Vitamin A - Retinol, was discovered in 1916. But only 15 years later its chemical structure was determined. And it took another 15 years before we learned to produce it synthetically (in the form of acetate). It's quite rare in dietary supplement stores, which is odd because a lack of it can lead to even gray-blindness.
Vitamin A is necessary for the production of rhodopsin, a visual pigment that we use in low light conditions. A deficiency of this vitamin causes poor vision in low light conditions, and a severe deficiency can lead to night blindness. First, you may notice that you have trouble driving or reading in the evening, and later you may lose your vision completely in low light. Night blindness can also be hereditary, even if it is treated with vitamin A.
The recommended daily dose is 0.8 mg or 4.8 mg of betacarotene (the ratio is 1:6). Vitamin A is therefore produced by the human body itself, it must be consumed. Good sources are carrots, yellow and green leafy vegetables, spinach, cabbage, parsley, watermelon, broccoli, corn, butter, egg yolk... From flesh food it is fish oil and liver.
It is also possible to overdose on vitamin A (hypervitaminosis) because it is stored in the baking. It can cause osteoporosis and poisoning. It is known to be present in large quantities in the baking of Arctic animals (dogs, wolves, bears), which has led to the poisoning of some polar expeditions that ran out of food supplies and had to hunt or even eat sled dogs.
Vitamin deficiency causes (in addition to the aforementioned night blindness) skin flaking, decreased sexual activity, slowed sexual development, decreased potency, decreased immunity, and a tendency toward inflammation. It is therefore important to determine whether we are deficient in this vitamin (see its deficiency - weaker vision, skin problems...) and make the most appropriate dietary changes, or take direct supplements in the form of vitamin capsules.
Vitamin A is often used in cosmetics, in lipsticks and balms applied to the face, because of its supposed skin rejuvenation (labeled as Retinol). This form of intake can be dangerous and experts warn against it, especially if you are a post-menopausal woman. The opposite extreme is a poor country with a lack of healthy, where the absence of vitamin A altogether often leads to blindness!
With vitamin A more than elsewhere - everything in moderation! Therefore, a healthy, balanced diet is essential. If you suspect, or are already directly deficient, it is definitely better to supplement it through a certified nutritional supplement, where you can precisely dose it and perfectly distribute your intake over the days.
