The Vitamin Deficiency Linked To Long COVID

Long COVID is more likely to be seen in those who have lower levels of this hormone.

Long COVID is more likely to be seen in those who have lower levels of this hormone.

Patients with low levels of vitamin D who had recovered from coronavirus are at greater risk of developing long COVID.

Post-COVID syndrome, also known as long COVID is a condition that affects some people after the initial illness.

These patients may experience health problems and wide-ranging symptoms that could last for more than 3 months.

Several studies suggest that the condition affects between 50 to 70 percent of hospitalised COVID-19 patients.

Some of these patients experience severe symptoms leading to intubation and mechanical ventilation.

Vitamin D deficiency has been suggested as a risk factor, but its impact on long COVID has not been checked before.

The study measured vitamin D levels in patients with COVID-19 at the beginning of their admission and 6 months after leaving hospital.

The results showed that patients with long COVID had lower levels of 25(OH) vitamin D than those who had fully recovered.

Lower 25(OH) vitamin D levels was observed more frequently in those patients with neurocognitive symptoms such as brain fog, confusion, poor concentration, and forgetfulness.

Professor Andrea Giustina, the study’s lead author, said:

“Previous studies on the role of vitamin D in long COVID were not conclusive mainly due to many confounding factors.

The highly-controlled nature of our study helps us better understand the role of vitamin D deficiency in long COVID, and establish that there is likely a link between vitamin D deficiency and long COVID.”

The next step for the research team is to find out whether vitamin D supplements can lower the odds of post COVID-19 syndrome.

Professor Giustina said:

“Our study shows that COVID-19 patients with low vitamin D levels are more likely to develop long COVID but it is not yet known whether vitamin D supplements could improve the symptoms or reduce this risk altogether.”


The study was published in The Journal of Clinical Endocrinology & Metabolism (Filippo et al., 2023).

Long COVID: This Severe Neurological Symptom Is Highly Selective

This long COVID symptom is in addition to difficulties with smell, taste, memory and speech.

This long COVID symptom is in addition to difficulties with smell, taste, memory and speech.

COVID-19 can cause difficulties recognising people’s faces as well as with navigation, a study finds.

This can be added to the other commonly experienced neurological symptoms of so-called ‘long COVID’, the main three being brain fog, headaches and numbness.

Some people also continue to suffer difficulties with smell, taste, memory, speech and even psychosis after suffering from COVID.

Long COVID is when the symptoms from the novel coronavirus infection last longer than six weeks.

Face blind

Researchers worked with a woman called Annie who suffered from long COVID and was having problems with navigation and face recognition.

She was unable to recognise members of her only family by their faces alone and was having problems navigating to places that were extremely familiar to her.

Professor Brad Duchaine, study co-author, said:

“The combination of prosopagnosia [face blindness] and navigational deficits that Annie had is something that caught our attention because the two deficits often go hand in hand after somebody either has had brain damage or developmental deficits.

That co-occurrence is probably due to the two abilities depending on neighboring brain regions in the temporal lobe.”

A series of tests on Annie found she had great difficulty both with recognising well-known faces and in discriminating between learned faces and new ones.

Ms Marie-Luise Kieseler, the study’s first author, said:

“Our results from the test with unfamiliar faces show that it wasn’t just that Annie couldn’t recall the name or biographical information of a famous person that she was familiar with, but she really has trouble learning new identities.”

However, she had no difficulties with other related abilities, such as recognising voices.

Professor Duchaine said:

“It’s been known that there are broad cognitive problems that can be caused by COVID-19, but here we’re seeing severe and highly selective problems in Annie, and that suggests there might be a lot of other people who have quite severe and selective deficits following COVID.”

Cognitive deficits after COVID

To explore if these deficits might be widespread, the researchers surveyed over 50 people who had had long COVID and compared them with those who had had COVID but had fully recovered.

Ms Kieseler explained the results:

“Most respondents with long COVID reported that their cognitive and perceptual abilities had decreased since they had COVID, which was not surprising, but what was really fascinating was how many respondents reported deficits.

It was not just a small concentration of really impaired cases but a broad majority of people in the long COVID group reported noticeable difficulties doing things that they were able to do before contracting COVID-19 without any problems.”

Professor Duchaine said:

“One of the challenges that many respondents reported was a difficulty with visualizing family and friends, which is something that we often hear from prosopagnosics.”


The study was published in the journal Cortex (Kieseler & Duchaine, 2023).

This Vitamin Helps Fight COVID Pneumonia

A vitamin that makes the lung lining stronger against respiratory infection and prevents COVID-19.

A vitamin that makes the lung lining stronger against respiratory infection and prevents COVID-19.

Vitamin D can help combat respiratory infections including COVID-19, pneumonia and influenza, a study reveals.

Several clinical trials have suggested that individuals with vitamin D deficiency are 5 times more likely to experience severe COVID-19 infection, hospitalization, and death.

Some studies have also found a strong association between higher serum levels of vitamin D and reduced likelihood of infection.

This study takes these further, providing evidence that higher vitamin D supplementation could help preventing respiratory infections.

The researchers observed that treatment with 50 nmol/L calcitriol, an active form of vitamin D, enhanced airway barrier function.

Calcitriol makes the lung lining stronger, reducing fluid leaks and lowering the inflammatory response to cell injury from bacteria, viruses, or toxic compounds.

This means the vitamin helps fend off viral or bacterial infections responsible for respiratory illnesses such as COVID pneumonia.

Professor James Mullin, the study’s senior author, said:

“Your body is mostly sacs and tubes.

If their linings are in good shape, you’re in good shape.

If they’re leaking and fail to provide a proper barrier, it’s a problem.

When you have a respiratory infection, that means the barrier in your lungs is leaking.

Our research gives evidence that vitamin D strengthens the barrier function of the lung lining, likely helping to prevent or stop an infection.”

For this study, the human lung tissue samples were examined.

They noticed that treatment with 50 nM calcitriol for 48 hours greatly improved barrier function of bronchial epithelial cells and decreased proinflammatory responses.

This indicates the potential effects of vitamin D supplementation on preventing cytokine storms in COVID-19 patients.

The inflammation caused by COVID-19 is known as a ‘cytokine storm’.

The ‘storm’ is an overaction of the immune system to try and kill the virus.

Professor Mullin said:

“The benefits, however, are so clear and the risks so minimal that we believe physicians should be recommending supplemental vitamin D right away.

Cytokine storms, where the body’s immune response kicks into overdrive and can result in severe disease and death in COVID, compromise the body’s airway barrier function.

We already know from past studies that vitamin D blunts cytokine storms in cases of flu.

In cases of COVID-19, vitamin D therapy may allow time for a patient’s own immune defenses to kick in before it’s too late.”

According to one study, adequate levels of 25-hydroxyvitamin D (30 nanogram per millilitre) protect patients with COVID-19 against complications and death, as well as reducing the risk of getting ill by a large amount.

The study was published in Physiological Reports (Rybakovsky et al., 2023).

Long COVID: Most Common Symptoms & Time To Recovery

How long it takes to return to normal after mild COVID-19 infection.

How long it takes to return to normal after mild COVID-19 infection.

While most people do not experience long-term illness after infection, some however suffer from long COVID.

According to a study, patients with mild COVID-19 will recover from lingering symptoms and return to normal life within one year.

Long COVID is a long-term health condition occurring after recovery from the initial infection with on and off symptoms such as dyspnea (shortness of breath), loss of smell, loss of taste, poor concentration, and fatigue.

Breathing difficulties

Breathing problems appear to be the most common symptom of long COVID which affects more unvaccinated people than vaccinated ones.

Since the coronavirus pandemic, the long COVID phenomenon has caused lots of anxiety and even fear in the population.

However, the research shows that the majority of patients with mild COVID infection will recover quickly showing no signs of serious illness or long term health conditions.

For instance, the number of long COVID patients in the UK is estimated at about 1.5 million, which is equivalent to 2.4 percent of the population.

Long COVID symptoms study

To analyse the outcomes of long COVID illness, researchers compared the health status of patients who had recovered from prolonged symptoms one year after infection with uninfected people.

They checked the medical data of 2.5 million Israelis and compared vaccinated patients with unvaccinated people with or without COVID infection.

Those seriously ill from coronavirus and patients with prior health conditions were excluded.

Other factors such as smoking, alcohol intake, and socioeconomic status were also taken into consideration as they could potentially influence the results.

During early and late periods of COVID-19 infection, patients were more likely to suffer from conditions such as breathing difficulties, dizziness, fatigue, loss of smell and taste, palpitations, poor concentration, and sore throat.

Patients were more likely to experience respiratory disorders, muscle aches, chest pain, hair loss, and cough during the early period of coronavirus disease.

People who had mild COVID-19 were nearly 5 times more likely to experience loss of smell and taste during the early phase and 3 times more likely in the late period.

Fatigue, shortness of breath, and sore throat were the most probable symptoms in patients with long COVID.

Vaccinated people who got sick with COVID-19 were less likely to experience breathing difficulty than unvaccinated patients but the risk of developing all other symptoms was similar in both groups.

The authors write that:

“Our study suggests that mild COVID-19 patients are at risk for a small number of health outcomes and most of them are resolved within a year from diagnosis.

Importantly, the risk for lingering dyspnea was reduced in vaccinated patients with breakthrough infection compared with unvaccinated people, while risks of all other outcomes were comparable.”

The study was published in The BMJ (Mizrahi et al., 2023).

A Vitamin Deficiency That Doubles COVID Hospitalisation Risk

Low levels of this vitamin is linked to a higher risk of COVID-19 infection and and hospitalisation.

Low levels of this vitamin is linked to a higher risk of COVID-19 infection and and hospitalisation.

The risk of contracting COVID-19 may be reduced by sufficient levels of vitamin D, research finds.

A large Israeli population-based study found a significant link between low blood levels of vitamin D and COVID-19 infection.

Low plasma 25(OH) vitamin D levels in COVID patients seem to be an independent risk factor for infection and hospitalisation.

Dr Eugene Merzon, the study’s first author, said:

“The main finding of our study was the significant association of low plasma vitamin D level with the likelihood of COVID-19 infection among patients who were tested for COVID-19, even after adjustment for age, gender, socio-economic status and chronic, mental and physical disorders.”

A blood level of 30 nanogram per millilitre 25(OH) vitamin D and higher has been shown to protect patients with COVID-19 against complications and death, as well as reducing the risk of getting ill.

Sufficient levels of vitamin D could halve the risk of catching coronavirus and save COVID-19 patients from the worst of the disease.

25-hydroxyvitamin D is produced in the liver and it is a major form of vitamin D3 and vitamin D2.

Past studies have suggested that low status of vitamin D increases the likelihood of respiratory tract infections.

Vitamin D is crucial for immediate immune response through adjusting white blood cell reactions and reducing their production of cytokines.

Dr Ilan Green, study co-author, said:

“Our finding is in agreement with the results of previous studies in the field.

Reduced risk of acute respiratory tract infection following vitamin D supplementation has been reported.”

Milana Frenkel-Morgenstern, study co-author, said:

“According to our analysis, persons that were COVID-19 positive were older than non-infected persons.

Interestingly, the two-peak distributions for age groups were demonstrated to confer increased risk for COVID-19: around ages 25 and 50 years old.

The first peak may be explained by high social gathering habits at the young age.

The peak at age 50 years may be explained by continued social habits, in conjunction with various chronic diseases.”

Data analysis across 20 countries in Europe suggests that a large number of COVID-19 cases and high death rates could be related to vitamin D deficiency.

Besides being important for the immune system, vitamin D is a key factor in many physiological processes such as bone growth and calcium absorption.

Vitamin D deficiency has been related to cognitive decline, autoimmune conditions, type 2 diabetes, cardiovascular diseases, and obesity.

A study points out that vitamin D is a seasonal vitamin and so emphasises the need for vitamin D intake in winter.

Exposure to the sun for even 15 minutes daily can give the body a chance to make enough vitamin D.

Vitamin D is found in foods such as oily fish including salmon, trout, mackerel, and sardines, eggs, liver, and some fortified foods including diary.

The study was published in The FEBS Journal (Merzon et al., 2020).

Long COVID Starves Brain Of Oxygen & Triggers ‘Brain Fog’ (M)

Long COVID is when the symptoms from the novel coronavirus infection last longer than six weeks.

Long COVID is when the symptoms from the novel coronavirus infection last longer than six weeks.

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Long COVID: 4 Neurological Symptoms Experienced By 85%

Long COVID is when the symptoms from the novel coronavirus infection last longer than six weeks.

Long COVID is when the symptoms from the novel coronavirus infection last longer than six weeks.

Brain fog, headache and numbness are three of the most common neurological symptoms of long COVID, research finds.

Long COVID is when the symptoms from the novel coronavirus infection last longer than six weeks.

The majority of patients recover within four to six weeks.

The research found that 85 percent of people who experienced long COVID had at least four neurological symptoms.

These strongly impacted their quality of life and, for some people, impaired their thinking skills.

The study included 100 people from the U.S. who had had COVID but the disease had not, apparently, been severe.

Dr Igor Koralnik, study co-author, said:

“Our study is the first to report neurologic findings in non-hospitalized COVID-19 long-haulers, including detailed neurologic exam, diagnostic testing, and validated measures of patient quality of life, as well as cognitive function test results.

All patients in this study had clinical symptoms consistent with COVID-19, but only had mild and transient respiratory symptoms (sore throat, cough, mild fever) and never developed pneumonia or low oxygen levels requiring hospitalization.”

The results of the study showed that the most frequent neurological symptoms of long COVID were:

  • Brain fog (81 percent)
  • Headache (68 percent)
  • Numbness/tingling (60 percent)
  • Disorder of taste (59 percent)
  • Disorder of smell (55 percent)
  • Muscle pain (55 percent)
  • Dizziness (47 percent)
  • Pain (43 percent)
  • Blurred vision (30 percent)
  • Tinnitus (29 percent)

The non-neurological symptoms included:

  • Fatigue (85 percent)
  • Depression/anxiety (47 percent)
  • Shortness of breath (46 percent)
  • Chest pain (37 percent)
  • Insomnia (33 percent)

Dr Koralnik said:

“We were surprised by the number of patients who were suffering from depression/anxiety before their COVID-19 diagnosis, and this suggests a possible neuropsychiatric vulnerability to developing long COVID.”

People with long-COVID may be finding it hard to get treatment, Dr Koralnik said:

“This may have been caused by the difficulty for these patients to find medical providers, since they do not fit into classical diagnostic criteria of COVID-19.

This is reminiscent of the stigma experienced by women with fibromyalgia and chronic fatigue syndrome, highlighting the need for improved diagnostic ‘gold standards’ for COVID-19 infection, which our group hopes to address by elucidating the T cell response of long-haulers against COVID-19 proteins.”

The study was published in the journal Annals of Clinical and Translational Neurology (Graham et al., 2021).

The Reason COVID-19 Causes Fatigue And Brain Fog

The inflammation caused by COVID-19 is known as a ‘cytokine storm’.

The inflammation caused by COVID-19 is known as a ‘cytokine storm’.

The COVID-19 virus enters the brain, research finds.

The study could help explain why people with COVID-19 are reporting cognitive symptoms like brain fog and fatigue.

Professor William A. Banks, study co-author, said:

“We know that when you have the COVID infection you have trouble breathing and that’s because there’s infection in your lung, but an additional explanation is that the virus enters the respiratory centers of the brain and causes problems there as well.”

The research on mice found that the virus was able to enter the brain.

After being injected in the body, the so-called ‘spike protein’ of the virus ended up in 12 regions of the brain.

The spike protein usually detaches from the virus and wreaks the same havoc in the body as the virus itself.

The spike protein was transported more quickly in male mice, which may explain the particular susceptibility of men to the virus.

Professor Banks said:

“The S1 protein likely causes the brain to release cytokines and inflammatory products.”

The inflammation caused by COVID-19 is known as a ‘cytokine storm’.

The ‘storm’ is an overaction of the immune system to try and kill the virus.

In the process, the infected person experiences brain fog, fatigue and other cognitive issues, along with the main symptoms of the virus.

Professor Banks said:

“You do not want to mess with this virus.

Many of the effects that the COVID virus has could be accentuated or perpetuated or even caused by virus getting in the brain and those effects could last for a very long time.”

The spike protein functions in a similar way to a critical HIV protein called gp 120.

Both function as ‘arms’ for the virus, helping it to grab on to receptors.

Both gp 120 and the COVID spike protein are likely toxic to brain tissue.

The study was published in the journal Nature Neuroscience (Rhea et al., 2020).

Long COVID: The Top 2 Neuropsychiatric Symptoms

A quarter of people with long COVID met the criteria for depression.

A quarter of people with long COVID met the criteria for depression.

Headaches and fatigue are the top neuropsychiatric symptoms of so-called ‘long COVID’, research finds.

These were the two most common symptoms reported over four months after people had had COVID, with 69 percent reporting fatigue and 67 reporting headaches.

Next most common were:

  • changes to taste (54 percent) and smell (55 percent),
  • mild cognitive impairment (47 percent),
  • 30 percent had problems with memory,
  • and 20 percent report confusion.

Other physical symptoms of long COVID include:

  • cough,
  • muscle aches,
  • nasal congestion,
  • and chills.

Perhaps unsurprisingly, 25 percent also met the criteria for depression.

Dr Elizabeth Rutkowski, study co-author, said:

“There are a lot of symptoms that we did not know early on in the pandemic what to make of them, but now it’s clear there is a long COVID syndrome and that a lot of people are affected.”

Long COVID study

The results come from 200 patients who were recruited around four months after becoming infected with COVID.

The numbers suffering some effects of long COVID may be higher, as some people did not notice the changes in themselves.

Dr Rutkowski explained that taste strips were used to check people’s sense of taste, but it may be that the sense of taste has changed, rather than having totally gone:

“They eat a chicken sandwich and it tastes like smoke or candles or some weird other thing but our taste strips are trying to depict specific tastes like salty and sweet.”

Long COVID and fatigue

Fatigue is likely such a common symptom of long COVID because the infection raises levels of inflammation in the body — and these levels remain raised.

Dr Rutkowski said:

“They have body fatigue where they feel short of breath, they go to get the dishes done and they are feeling palpitations, they immediately have to sit down and they feel muscle soreness like they just ran a mile or more.

There is probably some degree of neurologic fatigue as well because patients also have brain fog, they say it hurts to think, to read even a single email and that their brain is just wiped out.”

Cognitive problems, including lack of vocabulary, may also reflect the long spells people have spent in isolation.

Dr Rutkowski said:

“You are not doing what you would normally do, like hanging out with your friends, the things that bring most people joy.

On top of that, you may be dealing with physical ailments, lost friends and family members and loss of your job.”

ACE2 receptors

COVID is thought to have such widespread effects on the human body because the virus attaches itself to angiotensin-converting enzyme-2, or ACE2.

ACE2 regulates many different bodily functions including inflammation and blood pressure.

ACE2 is found throughout the body: in the brain, heart, lungs kidneys and gastrointestinal tract.

The ACE2 receptor is on the surface of cells and acts like a doorway to allow the virus inside.


The study was published in the journal  Brain, Behavior, & Immunity (Chen et al., 2022).

How Long After Infection Omicron Symptoms Start To Show Up

How fast the omicron variant spreads among people, including fully vaccinated young adults.

How fast the omicron variant spreads among people, including fully vaccinated young adults.

Omicron is highly transmissible and is the most dominant COVID-19 strain at this time due to how quickly it can spread.

For most cases, it takes 3 days from exposure to the Omicron variant to see the symptoms.

Also, in some individuals the symptoms can show up on the first day of infection or up to 8 days afterwards.

The findings come from a Norwegian study that looked at an Omicron outbreak following a Christmas dinner party.

The collected information was based on 111 participants who had attended that party which was held in Oslo on 26 November 2021.

Attendees were between the age of 30 and 50 and fully vaccinated or had previously had COVID.

They had also tested negative after taking a PCR test or rapid antigen test 1 to 3 days before the party.

However, there were no requirements for vaccination or COVID restriction rules for employees working at the restaurant.

Also, two days before the party, one of the attendees came back from South Africa where the Omicron strain was first detected.

Moreover, participants mingled, drank, and danced with the public at the venue before and after dinner.

In short, the initial data show a widespread transmission of the SARS-CoV-2 at the event.

Subsequently, after exposure, 74 percent of participants were diagnosed with the Omicron variant and requested to self-isolate at home for 10 days.

One case showed no sign of illness (asymptomatic) while 91 percent of participants reported at least three symptoms.

The common symptoms include:

  • cough in 83 percent of cases,
  • runny/stuffy nose (78 percent),
  • fatigue/lethargy (74 percent),
  • sore throat (72 percent),
  • headache (68 percent),
  • and fever (54 percent).

The severity of symptoms were scored from “1” meaning no symptoms to “5” meaning severe.

For most cases the severity level was reported “3” and none of the patients needed hospitalisation.

The authors concluded:

“The preliminary results of our outbreak investigation indicate that the SARS-CoV-2 Omicron VOC is highly transmissible among fully vaccinated young and middle-aged adults.

However, given the specific context of the outbreak in a high-risk setting for transmission, the findings must be interpreted with caution.”

The UK-based ZOE COVID study has added four more omicron symptoms to the above warning signs often seen in cases.

The study was published in the journal Eurosurveillance (Brandal et al., 2021).