Thiamine Deficiency

What is a thiamine deficiency?

A thiamine deficiency means your body doesn’t have enough thiamine (vitamin B1) to function properly. Your body needs thiamine to stay healthy. Specifically, thiamine helps with cell function, growth, development and converting food into energy.

Consistently low thiamine levels can negatively impact your heart, immune system and nervous system. Symptoms like fatigue, loss of appetite and nerve damage can start in as little as three weeks.

Thiamine deficiency is rare in areas with regular access to food and supplements. But certain conditions can cause low thiamine even if you have access to these things. In the United States, most people with thiamine deficiency experience it as a symptom of another health condition.

The term “beriberi” refers to severe thiamine deficiency.

What are the symptoms of low thiamine?

Thiamine deficiency symptoms may be vague, and they often mimic symptoms of other conditions. They can include:

• Balance issues
• Blurred vision
• Confusion
• Delirium
• Fatigue
• Hallucinations
• Irritability
• Loss of appetite
• Mental impairment
• Nausea and vomiting
• Tingling and burning in your arms and legs
• Short-term memory issues

Tell your healthcare provider if you develop any of these symptoms. They can run tests to determine the cause.

What causes thiamine deficiency?

Causes of thiamine deficiency include:

• Conditions that increase your need for thiamine, like hyperthyroidism
• Conditions that disrupt how your body metabolizes thiamine, like liver disease
• Conditions that prevent your body from absorbing thiamine, like chronic diarrhea
• Some medications, like certain diuretics, cardiovascular drugs and antiseizure medications

Not getting enough thiamine in your diet can also cause thiamine deficiency. This can happen in people who mainly eat highly processed carbohydrates like white rice, white sugar and white flour. It also occurs in people with severe anorexia nervosa due to a lack of food intake.

Thiamine deficiency risk factors

A risk factor is something that increases your chance of developing a certain condition. Even though thiamine deficiency is rare, these things could raise your risk:

• Alcohol use disorder
• Congenital beriberi (being born without the ability to absorb thiamine)
• Kidney disease
• Lack of access to nutritious foods
• Prior gastric bypass surgery
• Poor diet or starvation
• Wernicke-Korsakoff syndrome (a memory disorder linked to thiamine deficiency and alcohol use disorder

Babies who drink breast milk (chest milk) from parents with thiamine deficiency have a higher risk of developing it, too.

What are the complications of thiamine deficiency?

Left untreated, thiamine deficiency can lead to serious and life-threatening complications like:

• Brain damage (encephalopathy)
• Cognitive impairment
• Coma
• Congestive heart failure
• Loss of coordination (ataxia)
• Nerve damage (can be permanent in severe cases)
• Memory loss
• Muscle atrophy (reduced muscle mass)

How is thiamine deficiency diagnosed?

A healthcare provider will do a physical examination and check for obvious symptoms. They’ll also run blood tests to confirm a diagnosis.

Providers can’t directly measure the level of thiamine in your blood. But they can check the activity of an enzyme called transketolase. Transketolase needs thiamine to work. So, if a blood test reveals low transketolase activity, it points to a lack of thiamine.

How do you fix low thiamine?

The only way to fix low thiamine is to get more of it into your system. Adults need between 1.1 to 1.2 milligrams of thiamine every day. Ideally, you can hit this quota by eating thiamine-rich foods. But if you have severe thiamine deficiency, you’ll need supplements to replenish your body’s stores.

Thiamine-rich foods

Keep your thiamine levels healthy by eating foods like:

• Black beans
• Enriched or fortified white carbs (rice, bread, flour)
• Fish (salmon)
• Lentils
• Macadamia nuts
• Pork
• Seafood (mussels)
• Sunflower seeds
• Whole wheat bread
• Yogurt

Thiamine supplements

Sometimes, food isn’t enough to raise your thiamine levels quickly. You may need to take a supplement, too. Over-the-counter options include multivitamins or vitamin B complex formulas.

But you may need high-dose supplementation if you have a severe thiamine deficiency. Under medical supervision, a healthcare provider can give you thiamine in one of these forms, from least to most involved:

• Tablets
• Injections
• IV (intravenous) infusions

How long does it take to reverse thiamine deficiency?

It depends on the severity of your condition and how long you’ve been deficient. For instance, some heart symptoms can go away within the first few hours or days. But nerve and motor symptoms can take up to six months to improve. In severe cases, nerve damage can be permanent.

Your healthcare provider will continue to supplement thiamine until your levels return to normal. This can look different for everyone, so it’s important to ask your provider what to expect in your situation.

Can thiamine deficiency be prevented?

The only way to prevent thiamine deficiency is to eat thiamine-rich foods. If you have a condition that affects your thiamine levels, be sure to manage it well and follow your provider’s recommendations. You should also see your healthcare provider for regular checkups.

What’s the outlook for people with thiamine deficiency?

When diagnosed and treated early, thiamine deficiency is reversible. Most symptoms should go away once your thiamine levels return to normal.

But in severe or untreated cases, thiamine deficiency can result in serious complications or even death.

When should I see my healthcare provider?

You should see your healthcare provider any time you develop new or troubling symptoms. Even if your symptoms end up pointing to another condition, it’s important to get a diagnosis as soon as possible so you can start treatment.