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Doctor's Assessment Included

Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

Vitamins

Vitamin B1 (Thiamine)

Vitamin B1 (thiamine) is considered important for energy metabolism, which may become less efficient with age. Some older adults may have reduced absorption. Monitoring levels can help healthcare providers support healthy ageing strategies.

Reference Ranges

Male
nmol/l
Low 66.5 Normal 200 High
Female
nmol/l
Low 66.5 Normal 200 High

Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.

What It Measures

This test measures thiamine (vitamin B1) levels in your blood, expressed in nmol/l. It may help assess whether your body has adequate thiamine to support energy metabolism and neurological function. Your healthcare provider can interpret results in context.

Why It Matters

For adults over 60, adequate thiamine may support cognitive function and energy levels. Age-related changes in absorption may increase the risk of insufficiency. A healthcare provider can assess whether supplementation or dietary adjustments may be beneficial.

When to Test

Testing may be considered when experiencing unexplained fatigue, tingling in extremities, or cognitive difficulties. Healthcare providers may also recommend testing for individuals with restrictive diets, chronic alcohol use, or gastrointestinal conditions that may affect absorption.

Symptoms

Low Levels

Some people with low vitamin B1 may experience fatigue, irritability, poor memory, or tingling in the hands and feet. In more pronounced cases, muscle weakness and difficulty walking have been reported. A healthcare provider can help determine the cause.

High Levels

Elevated vitamin B1 levels are generally considered uncommon since excess thiamine is typically excreted by the kidneys. Some people may rarely experience mild reactions. If your levels appear elevated, your healthcare provider can advise on appropriate next steps.

Lifestyle Tips

Foods considered rich in thiamine include whole grains, legumes, pork, and fortified cereals. Some people may benefit from reducing processed food intake. Cooking methods such as steaming may help preserve thiamine content. Discuss dietary changes with your healthcare provider.

Frequently Asked Questions

What foods are high in vitamin B1?
Foods generally considered good sources of thiamine include whole grains, pork, legumes, nuts, and fortified cereals. Your healthcare provider or a dietitian can help you plan a balanced diet that supports adequate B1 intake.
Can vitamin B1 deficiency cause nerve damage?
Prolonged thiamine deficiency may be associated with nerve damage in some cases. This is sometimes referred to as peripheral neuropathy. Early detection through testing and consultation with your healthcare provider may help address concerns before they progress.
Does alcohol affect vitamin B1 levels?
Chronic alcohol consumption is believed to impair thiamine absorption and increase its excretion. Healthcare providers may recommend B1 monitoring for individuals with significant alcohol intake. Discuss your specific situation with a qualified professional.