Hello everyone.
I am deeply intrigued by this vitamin A is a toxin thing going around and even more so by this clash of people being for and against.
I went to talk to ChatGPT to dig deeper.
Please do not try to discredit what I am about to post by saying "ChatGPT gives false information".
It certainly can give false information, but please read along and feel free to discredit something by addressing the particular thing in question and providing a good explanation why something is or is not so.
I wanted to know is Vitamin A essential or not:
So, from conversation with ChatGPT I made some observations:
Beta carotene is made by plants only. It is a starting point for all other forms of Vitamin A.
Herbivor animals obtain Vitamin A by consuming these plants and then converting beta carotene to other forms of Vitamin A. Retinol retinal and retinoic acid.
Carnivore animals by eating other animals which have eaten beta carotene containing plants and converted it to other forms of vitamin A storing it in tissues, primarily liver.
Beta carotene is a pigment molecule which is created through photo shynthesis. Plant uses it to further enhance processes involving light and energy creation for its own purposes or it is also used as a defense chemical to detere animals from eating the plant. Beta carotene is not directly toxic to animals, but its bright color discourages animals from eating the plant signaling other toxic chemicals.
In order to keep the post shorter I will write only about essentiality for vision:
Me:
tell more specifically how does it impair vision?
ChatGPT:
Vitamin A deficiency impairs vision primarily by affecting the functioning of the retina, the light-sensitive tissue at the back of the eye responsible for converting light into electrical signals that are sent to the brain for interpretation. Here's how vitamin A deficiency can impair vision:
1. **Rhodopsin Production**: Vitamin A is a key component in the synthesis of rhodopsin, a pigment found in the retina's rod cells. Rhodopsin is essential for low-light and night vision. In the absence of sufficient vitamin A, the synthesis of rhodopsin is compromised, leading to decreased sensitivity to low light levels.
Me:
how is rhodopsin synthesized?
ChatGPT:
Rhodopsin, the light-sensitive pigment found in the rod cells of the retina, is synthesized through a series of biochemical reactions involving vitamin A (retinol) and a protein called opsin. Here's an overview of the synthesis process:
1. **Absorption of Light**: The process of vision begins when light enters the eye and strikes the retina. Rod cells contain rhodopsin, which is composed of the protein opsin bound to a molecule of 11-cis-retinal (a form of vitamin A).
2. **Isomerization of 11-cis-Retinal**: When light hits the retina, it is absorbed by 11-cis-retinal, causing it to isomerize (change shape) into all-trans-retinal. This conversion triggers a conformational change in the opsin protein to which retinal is bound.
3. **Activation of Opsin**: The conformational change in opsin activates it, initiating a signaling cascade that ultimately leads to the generation of nerve impulses that are sent to the brain for visual processing.
4. **Signal Transmission**: The activated opsin interacts with other proteins in the rod cell membrane, ultimately leading to changes in ion flow across the cell membrane. This generates an electrical signal that is transmitted to the brain via the optic nerve.
5. **Regeneration of Rhodopsin**: After absorbing light and triggering a visual signal, the all-trans-retinal is released from opsin. It is then converted back to 11-cis-retinal through a series of enzymatic reactions in the retinal pigment epithelium (RPE) of the retina. This regenerated 11-cis-retinal can then recombine with opsin to form new rhodopsin molecules, allowing the process to repeat.
The synthesis and regeneration of rhodopsin are crucial for maintaining the sensitivity of rod cells to light and for the normal functioning of the visual system, especially in low-light conditions. The availability of vitamin A (retinol) is essential for the regeneration of 11-cis-retinal, highlighting the importance of adequate vitamin A intake for maintaining healthy vision.
Me:
so, if there wouldn't be any 11-cis-retinal, opsin protein would not receive a signal because there is nothing to absorb light and opsin cannot absorb light by itself?
ChatGPT:
That's correct. In the absence of 11-cis-retinal, the opsin protein alone cannot absorb light and initiate the signal transduction cascade required for vision. The binding of 11-cis-retinal to opsin is essential for the formation of the functional rhodopsin molecule, which serves as the light-sensitive pigment in rod cells. When light is absorbed by 11-cis-retinal, it triggers the isomerization of the retinal molecule and initiates the process of signal transduction that leads to the perception of light. Therefore, the presence of 11-cis-retinal is crucial for the normal functioning of the visual system.
Me:
how and from what is 11-cis-retinal made?
ChatGPT:
11-cis-retinal is derived from dietary sources of vitamin A. Here's a brief overview of its synthesis:
1. **Dietary intake:** Vitamin A is consumed through various dietary sources such as liver, eggs, dairy products, and certain fruits and vegetables.
2. **Absorption:** Vitamin A is absorbed from the intestines into the bloodstream.
3. **Transport:** In the bloodstream, vitamin A is transported primarily as retinol, bound to retinol-binding protein (RBP) and transthyretin (TTR).
4. **Conversion to retinal:** Retinol is converted to retinaldehyde (retinal) primarily in the liver. This conversion involves enzymes such as alcohol dehydrogenases and retinol dehydrogenases.
5. **Isomerization:** The trans-retinal produced from retinol undergoes isomerization to form 11-cis-retinal. This isomerization occurs in the retinal pigment epithelium (RPE) of the eye.
6. **Binding to opsin:** Once formed, 11-cis-retinal binds to the opsin protein present in the rod cells of the retina, forming the functional rhodopsin molecule.
The conversion of retinol to 11-cis-retinal is a crucial step in the visual cycle and is essential for normal vision. Any disruption in this process can lead to visual impairment and other related disorders.
So you can see from this that Vitamin A in fact is essential. If I have gotten something wrong here, please point it out. :)
Its toxicity comes from something else, maybe when it acumulates in excess.
Polar bears are know to have the highest content of Vitamin A in their livers. Why are they not bothered by this?
Maybe because they don't have an other toxins going around so they can deal with it.
Or, maybe if they would be able to avoid somehow getting so much vitamin A in their diet and accumulate it, maybe they would live longer and be even healthier.
One is true, and that is that vitamin A is essential. In which amount? I don't know.
I am deeply intrigued by this vitamin A is a toxin thing going around and even more so by this clash of people being for and against.
I went to talk to ChatGPT to dig deeper.
Please do not try to discredit what I am about to post by saying "ChatGPT gives false information".
It certainly can give false information, but please read along and feel free to discredit something by addressing the particular thing in question and providing a good explanation why something is or is not so.
I wanted to know is Vitamin A essential or not:
So, from conversation with ChatGPT I made some observations:
Beta carotene is made by plants only. It is a starting point for all other forms of Vitamin A.
Herbivor animals obtain Vitamin A by consuming these plants and then converting beta carotene to other forms of Vitamin A. Retinol retinal and retinoic acid.
Carnivore animals by eating other animals which have eaten beta carotene containing plants and converted it to other forms of vitamin A storing it in tissues, primarily liver.
Beta carotene is a pigment molecule which is created through photo shynthesis. Plant uses it to further enhance processes involving light and energy creation for its own purposes or it is also used as a defense chemical to detere animals from eating the plant. Beta carotene is not directly toxic to animals, but its bright color discourages animals from eating the plant signaling other toxic chemicals.
In order to keep the post shorter I will write only about essentiality for vision:
Me:
tell more specifically how does it impair vision?
ChatGPT:
Vitamin A deficiency impairs vision primarily by affecting the functioning of the retina, the light-sensitive tissue at the back of the eye responsible for converting light into electrical signals that are sent to the brain for interpretation. Here's how vitamin A deficiency can impair vision:
1. **Rhodopsin Production**: Vitamin A is a key component in the synthesis of rhodopsin, a pigment found in the retina's rod cells. Rhodopsin is essential for low-light and night vision. In the absence of sufficient vitamin A, the synthesis of rhodopsin is compromised, leading to decreased sensitivity to low light levels.
Me:
how is rhodopsin synthesized?
ChatGPT:
Rhodopsin, the light-sensitive pigment found in the rod cells of the retina, is synthesized through a series of biochemical reactions involving vitamin A (retinol) and a protein called opsin. Here's an overview of the synthesis process:
1. **Absorption of Light**: The process of vision begins when light enters the eye and strikes the retina. Rod cells contain rhodopsin, which is composed of the protein opsin bound to a molecule of 11-cis-retinal (a form of vitamin A).
2. **Isomerization of 11-cis-Retinal**: When light hits the retina, it is absorbed by 11-cis-retinal, causing it to isomerize (change shape) into all-trans-retinal. This conversion triggers a conformational change in the opsin protein to which retinal is bound.
3. **Activation of Opsin**: The conformational change in opsin activates it, initiating a signaling cascade that ultimately leads to the generation of nerve impulses that are sent to the brain for visual processing.
4. **Signal Transmission**: The activated opsin interacts with other proteins in the rod cell membrane, ultimately leading to changes in ion flow across the cell membrane. This generates an electrical signal that is transmitted to the brain via the optic nerve.
5. **Regeneration of Rhodopsin**: After absorbing light and triggering a visual signal, the all-trans-retinal is released from opsin. It is then converted back to 11-cis-retinal through a series of enzymatic reactions in the retinal pigment epithelium (RPE) of the retina. This regenerated 11-cis-retinal can then recombine with opsin to form new rhodopsin molecules, allowing the process to repeat.
The synthesis and regeneration of rhodopsin are crucial for maintaining the sensitivity of rod cells to light and for the normal functioning of the visual system, especially in low-light conditions. The availability of vitamin A (retinol) is essential for the regeneration of 11-cis-retinal, highlighting the importance of adequate vitamin A intake for maintaining healthy vision.
Me:
so, if there wouldn't be any 11-cis-retinal, opsin protein would not receive a signal because there is nothing to absorb light and opsin cannot absorb light by itself?
ChatGPT:
That's correct. In the absence of 11-cis-retinal, the opsin protein alone cannot absorb light and initiate the signal transduction cascade required for vision. The binding of 11-cis-retinal to opsin is essential for the formation of the functional rhodopsin molecule, which serves as the light-sensitive pigment in rod cells. When light is absorbed by 11-cis-retinal, it triggers the isomerization of the retinal molecule and initiates the process of signal transduction that leads to the perception of light. Therefore, the presence of 11-cis-retinal is crucial for the normal functioning of the visual system.
Me:
how and from what is 11-cis-retinal made?
ChatGPT:
11-cis-retinal is derived from dietary sources of vitamin A. Here's a brief overview of its synthesis:
1. **Dietary intake:** Vitamin A is consumed through various dietary sources such as liver, eggs, dairy products, and certain fruits and vegetables.
2. **Absorption:** Vitamin A is absorbed from the intestines into the bloodstream.
3. **Transport:** In the bloodstream, vitamin A is transported primarily as retinol, bound to retinol-binding protein (RBP) and transthyretin (TTR).
4. **Conversion to retinal:** Retinol is converted to retinaldehyde (retinal) primarily in the liver. This conversion involves enzymes such as alcohol dehydrogenases and retinol dehydrogenases.
5. **Isomerization:** The trans-retinal produced from retinol undergoes isomerization to form 11-cis-retinal. This isomerization occurs in the retinal pigment epithelium (RPE) of the eye.
6. **Binding to opsin:** Once formed, 11-cis-retinal binds to the opsin protein present in the rod cells of the retina, forming the functional rhodopsin molecule.
The conversion of retinol to 11-cis-retinal is a crucial step in the visual cycle and is essential for normal vision. Any disruption in this process can lead to visual impairment and other related disorders.
So you can see from this that Vitamin A in fact is essential. If I have gotten something wrong here, please point it out. :)
Its toxicity comes from something else, maybe when it acumulates in excess.
Polar bears are know to have the highest content of Vitamin A in their livers. Why are they not bothered by this?
Maybe because they don't have an other toxins going around so they can deal with it.
Or, maybe if they would be able to avoid somehow getting so much vitamin A in their diet and accumulate it, maybe they would live longer and be even healthier.
One is true, and that is that vitamin A is essential. In which amount? I don't know.