(thiamine deficiency, vitamin deficiency)

A deficiency of thiamine (vitamin B1).
It can affect the cardiovascular system or nervous system, causing heart failure or muscle paralysis.
It is rare in western countries, where most people get enough thiamine in their diet, but remains relatively common in sub-Saharan Africa.

Thiamine breaks down and digests the foods to keep the metabolism going and help the muscles and nervous system work effectively.

(Types)
• wet beriberi: Affects the cardiovascular system, resulting in a tachycardia, dyspnea (shortness of breath), and leg swelling (peripheral edema). It is a life-threatening medical emergency.
• dry beriberi: Affects the peripheral nervous system, resulting in numbness of the hands and feet, trouble moving the legs, pain, and extreme muscle wasting as well as anorexia (loss of appetite) and constipation. It can also affect the central nervous system (CNS), resulting in confusion and so on.
• infantile beriberi (acute beriberi): Presents with anorexia, vomiting, lactic acidosis, arrhythmia, and cardiomegaly. Found mostly in babies of malnourished mothers.
• gastrointestinal beriberi: Affects the digestive system and other bodily systems.

(Types: dry beriberi)
• Wernicke encephalopathy
- - visual changes, abnormal involuntary eye movements, droopy eyelids
- - ataxia: Inability to coordinate voluntary movements.
- - confusion
- - muscle loss (in some cases)
• Korsakoff syndrome
- - severe memory loss
- - inability to form new memories
Korsakoff syndrome can be preceded by an episode of Wernicke encephalopathy (Wernicke-Korsakoff syndrome), but not always.

(Risk factors)
• alcoholism: Excess alcohol can interfere with the body's ability to absorb thiamine. It can induce dry beriberi that manifests as acute inflammatory demyelinating polyneuropathy in a patient with decompensated alcohol-induced cirrhosis.
• breastfed babies: In case their mothers are thiamine-deficient.
• high-carbohydrate diet especially refined carbs
• extremely high amounts of physical activity or exercise
• hyperthyroidism: Prevents thiamine absorption.
• certain digestive problems: Interfere with nutrient absorption, particularly in the older ages.
• bariatric surgery for weight loss
• high levels of stress
• dialysis
• chronic diarrhea
• high doses of diuretics
• diet of mostly white rice: Non-enriched white rice has only about one-tenth of the vitamin B1 content of non-enriched brown rice.
• genetic condition that results in difficulties absorbing thiamine found in food

(Diagnosis)
• symptoms
• low levels of thiamine in the urine
• high blood lactate
• improvement with thiamine supplementation

(Treatment)
• diet with enough thiamine: E.g. beans and legumes, seeds, meat, fish, whole grains, nuts, dairy, vegetables (e.g. asparagus, acorn squash, Brussels sprouts, spinach, beet greens).
thiamine-enriched foods
• thiamine supplementation either by mouth or injection
The symptoms generally resolve in a few weeks.