can lead to toxic levels as excessive amounts can be stored in the body.
Hypervitaminosis of vitamin A is caused by consuming too much vitamin A in animal-based foods or supplements containing the vitamin. Symptoms may include nausea, dizziness, headaches, pain and even death.
But eating large amounts of provitamin A carotenoids, such as beta-carotene, found in plant foods does not сarry the same risk and can be converted into active vitamin A (retinol) in the body as needed.
How much vitamin A do we need? Norms and recommendations
The total vitamin A content of a food is usually expressed as micrograms (µg) of retinol equivalents (RE).
The recommended daily intake of Vitamin A is set by the Food and Nutrition Board (FNB) of the Institute of Medicine (IOM), which is part of the National Academies of Sciences, Engineering, and Medicine in the United States.
Best ways to get vitamin A
The best way to get vitamin A is through a varied and balanced diet, which includes a range of foods high in vitamin A. Animal products and some vegetables are particularly good sources of vitamin A.
Most cost-efficient ways
Vitamin A, like all vitamins and minerals, should be taken from food. This is the first priority. It is better to avoid supplements and vitamin A is no exception. Foods rich in vitamin A are the best source of it. It is tasty and varied and you can make lots of delicious dishes from it to please yourself. You would agree that vitamin A supplements are unable to cope with this task.
So regular consumption of food rich in vitamin A is an excellent choice. You will not be deficient in this vitamin and you will enjoy a number of benefits.
But if you choose not to follow our advice and take a vitamin A supplement, you should check the appropriate dosage with your doctor first, and also take into account that you still consume some vitamin A in your diet.
What processes reduce the effect of vitamin A
There are several factors that can reduce the amount of vitamin A in food:
Heat. Vitamin A is sensitive to heat, and it can be destroyed or reduced if foods are cooked at high temperatures for long periods of time.
Light. Vitamin A is also sensitive to light, so exposure of foods to light may cause damage to the vitamin.
Air. Oxygen can also cause the destruction of vitamin A, so storing food in an airtight container will help maintain vitamin A content.
Water. Some vitamin A in food can be lost if it is washed or soaked in water.
Processing. Certain food processing methods, such as canning and freezing, can also reduce the vitamin A content of foods.
Ageing. The vitamin A content of foods can also decrease over time, especially if they are not stored properly.
Curious facts & stories
Elmer V. McCollum, an American biochemist known for his work on the influence of diet on health and Marguerite Davis an American biochemist and co-discoverer of vitamin A, studied the composition of egg yolk and butter back in 1913, in which they found a lipoid substance responsible for growth in mammals. In 1914, scientists had already clearly demonstrated that butter also contained an unknown substance that was insoluble in water and unbreakable by alkalis. This unknown substance was designated as ‘fat-soluble factor A.’ In 1916 this substance was given its modern name – vitamin A.
Let’s sum up
Vitamin A is essential for many important processes in your body. It is used to support healthy vision, normal organ function and the immune system, and to ensure babies’ normal growth and development in the womb. We have to consume it regularly with different food rich in this vitamin. It is the best and the most cost-efficient way. Also, it is worth noting that both too little and too much vitamin A can have a negative impact on your health.
Not enough? Here are some more
In this video, Dr. Berg tells you about the sources of vitamin A, its functions and its deficiencies. Dr Berg is a chiropractor who specializes in healthy ketosis & intermittent fasting. He is the author of the best-selling book ‘The Healthy Keto Plan’ and is the director of Dr. Berg Nutritionals. Let’s watch!
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