Vitamin B1 deficiency

Vitamin B1, thiamin, or thiamine, enables the body to use carbohydrates as energy. It is essential for glucose metabolism, and it plays a key role in nerve, muscle, and heart function.

Vitamin B1 is a water-soluble vitamin, as are all vitamins of the B complex.

Vitamins are classified according to the materials they dissolve in. Some dissolve in water, and others dissolve in fat. Water-soluble vitamins are carried through the bloodstream. Whatever the body does not use is eliminated in urine.

Foods

There are high concentrations of Vitamin B1 in the outer layers and germ of cereals, as well as in yeast, beef, pork, nuts, whole grains, and pulses.

Fruit and vegetables that contain it include cauliflower, liver, oranges, eggs, potatoes, asparagus, and kale.

Other sources include brewer’s yeast and blackstrap molasses.

Breakfast cereals and products made with white flour or white rice may be enriched with vitamin B.

In the United States, people consume around halfTrusted Source of their vitamin B1 intake in foods that naturally contain thiamin, while the rest comes from foods that are fortified with the vitamin.

Heating, cooking, and processing foods, and boiling them in water, destroy thiamin. As vitamin B1 is water-soluble, it dissolves into cooking water. White rice that is not enriched will contain only one tenth of the thiamin available in brown rice.

The National Institutes of Health (NIH) Office of Dietary Supplements (ODS) note that one serving of fortified breakfast cereal provides 1.5 milligramsTrusted Source (mg) of thiamin, which is more than 100 percent of the daily recommended amount.

One slice of whole wheat bread contains 0.1 mg, or 7 percent of the daily requirement. Cheese, chicken, and apples contain no thiamin.

Humans need a continuous supply of vitamin B1, because it is not stored in the body. It should be part of the daily diet

Benefits

Vitamin B1, or thiamin, helps prevent complications in the nervous system, brain, muscles, heart, stomach, and intestines. It is also involved in the flow of electrolytes into and out of muscle and nerve cells.

It helps prevent diseases such as beriberi, which involves disorders of the heart, nerves, and digestive system.

Uses in medicine

Patients who may receive thiamin to treat low levels of vitamin B1 include those with peripheral neuritis, which is an inflammation of the nerves outside the brain, or pellagra.

People with ulcerative colitis, persistent diarrhea, and poor appetite may also receive thiamin. Those who are in a coma may be given thiamin injections.

Some athletes use thiamin to help improve their performance. It is not a prohibited substances for athletes in the U.S.

Other conditions in which thiamin supplements may help include:

• AIDS
• canker sores
• cataracts
• glaucoma and other vision problems
• cerebellar syndrome, a type of brain damage
• cervical cancer
• diabetic pain
• stress
• heart disease
• kidney disease in patients with diabetes type 2
• motion sickness
• a weakened immune system.

Symptoms of thiamine (B1) deficiency

Signs and symptoms of thiamine deficiency can be easy to overlook, as they can be nonspecific and vague, sometimes mimicking symptoms of other conditions (4Trusted Source).

Below are some of the most common symptoms of thiamine deficiency.

1. Loss of appetite

• Experiencing an atypical loss of appetite can be one of the earliest symptoms of thiamine deficiency. Losing your appetite (not feeling hungry) can lead to unintentional weight loss, which can be problematic or unsafe.
• One theory behind this is that thiamine may play a key role in regulating hunger and fullness cues in the brain. Inadequate stores of thiamine may disrupt how well this process works, making you feel full even when you may not actually be (5Trusted Source).
• As a result, you may eat less than you usually would, due to a lack of appetite. This could cause you to potentially miss out on vital nutrients.
• Animal studies have demonstrated this relationship. For instance, one study found that rats ate significantly less food after receiving a diet deficient in thiamine for 16 days. Their food intake dropped by almost 75% by day 22 (5Trusted Source).
• Furthermore, an increase in appetite and return to usual food intake returned once thiamine was added back to their diet.

2. Fatigue

• Being deficient in thiamine can show up as fatigue (tiredness), which may come on quickly or over time, depending on the severity of the deficiency. Some sources suggest fatigue can occur within just a few weeks of deficiency (2Trusted Source).
• This symptom makes sense, given the role of thiamine in converting food into energy. Not having enough thiamine in the body means that it cannot produce as much energy to use as fuel.
• While fatigue is a widespread symptom that can indicate a number of other health conditions, many studies have linked it to thiamine deficiency (6Trusted Source, 7Trusted Source).
• In fact, some researchers suggest that fatigue should be prioritized when identifying early signs of thiamine deficiency among people at risk for it (8Trusted Source).

3. Irritability

• Having a thiamine deficiency may cause some changes in your mood, such as making you more irritable or easily upset.
• Feeling irritable is often among the earliest signs of thiamine deficiency, and it may present alongside fatigue within just a few weeks (2Trusted Source).
• Babies with thiamine deficiency frequently express increased irritability as a symptom (9Trusted Source, 10Trusted Source).

4. Nerve damage

• Among the most well-known side effects of prolonged, severe thiamine deficiency (beriberi) is damage to the nerves, also known as neuropathy.
• In fact, neuropathy from thiamine deficiency was among the first deficiency syndrome identified in humans (2Trusted Source).
• There are two types of beriberi that can occur: wet beriberi and dry beriberi.
• Wet beriberi includes heart failure, whereas dry beriberi occurs without heart failure. Wet beriberi is considered an emergency and can lead to death within a few days if not treated (2Trusted Source, 11Trusted Source).

Potential symptoms of beriberi can include (12Trusted Source, 13):

• tingling limbs
• loss of sensitivity in feet and fingers
• muscle weakness
• rapid heartbeat
• difficulty waking up
• mental confusion
• coordination problems
• lower body paralysis (inability to move the legs)

5. Tingling arms and legs

• Even though tingling — the sensation of prickliness and “pins and needles” in your arms and legs, also called paresthesia — can be a symptom of severe beriberi, it can also be an earlier symptom of thiamine deficiency. It generally comes before more widespread, brain-related symptoms (14Trusted Source).
• The reason behind this symptom is that thiamine is required for the expected function of the nerves that reach your arms and legs. When there’s not enough thiamine present, paresthesia can result (15Trusted Source).
• Over time, untreated thiamine deficiency can lead to more serious damage to these peripheral nerves (16Trusted Source).

6. Blurry vision

• Because of the role thiamine plays in maintaining healthy nerves, a deficiency can affect the optic nerve in your eyes.
• Specifically, this can cause swelling of the optic nerve that leads to blurred vision. Left untreated, optic nerve damage can eventually result in vision loss.
• Some small studies have found that supplementation used to correct thiamine deficiency may also significantly improve vision in these instances (18Trusted Source, 19Trusted Source, 20Trusted Source).
• In an animal study, researchers found that a thiamine compound was effective for preventing alcohol-induced optical nerve damage (21Trusted Source).
• However, the human studies are “case reports,” meaning they followed a single individual. Plus, the results of animal studies don’t always hold true when applied to human health. That means we can’t apply this research to the general population, and we need more studies.

7. Nausea and vomiting

• Like fatigue and irritability, nausea and vomiting can be nonspecific symptoms of many conditions, including thiamine deficiency.
• These digestive symptoms are more common among people with a thiamine deficiency–related condition called Wernicke encephalopathy. However, they can be a primary symptom even in mild cases of thiamine deficiency, so it’s important to take them seriously (8Trusted Source, 22Trusted Source, 23Trusted Source).

8. Delirium

Thiamine deficiency can lead to delirium, a serious condition in which you experience:

• confusion
• reduced awareness of your environment
• an inability to think clearly

Severe thiamine deficiency can lead to the development of Wernicke-Korsakoff syndrome (WKS), which involves brain damage and has symptoms of:

• delirium
• confusion
• hallucinations
• memory loss

Risk Factors for Thiamine Deficiency

Several factors increase your risk of developing a thiamine deficiency. Because it is rare, most people with risk factors will not get thiamine deficiency. However, those who are experiencing the following may be more at risk:

• Alcoholism
• Gastric bypass surgery
• Genetic beriberi (inability to absorb thiamine)
• Kidney disease
• Starvation
• Poor diet
• No or limited access to nutritious foods

Diagnosis of Thiamin Deficiency

• Physical examination
• Relief of symptoms when thiamin supplements are taken
• The diagnosis of thiamin deficiency is based on symptoms.
• Tests to confirm the diagnosis are not readily available. Blood tests to measure electrolyte levels are usually done to exclude other possible causes.
• The diagnosis is confirmed if thiamin supplements relieve symptoms.
• Treatment of Thiamin Deficiency
• Thiamin supplements

All forms of thiamin deficiency are treated with thiamin supplements. They are usually given by mouth. They are given intravenously if symptoms are severe. Because thiamin deficiency often occurs with other B vitamin deficiencies, multivitamins are usually given for several weeks. People are encouraged to eat healthily and are advised to consume 1 to 2 times the daily recommended intake of vitamins. They should not drink any alcohol.

Wernicke-Korsakoff syndrome, a medical emergency, is treated with high doses of thiamin given intravenously or by injection into a muscle (intramuscularly) for several days. Use of alcohol should be stopped.

When people who may have a thiamin deficiency, particularly alcoholics, must be fed intravenously, they are given thiamin supplements first. These intravenous solutions contain glucose. Because thiamin is needed to process (metabolize) glucose, glucose may trigger or worsen symptoms of thiamin deficiency. Giving them thiamin supplements first can prevent Wernicke-Korsakoff syndrome from developing or worsening.

With treatment, most people recover completely. In some people with Wernicke-Korsakoff syndrome, some brain damage is permanent. Symptoms of beriberi may recur years after apparent recovery.