Symptoms, conditions and causes

What are the signs of thiamine deficiency?

Vitamin B1 is intimately involved with the function of the mitochondria, so if you’re deficient, low energy is one of the first symptoms.

The more carbs and sugar you consume, the more B1 you need. This is because vitamin B1 is necessary to burn glucose. Even on a ketogenic diet, you'll still burn glucose for certain functions of the body. Vitamin B1 is water soluble, so it isn't stored in the body for long periods. This makes it easier to become deficient.

B1 is also important for the myelin sheath—the coating on your nerves. B1 is crucial for the proper function of the autonomic nervous system and specifically affects the vagus nerve.

The following conditions and symptoms are related to a deficiency in vitamin B1:

•Gastroparesis (slow digestive system)


•Peripheral neuropathy

•Regurgitation of bile

•Excessive sweating or no sweating at all

•Excessive tears or no tears at all

•Dizziness when standing up


•Low tolerance for stress

•Trouble regulating body temperature

•Increased pulse rate

If you have a more severe B1 deficiency, you might experience the following:

•Enlarged heart



•Memory loss



•Hearing loss

•Sleep apnea

•Trouble breathing

Last updated: Feb 05, 2024 15:48 PM