What is Vitamin B1 deficiency?

Vitamin B1 (thiamine) deficiency is rare in developed countries, since people usually get enough thiamine from the foods they eat. The most common groups at risk of vitamin B1 deficiency are elderly adults, people with diabetes, and people with HIV/AIDS.

A chronic, severe thiamine deficiency can lead to a disease called beriberi, which causes muscle loss and reduced sensation in the hands and feet (peripheral neuropathy). Because beriberi impairs reflexes and motor function, it can eventually lead to dangerous fluid build-up in the heart and lower limbs.

Common vitamin B1 deficiency symptoms:

  • Weight loss
  • Confusion
  • Memory loss
  • Muscle weakness
  • Enlarged heart
  • Poor reflexes
  • Reduced sensation in hands
  • Reduced sensation in feet
  • Weak immune system

What causes a vitamin B1 deficiency?

  • A diet lacking in vitamin B1-rich foods
  • Alcohol dependence
  • Diuretic medications
  • Aging
  • Diabetes (type 1 and type 2)
  • Bariatric surgery

Further reading: Harvard School of Public Health, National Institutes of Health