You need this vitamin for healthy immune function and for protecting against infectious respiratory illnesses like COVID-19. If you're expecting to get enough from the food you eat, you may be dismayed to learn that levels of this nutrient have recently plummeted throughout the food chain.
Ominous B1 Deficiency Found Throughout Food Chain

STORY AT-A-GLANCE
Vitamin B1 (thiamine) is used by nearly all your cells, metabolizing the carbohydrates and lipids in the foods you eat, helping to convert food into energy and boosting the flow of electrolytes in and out of your nerves and muscles
Thiamine is important for healthy immune function, and may actually be crucial to protect against infectious respiratory illnesses such as COVID-19
While thiamine deficiency is often the result of alcohol misuse, chronic infections, poor nutrition and/or malabsorption, recent research suggests vitamin B1 has dramatically declined throughout the food chain in recent years
The transfer of thiamine up the food chain may be blocked by a number of factors, including the overabundance of thiaminase, an enzyme that destroys thiamine. Thiaminase is naturally present in certain microorganisms, plants and fish that have adapted to use it to their advantage
Thiamine deficiency has been identified in dozens of animal species and is now suspected of driving declines in wildlife populations across the northern hemisphere. This means our diets are likely to be low in thiamine, thereby raising the risk for thiamine deficiency in the human population
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This article was previously published February 8, 2021, and has been updated with new information.
Vitamin B1 (thiamine) is used by nearly all your cells, and helps to metabolize the carbohydrates and lipids in the foods you eat. It also facilitates converting your food into energy and boosting the flow of electrolytes in and out of your nerves and muscles. It's considered "essential" because your body can't produce it on its own; it must come from an outside source.
Thiamine is sometimes referred to as an "antistress" vitamin for its positive influence on your central nervous system, and it's also important for healthy immune function. In addition to nutrients such as zinc and vitamins C and D, vitamin B1 (thiamine) may actually be crucial to protect against infectious respiratory illnesses such as COVID-19.
Thiamine deficiency syndrome (beriberi) has also been implicated in other types of severe infections and bears many similarities to sepsis. This is one of the reasons why thiamine is such an important part of Dr. Paul Marik's sepsis treatment.1 Sepsis, in turn, is a major contributor in influenza deaths in general, and a primary cause for COVID-19 deaths specifically.
While thiamine deficiency is often the result of alcohol misuse, chronic infections, poor nutrition and/or malabsorption, recent research suggests vitamin B1 availability has dramatically declined throughout the food chain in recent years.2
Lack of Thiamine Is Disrupting Ecosystem
In a January 28, 2021, article in Hakai Magazine,3 Alastair Bland reviews findings showing certain marine ecosystems are being decimated by an apparent lack of thiamine. Problems were noticed in January 2020 at salmon hatcheries in California. Fish were acting disoriented and mortality was surprisingly high.
Initially, they feared a virus might be at play, but after digging through the medical literature, they found research discussing thiamine deficiency in marine life. As noted in the article, vitamin B1 is "a basic building block of life critical to the functioning of cells and in converting food into energy."
Biologists tested the theory by dissolving thiamine powder into the water, and within hours, nearly all of the fish were acting normally again. Meanwhile, the behavior of fish in an untreated batch continued to decline. As a result of this research, many hatcheries took to applying thiamine, but the underlying problem still remains.
"Since the fish acquire thiamine by ingesting it through their food, and females pass nutrients to their eggs, the troubling condition indicated that something was amiss in the Pacific Ocean, the last place the fish eat before entering fresh water to spawn," Bland writes, adding:
"California researchers now investigating the source of the salmon's nutritional problems find themselves contributing to an international effort to understand thiamine deficiency, a disorder that seems to be on the rise in marine ecosystems across much of the planet.
It's causing illness and death in birds, fish, invertebrates, and possibly mammals, leading scientists from Seattle to Scandinavia to suspect some unexplained process is compromising the foundation of the Earth's food web by depleting ecosystems of this critical nutrient."
What's Causing Ecosystem-Wide Thiamine Deficiency?
As explained by Bland, "Thiamine originates in the lowest levels of the food web." Certain species of bacteria, phytoplankton, fungi and even some plants are responsible for synthesizing thiamine from other precursor compounds.
From there, thiamine makes its way through both the animal and plant kingdoms. All organisms need it. In animals, enzymes interact with thiamine to generate cellular energy. Without sufficient amounts of thiamine, fundamental metabolic processes start to fail, causing neurological disturbances, reproductive problems and increased mortality.
While beriberi has been recognized as a serious health risk in humans for nearly 100 years, and thiamine supplementation has been standard practice for domesticated livestock such as sheep, cattle, mink and goats for several decades,4 the presence in and effect of thiamine deficiency on wildlife wasn't discovered until the 1990s, when Canadian scientist John Fitzsimons started investigating the decline in Great Lakes trout. Bland writes:5
"Studying lake trout born in captivity, Fitzsimons observed symptoms like hyperexcitability, loss of equilibrium, and other abnormal behavior.
He wondered if a nutritional deficiency was at play, and to test for this he dissolved various vitamin tablets in water and — using trout in different life stages, including fertilized eggs — administered the solutions to the fish, both through injection and baths.
The idea was to see which vitamin, if any, cured the condition. 'It came down to a range of B vitamins, and it was only the thiamine that was able to reverse the signs I was seeing,' he says."
Since the publication of Fitzsimons' findings in 1995, thiamine deficiency has been identified in dozens of animal species, including birds and moose. While severe deficiency has lethal consequences, sublethal deficiency can have insidiously devastating effects, including:6
Lowering strength and coordination
Reducing fertility
Impairing memory and causing other neurobehavioral deficits.7 In humans, thiamine deficiency has been shown to play a role in cases of delirium. In one study,8 45% of cancer patients suffering from delirium had thiamine deficiency, and 60% recovered when treated with intravenous thiamine
Paralysis
Loss of vocalization
B1 Deficiency May Be Responsible for Wildlife Declines
Thiamine deficiency is now suspected of driving declines in wildlife populations all across the northern hemisphere.9 Bland cites research showing marine and terrestrial wildlife populations declined by half between 1970 and 2012. Between 1950 and 2010, the global seabird population declined by 70%.10
The transfer of thiamine up the food chain may be blocked by a number of factors, including overfishing. But there's yet another possibility, and that is the overabundance of thiaminase, an enzyme that destroys thiamine. Thiaminase is naturally present in certain microorganisms, plants and fish that have adapted to use it to their advantage.
While habitat loss and other environmental factors are known to impact biodiversity, these declines are allegedly occurring far faster than can be explained by such factors. Researchers strongly suspect human involvement, but how?
"Scientists are floating various explanations for what's depriving organisms of this nutrient, and some believe that changing environmental conditions, especially in the ocean, may be stifling thiamine production or its transfer between producers and the animals that eat them," Bland writes.11
"Sergio Sañudo-Wilhelmy, a University of Southern California biogeochemist, says warming ocean water could be affecting the populations of microorganisms that produce thiamine and other vitamins, potentially upsetting basic chemical balances that marine ecosystems depend on.
'In different temperatures, different phytoplankton and bacteria grow faster,' he says. This, he explains, could hypothetically allow microorganisms that do not produce thiamine — but, instead, acquire it through their diet — to outcompete the thiamine producers, effectively reducing thiamine concentrations in the food web."
The transfer of thiamine up the food chain may be blocked by a number of factors, including overfishing. But there's yet another possibility, and that is the overabundance of thiaminase, an enzyme that destroys thiamine. Thiaminase is naturally present in certain microorganisms, plants and fish that have adapted to use it to their advantage.
"When larger animals eat prey containing thiaminase, the enzyme rapidly destroys thiamine and can lead to a nutritional deficiency in the predator," Bland explains. One thiaminase-rich species is an invasive species of herring called alewife, which during the 20th century have spread through the Great Lakes, displacing native species.
This, some researchers believe, has led to chronic and severe thiamine deficiency in larger fish species. "The Great Lakes' saga illustrates the outsized impact that one single nutrient can have on an entire ecosystem," Bland writes.
An overabundance of thiaminase-containing species also appears to be responsible for the decline in Sacramento River salmon. In this case, northern anchovy, which is rich in thiaminase, is the suspected culprit.
Unfortunately, few answers have emerged as of yet. Giving thiamine to fish in hatcheries is not a long-lasting solution, because once they re-enter the wild, the deficiency reemerges. One scientist likened the practice to "sending a kid with a fever off to school after giving them a Tylenol."12
Signs and Symptoms of Thiamine Deficiency
Considering both plants and wildlife are becoming increasingly thiamine-deficient, it's logical to suspect that this deficiency is becoming more common in the human population as well. Early symptoms of thiamine deficiency include:13,14
Fatigue and muscle weakness
Confusion and/or memory problems
Loss of appetite and weight loss
Numbness or tingling in arms or legs
As your deficiency grows more severe, the deficiency can progress into one of four types of beriberi:15
Paralytic or nervous beriberi (aka "dry beriberi") — Damage or dysfunction of one or more nerves in your nervous system, resulting in numbness, tingling and/or exaggerated reflexes
Cardiac ("wet") beriberi — Neurological and cardiovascular issues, including racing heart rate, enlarged heart, edema, breathing problems and heart failure
Gastrointestinal beriberi — Nausea, vomiting, abdominal pain and lactic acidosis
Cerebral beriberi — Wernicke's encephalopathy, cerebellar dysfunction causing abnormal eye movements, ataxia (lack of muscle coordination) and cognitive impairments. If left untreated, it can progress to Korsakoff's psychosis, a chronic brain disorder that presents as amnesia, confusion, short-term memory loss, confabulation (fabricated or misinterpreted memories) and in severe cases, seizures