The role of vitamin A in the immune system — the missing link between vaccine reactions and autoimmune disease?
A possible key to understanding autoimmune diseases and physiological balance
Background: Grant Generaux argues in his book Extinguishing the Fires of Hell that the Western world is suffering from vitamin A toxicity, and that this explains the rise in autoimmune diseases. Genraux is correct in pointing out that there is a connection between vitamin A, the immune system, and the symptoms that could explain these autoimmune conditions. Reading the book it is easy to believe that an excess of the vitamin might be the culprit, even I started doubting. This theory has spread widely, encouraging people to avoid highly nutritious organ meats like liver and to severely restrict their vitamin A intake.
However, Generaux’s theory fails on one crucial point. He states that retinol accumulates in the liver over time (which is true) and claims that we cannot eliminate it — except for a small amount naturally each day which is why the liver retinol levels eventually become overloaded and toxic . This is where he is wrong. Retinol plays a key role during infectious diseases, when the liver actually releases its retinol stores to help fight various infections. This means that an intake to rebuild these reserves is essential.
Here, his entire theory of widespread toxicity collapses — and I would argue that it is, in fact, deficiency that deserves more attention. And i will prove why in this article ———
During the course of the pandemic, vitamin D has received a boost in both research and the media, often linked to its immunomodulatory functions. But in parallel, there is a quieter, teammate who has figured in the shadow of it – vitamin A, or rather its bioactive metabolites called retinoids. These appear to play a deeply integrated role in immune system regulation, inflammation response, and viral defense. Despite this, they have largely been avoided, or forgotten in the public discourse. There is also an emerging theory suggesting that vitamin A should be completely avoided due to its potential for liver accumulation and toxicity, and its alleged link to autoimmune diseases — a theory I intend to challenge and disprove here. A growing number of studies now suggest that imbalances in retinoid metabolism – both overload and functional deficiency – may be a common denominator in several modern conditions: from severe COVID-19 and autoimmune diseases, to vaccine-related reactions and chronic inflammation and autoimmune diseases.
Retinoids in the machinery of the immune system
Retinoids (vitamin A) regulate the expression of hundreds of genes linked to immune response. They are particularly important for:
Maturation of T cells (especially regulatory T cells)
Synthesis of type I interferon – the body's first line against viruses
Integrity of mucous membranes and barrier functions Down-regulation of exaggerated inflammatory responses
Several clinical studies have shown that patients with severe COVID-19 have markedly lowered levels of retinol, sometimes so low that they resemble classic vitamin A deficiency. Retinol Depletion in COVID-19 https://pmc.ncbi.nlm.nih.gov/articles/PMC9142171/
Studies also show that patients with mild infection can suffer from rapidly declining retinol levels during immune stress. This suggests that the body consumes vitamin A reserves at a rapid rate in case of infection. A novel hypothesis for COVID-19 pathogenesis: Retinol depletion and retinoid signaling disorder https://www.sciencedirect.com/science/article/pii/S0898656821002102?.COM
Retinoic acid binds to SARS-CoV-2
The research has also shown that retinoic acid can bind directly to the spike protein of SARS-CoV-2 and stabilize it in a less infectious configuration. This supports the idea that retinoids not only regulate the body's defenses, but they can directly inhibit the functioning of the virus. A Retinol Derivative Inhibits SARS-CoV-2 Infection by Interrupting Spike-Mediated Cellular Entry https://pubmed.ncbi.nlm.nih.gov/35862773/
Twofold pathology: toxic overload → functional deficiency
Recent research points to a two-way mechanism: Immune activation (through infection or vaccination) triggers a strong release of retinyl esters from the liver – the body's vitamin A stores – which temporarily creates retinoid overabundance in the blood. This causes a toxic effect on cells (so-called endogenous hypervitaminosis A), followed by depletion of stores, which causes retinoid deficiency just when the body needs vitamin A the most.
Phase 1 — Acute release (excess):
When the immune system is strongly activated (such as by multiple vaccinations or infection), the liver releases large amounts of retinyl esters (storage form of vitamin A) into the bloodstream.
This leads to a temporary excess of retinoids in circulation (endogenous hypervitaminosis A).
This excess can be toxic to cells, potentially causing neuroinflammation and other adverse effects.
Phase 2 — Depletion (deficiency):
After this surge, the liver stores become depleted, leading to a relative deficiency of vitamin A exactly when the body needs it for immune repair and regulation.
This deficiency phase may impair tissue repair and immune function, exacerbating susceptibility to further damage.
Mawson A.M., Croft A.M. (2020). Multiple Vaccinations and the Enigma of Vaccine Injury. https://pubmed.ncbi.nlm.nih.gov/33198395/
This raises questions about the risks of mass vaccination in recent years, but also about the scheduled childhood vaccines we so routinely give our children. Since the symptoms of vitamin A deficiency are consistent with neurological autoimmune diseases and the fact that retinoids have been shown to be necessary to regulate receptors and mechanisms in the hippocampus - the question is whether we have an elephant in the room here?
"The distribution of retinoid receptor proteins in the adult nervous system is different from that seen during development. and suggests that retinoid signaling likely has a physiological role in the adult cortex, amygdala, hypothalamus, hippocampus, striatum, and associated brain regions. A number of neuronal specific genes contain recognition sequences for the retinoid receptor proteins and can be regulated directly by retinoids. Disruption of retinoid signaling pathways in rodent models indicates their involvement in the regulation of synaptic plasticity and associated learning and memory behaviors. Retinoid signaling pathways have also been implicated in the pathophysiology of Alzheimer's disease, schizophrenia, and depression. "
Role of retinoid signalling in the adult brain https://pubmed.ncbi.nlm.nih.gov/15882777/
This raises a very important question: Do multiple vaccines and infections distrupt the retonic acid signaling system leading to an imbalance - hypervitaminosis A and eventually retinol deficiency?
A 2018 study determined that vitamin A supplements reduce symptoms in autistic children. The article's introduction reproduces the results of their previous research in 2016, where 77.9% of autistic children showed vitamin A deficiency, which constituted the highest deficiency rate among the nutrients studied (including vitamin D, vitamin B₁₂ and folic acid), and where the concentration of vitamin A was negatively associated with CARS scores. Vitamin A improves the symptoms of autism spectrum disorders and decreases 5-hydroxytryptamine (5-HT): A pilot study https://www.sciencedirect.com/science/article/abs/pii/S0361923017303404
Vitamin D took the spotlight – but we forgot about A
During the COVID-19 pandemic, vitamin D quickly became a subject of debate and research. Hundreds of studies have since examined its immune-regulating effects, its impact on viral progression, and the link between vitamin D deficiency and severe disease. But at the same time, vitamin A – whose role is just as fundamental – has been overlooked. A recent study points out the importance of balance between vitamins A and D in maintaining physiological homeostasis:
"Thus, a balance of vitamin A and D is essential for maintaining physiological homeostasis both molecularly and cellularly."
The study suggests that an imbalance between these two fat-soluble vitamins can lead to dysregulation of immunity, oxidation, and gene expression. In other words: The positive effects of vitamin D can be undermined if vitamin A is out of phase – and vice versa. Vitamin A and vitamin D induced nuclear hormone receptor activation and its impact on B cell differentiation and immunoglobulin production https://www.sciencedirect.com/science/article/abs/pii/S0165247823001591?via%3Dihub
It's also worth noting that both vitamin A (in the form of retinoic acid) and vitamin D (as calcitriol) act as hormone-like molecules that act by binding to nuclear receptors — RAR/RXR for vitamin A and VDR (Vitamin D receptor) for vitamin D — and regulate gene expression, cell growth, immune function, and inflammation — a fact that leads many researchers to question whether they should be classified as "vitamins" in the traditional sense at all. (Ramanarayanan et al., 2023) https://pubmed.ncbi.nlm.nih.gov/37774987/
A key component of post-infectious and autoimmune conditions?
In postviral syndromes and certain autoimmune diseases, patients often have signs of both inflammation and liver stress. This has previously been explained by autoimmunity or residual infection – but I suggest that it may be (or at the same time) a dysfunction in vitamin A metabolism because of a distrupted retonic acid signaling system that drives the condition. Which is why it is reasonable to ask:
Could some long-term symptoms after infection or vaccination be due to chronically low retinoid signaling and distrupted regulatory systems?
Should we measure retinol and RBP4 levels more frequently in clinic?
How does diet, liver function, and previous immune activation affect our vitamin A stores – especially in children?
This becomes a very important reflection in the context of changing dietary habits in the Western world. Organ meats – especially liver – and also cod liver oil, which has historically been a rich source of natural vitamin A and used both traditionally and therapeutically, have been largely replaced by modern, processed foods with a low nutrient density. At the same time, the natural fat intake has been reduced (a good source of retinol), and replaced with seed oils, which also affects the absorption of fat-soluble vitamins such as A and D. This may have contributed to the body's retinol reserves being more vulnerable in the face of immunological stress – which in turn raises a wider question: Can changes in dietary habits and the gradual depletion of fat-soluble vitamins and specifically vitamin A, through vaccinations and repeated infections, be an underlying factor in the increasing incidence of autoimmune diseases in the Western world? And are the vaccines partly to blame?
Especially when studies show that the intake of retinol from the conversion of beta-carotene from vegetables such as carrots is not sufficiently bioavailable compared to direct intake from animal sources:
"The vitamin A activity of beta-carotene, even when measured under controlled conditions, can be surprisingly low and variable." Variability in conversion of beta-carotene to vitamin A in men as measured by using a double-tracer study design https://pubmed.ncbi.nlm.nih.gov/11976165/
Conclusion: Have we forgotten the importance of vitamin A?
An increasingly clear picture is now emerging that vitamin A's role in immune regulation is both profound and unexplored – especially in the context of disease, infection, inflammation and vaccination. And that the western population are potentially depleted of the important retinol. Of course, there is also the risk of overload, especially in infancy and childhood when the liver is not fully developed. Which demonstrates the importance of balance and healthy intake of a diet with a high retinol content. But that does not overshadow the evidence that the West is rather suffering from shortages. It is also important to understand that signs of overload seem to be the same diffuse autoimmune symptoms.
Where vitamin D has taken its place as an immune booster in the aftermath of the pandemic, vitamin A has remained hidden. However, its effect seems to be more than a supplement, rather a necessary co-regulating factor for the proper functioning of the immune system.
To ignore vitamin A – both as an overload and as a deficiency – is to overlook a potential key to several modern disease processes. And I think it's time to take this "elephant in the room" seriously.