Hello and welcome to the start of the, in depth, series about all 13 essential vitamins.
In this series I´m going to explain:
- a special characteristic of the vitamin
- what the specific vitamin is
- what the demand is
- where you can get it (Top 5 foods)
- what the functions and benefits are
- what deficiency symptoms exist
- what overdose symptoms exist
- what else you may have to consider
So today, in part 1, we are going to start with the first letter of the alphabet, the importance of Vitamin A.
Why can you call vitamin A, the visionary?
You may all have heard about it. Eat enough foods with vitamin A, e.g. carrots, and you will see like an eagle. Actually, this is not just a saying, it is true because vitamin A is involved in the production of rhodopsin, a pigment, which let´s us perceive light. And this is the requirement to see our environment. Without the perception of light, everything is dark and black.
So vitamin A gives us the possibility to see our visions, that what is inside of us, on the outside.
What is Vitamin A?
There are several fat-soluble, chemical compounds, which are summarized as vitamin A. These include retinol (reference value, animal), retinal (carotenoids, provitamin A (e.g. beta carotene) and derivatives also found in animals), retinoic acids (undergroup of retinoids, which are related to retinol) and retinyl palmitate/retinyl ester (animal). And there are some more compounds or derivatives, also synthetical ones.
Seems too complicated. Just keep in mind, that there is vitamin A in animals (mostly retinyl palmitate/retinyl ester and retinol) and in plants as natural colorings (mostly retinal as a carotenoid, including provitamin A).
What is the demand of Vitamin A?
Depending on the age, health and lifestyle the daily demand for an average and healthy adult for the essential vitamin A
is 700 – 1000 micrograms (μg) per day.
Where can you get Vitamin A from (Top 5 foods)?
As mentioned above there are two major sources of vitamin A through nutrition. Plant and animal foods.
The amount of the vitamin in a food depends on several factors. Is it raw or cooked? In which environment has it been grown? And some more.
Here are the Top 5 foods, which are rich in vitamin A:
1. Liver (>>1000 μg/100g; up to 50.000 μg/100g)
2. Carrots (up to 1300 μg/100g)
3. Sweet potatoes (up to 1000 μg/100g)
4. Pumpkin (up to 800 μg/100g)
5. Cale (up to 800 μg/100g)
Now we know why rabbits like carrots so much. It helps them to see their environment better.
Tip: Eat foods rich in vitamin A with a little bit of fat, so vitamin A can be absorbed better in your body.
Notice: Although liver is rich in vitamin A and other vitamins and minerals like vitamin B complex, vitamin D, iron and copper, it is recommended to eat it seldom (max. once a month). Personally, I don´t want to eat it at all. This is not only advisable due to a possible vitamin A hypervitaminosis, but also due to possible heavy metals and other toxic degradation products. If you like liver, prefer to choose calf liver, as heavy metals and toxins accumulate over the age of the animal.
What are the functions and benefits of Vitamin A?
Vitamin A is important for a proper function of the immune system and the metabolism, the production of the reproductive cells and as mentioned above for the visual process. Moreover, it is responsible for the development of the skin, the mucous membranes, the blood and bone cells.
What deficiency symptoms of Vitamin A exist?
A hypovitaminosis of vitamin A is seldom and can cause the followed symptoms:
- infections and flu-like infections
- decreased visual acuity
- dry skin, mucous membrane. hair, nails and eyes
- night blindness
- decreased fertility
- growth and blood formation disorders
- disorders in the smell and sense of touch
What overdose symptoms of Vitamin A exist?
A hypervitaminosis of vitamin A can cause the followed symptoms:
- gastrointestinal complaints
- unwanted bone growths
- yellow skin (beta carotene)
- unwanted liver growths or liver intoxication
Fact: Did you know that the inuit don´t eat polar bear or seals liver because it contains so high amounts of vitamin A, that you can die of a vitamin A poisoning?
Fun Fact: Do you ever wanted to have yellow skin? Then take enough beta carotene. More than 30 mg of it per day makes your skin yellow. Up to 300 mg per day is Ok for a healthy person (not smokers and drinkers), as it does not cause the symptoms of a hypervitaminosis. It will be formed to vitamin A only on demand.
What else may you have to consider about Vitamin A?
There are several preforms of vitamin A in foods, such as provitamin A (e.g. beta carotene), retinyl palmitate/retinyl ester and retinol.
Provitamin A can be converted to vitamin A, but you will need six times more of it compared to retinol. Retinyl palmitate/retinyl ester is a preform of retinol. Retinol can be oxidated to retinal, which can be oxidated to retinoic acids.
The vitamin A metabolism is dependent on retinol binding proteins, which are enzymes binding free vitamin A, as retinol, retinal/ provitamin A and retinoic acids.
50 – 80 % of the storaged vitamin A is in our liver.
Retinol, which was discovered in 1913, is extremely fashionable in skin creams, as it has the ability to smooth the skin. Your body is also able to resorb vitamin A over your skin.
The word carotene is originated from the Latin word “carota”, which belongs to the natural pigments found in colored roots, fruits and leafs.
So be sure to take your amount of vitamin A. One big carrot a day with some fat ((pro)vitamin A is fat-soluble) is enough. Observe your amount of liver consumption, as high quantities can lead to a vitamin A overdose. A hypovitaminosis is seldom as vitamin A is a storage vitamin.
What do you think now? Was something new or interesting here for you? Let us know in the comments.