Vitamin B1 (thiamine) deficiency is the underlying cause of several clinical syndromes, including Wernicke's encephalopathy, wet beriberi, and dry beriberi, rather than a single clinical condition or diagnosis.
Clinical presentation depends on the chronicity of the deficiency.
As signs and symptoms are non-specific, the presence of risk factors raises suspicion of the diagnosis.
Risk factors include alcohol dependence, malabsorption, and a diet low in thiamine (e.g., based on polished rice).
As there is no rapid diagnostic test for the condition, presumptive treatment should be commenced immediately if vitamin B1 deficiency is suspected.
Untreated vitamin B1 deficiency in the form of Wernicke's encephalopathy can result in the need for institutional care, or in death.
Vitamin B1, also known as thiamine, is an essential micronutrient. Deficiency can result in distinct clinical presentations. Acute deficiency can present as Wernicke's encephalopathy with ocular abnormalities, mental state changes, and ataxia. Acute or chronic deficiency can also lead to wet beriberi (which presents as high-output cardiac failure with oedema and orthopnoea), or low-output cardiac failure with lactic acidosis and peripheral cyanosis (also known as Shoshin beriberi). Dry beriberi occurs with chronic deficiency and is characterised by a distal peripheral polyneuropathy.
History and exam
- confusion (Wernicke's encephalopathy)
- ataxia (Wernicke's encephalopathy)
- muscle aches
- incessant crying (infantile beri-beri)
- anorexia (infantile beri-beri)
- bulging fontanelle (infantile beri-beri)
- dyspnoea (wet beriberi)
- orthopnoea (wet beriberi)
- tachycardia (wet beriberi)
- peripheral cyanosis (wet beriberi)
- peripheral oedema (wet beriberi)
- decreased sensation (dry beriberi)
- reduced tendon reflexes (dry beriberi)
- muscle weakness (dry beriberi)
- muscle wasting (dry beriberi)
- chronic alcohol excess
- staple diet of polished rice
- age <1 year in endemic thiamine deficient region
- refeeding/total parenteral nutrition
- hyperemesis gravidarum
- recurrent vomiting/chronic diarrhoea
- gastrointestinal surgery
- magnesium deficiency
- HIV infection/AIDS
- cancer and chemotherapy
- thiaminase- and thiamine antagonist-containing diet
- genetic mutation
Jennifer Logue, MBChB, MRCP, MD, FRCPath
Reader and Honorary Consultant in Metabolic Medicine
Lancaster University Medical School
JL declares that she has no competing interests.
Mike Lean, MA, MB, BChir, MD, MRCP, FRCPS, FRCP
Professor of Human Nutrition
University of Glasgow
ML declares that he has no competing interests.
William Marshall, MA, MB, BS, PhD, MSc, FRCP, FRCPath, FRCPEdin, FSB
Emeritus Reader in Clinical Biochemistry
King's College London
Clinical Director of Pathology
The London Clinic
WM declares that he has no competing interests.
Linda Edwards, MD
Chief and Associate Professor of Medicine
Division of General Internal Medicine
Department of Medicine
University of Florida College of Medicine
LE declares that she has no competing interests.
Martin Crook, BSc, MB, BS, MA, PhD, FRCPath, FRCPI, FRCP
Consultant Chemical Pathologist
MC declares that he has no competing interests.
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