Vitamin B1 Requirement

The RDAs for thiamin in the USA were revised in 1998. The minimum suggested amounts for men are 1.2mg per day and 1.1mg for women and slightly more when pregnant or lactating. Thiamin supplements may be useful during times of stress, fever, diarrhea and during and after surgery. Many experts recommend as much as 100mg of thiamin per day for those who drink alcohol.

Raw freshwater fish and shellfish contain an enzyme which breaks down thiamin. This can happen during food storage and preparation or as food passes through the gut. Thus large intakes of raw fish and shellfish can increase the risk of thiamin deficiency. Drinking large quantities of tea and coffee may reduce thiamin absorption.

Deficiency symptoms are still seen in parts of the world where white rice makes up a major part of the daily diet. Those at greatest risk of deficiency include some young children and teenagers, stressed adults, those who exercise very heavily, alcoholics, pregnant women, those on fad diets and people suffering from malabsorption diseases, who are not supplemented with any B1. Marginal deficiencies, without clinical symptoms, may be common among these groups.

Elderly people are also at risk of thiamin deficiency and this may lead to reduced mental functioning, depression, weakness, suppressed immunity and gastrointestinal problems. Early thiamin deficiency may be easily overlooked as the symptoms are generalized and can include fatigue, depression and stress-induced headaches.

Severe thiamin deficiency causes beriberi. Beriberi can affect the cardiovascular system (wet beriberi) and the nervous system (dry beriberi). One of the earliest signs of thiamin deficiency is reduced stamina. Depression, irritability and reduced ability to concentrate are later followed by fatigue, muscle cramps and various pains. Dry beriberi symptoms include numbness and tingling in the toes and feet, stiffness of the ankles, cramping pains in the legs, difficulty walking, and finally, paralysis of the legs with wasting of the muscles. Permanent damage to the nervous system can occur if the deficiency is not corrected in time. Thiamin deficiency may also be associated with reduced tolerance to pain.

Thiamin deficiency can also lead to nausea, lack of appetite, weight loss and constipation. Carbohydrate digestion and the metabolism of glucose are diminished. In the advanced stages of thiamin deficiency, the symptoms of wet beriberi include heart enlargement. Symptoms of cardiac failure such as breathlessness, ankle swelling and fatigue may follow. Marginal thiamin deficiency may contribute to heart disease.


Signs, symptoms & indicators of Vitamin B1 Requirement

Symptoms - General  

Fatigue on light exertion

Like the other B vitamins, thiamin is used to treat fatigue. High-dose thiamin supplementation may be helpful in preventing or accelerating recovery from exercise-induced fatigue. In a small Japanese study, the effects of 100mg per day of thiamin was assessed in 16 male athletes. The athletes exercised on bicycles and changes in blood, heart and lung functioning were measured. In the thiamin supplement group, changes in blood glucose were suppressed and the athletes felt less fatigued. [ Metab Brain Dis, 1996 Mar, 11:1, pp.95-106]


Constant fatigue

Symptoms - Mind - General  

A 'foggy' mind

In a study done in Wales in 1997, researchers gave 120 young adult women either a placebo or 50mg thiamin, each day for 2 months. The women were not thiamin-deficient. Before and after taking the tablets, mood, memory and reaction times were assessed. The women taking the thiamin reported that they felt more clearheaded, composed and energetic. Tests showed no influence on memory but reaction times were faster following supplementation. [Psychopharmacology (Berl), 1997 Jan, 129:1, pp.66-71]

Conditions that suggest Vitamin B1 Requirement


Alzheimer's Disease

Thiamin metabolism appears to be altered in Alzheimer’s with lower levels of thiamin and enzymes which metabolize thiamin found in the brains of Alzheimer’s disease patients. Clinical data suggest that high dose thiamin may have a mild beneficial effect in some patients with Alzheimer’s disease but it does not appear to halt the progress of the disease. [J Geriatr Psychiatry Neurol, 1993 Oct-Dec, 6:4, pp.222-9]


Multiple Sclerosis / Risk

Dr. Fred Klenner, MD pioneered the use of injectable thiamine (vitamin B1) and injectable liver extract for the treatment of multiple sclerosis. His experience and that of others is that early treatment is important in producing symptomatic relief and a state of well-being.


Hydrochloric Acid Deficiency

Please see the link between HCL Deficiency and Zinc Deficiency.


Canker Sores (Aphthous Ulcers)

There is some evidence to suggest that recurring mouth ulcers are due to thiamin deficiency. [Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 1996 Dec, 82:6, pp.634-6]



See the link between Depression and B-complex Need.



A deficiency in thiamine (vitamin B1) makes it harder for your body to break down alcohol. Interestingly, beer contains a good amount of thiamine, but as vitamin B1 oxidizes the alcohol out of the blood in the liver, thiamine is used up and must be replaced.

Organ Health  


38 pateints with chronic open-angle glaucoma (average age of 63 years) were found to have significantly lower blood vitamin B1 (thiamine) levels than 12 normals (average age 53 years) despite roughly equal dietary intakes, suggesting poor thiamine absorption. [Ann Ophthalmol 1979; 11( 7): pp.1095 – 1100]

In glaucoma, thiamine deficiency may be associated with optic nerve atrophy whose symptoms may be at least partly reversible upon restored thiamin status. Most cases of moderate optic atrophy associated with hypovitaminosis B could be cured with 100mg thiamine and vitamin B complex given IM for 10 days and followed by oral supplements. Patients with early or moderate cupping improved visually, and their fields remained static or improved slightly. Intraocular pressure only improved somewhat.

Risk factors for Vitamin B1 Requirement


Alcohol-related Problems

Alcoholics and binge drinkers are especially prone to thiamin deficiency as alcohol reduces absorption, alters metabolism and depletes body stores. Alcoholics also tend to have poor diets. Thiamin deficiency is associated with some of the symptoms of alcoholism such as mental confusion, visual disturbances and staggering gait. If thiamin deficiency is not corrected, permanent brain damage may result. This condition is known as Wernicke Korsakoff syndrome and is usually seen in people who have been addicted to alcohol for many years.

Environment / Toxicity  

Supplements and Medications  

Multiple vitamin supplement use

Symptoms - Gas-Int - General  

Had typical/had severe gastric bypass

Vitamin B1 Requirement suggests the following may be present


Alcohol-related Problems

Alcoholics and binge drinkers are especially prone to thiamin deficiency as alcohol reduces absorption, alters metabolism and depletes body stores. Alcoholics also tend to have poor diets. Thiamin deficiency is associated with some of the symptoms of alcoholism such as mental confusion, visual disturbances and staggering gait. If thiamin deficiency is not corrected, permanent brain damage may result. This condition is known as Wernicke Korsakoff syndrome and is usually seen in people who have been addicted to alcohol for many years.

Recommendations for Vitamin B1 Requirement



Weak or unproven link
Strong or generally accepted link
Strongly counter-indicative
Likely to help



(Vitamin B-1): A B-complex vitamin that acts as a coenzyme necessary for the conversion of carbohydrates into glucose, which is burned in the body for energy. It is essential for the functioning of the nervous system.


(mg): 1/1,000 of a gram by weight.


Excessive discharge of contents of bowel.


Specific protein catalysts produced by the cells that are crucial in chemical reactions and in building up or synthesizing most compounds in the body. Each enzyme performs a specific function without itself being consumed. For example, the digestive enzyme amylase acts on carbohydrates in foods to break them down.


Pertaining to the stomach, small and large intestines, colon, rectum, liver, pancreas, and gallbladder.


Pertaining to the heart and blood vessels.

Nervous System

A system in the body that is comprised of the brain, spinal cord, nerves, ganglia and parts of the receptor organs that receive and interpret stimuli and transmit impulses to effector organs.


Symptoms resulting from an inclination to vomit.


Difficult, incomplete, or infrequent evacuation of dry, hardened feces from the bowels.


The sugars and starches in food. Sugars are called simple carbohydrates and found in such foods as fruit and table sugar. Complex carbohydrates are composed of large numbers of sugar molecules joined together, and are found in grains, legumes, and vegetables like potatoes, squash, and corn.


The chemical processes of living cells in which energy is produced in order to replace and repair tissues and maintain a healthy body. Responsible for the production of energy, biosynthesis of important substances, and degradation of various compounds.


A sugar that is the simplest form of carbohydrate. It is commonly referred to as blood sugar. The body breaks down carbohydrates in foods into glucose, which serves as the primary fuel for the muscles and the brain.


Pertaining to the heart, also, pertaining to the stomach area adjacent to the esophagus.


A pharmacologically inactive substance. Often used to compare clinical responses against the effects of pharmacologically active substances in experiments.

Alzheimer's Disease

A progressive disease of the middle-aged and elderly, characterized by loss of function and death of nerve cells in several areas of the brain, leading to loss of mental functions such as memory and learning. Alzheimer's disease is the most common cause of dementia.

Multiple Sclerosis

Demyelinating disorder of the central nervous system, causing patches of sclerosis (plaques) in the brain and spinal cord, manifested by loss of normal neurological functions, e.g., muscle weakness, loss of vision, and mood alterations.

Hydrochloric Acid

(HCl): An inorganic acidic compound, excreted by the stomach, that aids in digestion.


An essential trace mineral. The functions of zinc are enzymatic. There are over 70 metalloenzymes known to require zinc for their functions. The main biochemicals in which zinc has been found to be necessary include: enzymes and enzymatic function, protein synthesis and carbohydrate metabolism. Zinc is a constituent of insulin and male reproductive fluid. Zinc is necessary for the proper metabolism of alcohol, to get rid of the lactic acid that builds up in working muscles and to transfer it to the lungs. Zinc is involved in the health of the immune system, assists vitamin A utilization and is involved in the formation of bone and teeth.


Lesion on the skin or mucous membrane.


Usually Chronic illness: Illness extending over a long period of time.


A disease of the eye characterized by vision loss due to an increase in the pressure of fluid within the eye. This rise in pressure results from a build-up of aqueous fluid and leads to progressive damage to the optic nerve that transmits visual signals to the brain. Over time, glaucoma can lead to a gradual loss in peripheral vision. There are usually no signs that you're developing glaucoma until vision loss occurs.

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