Thiamine Deficiency (Vitamin B1)

Version 3  |  Updated 16th April 2026
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Thiamine Deficiency (Vitamin B1) 

Patient Information

Hepatology Service

  • Author ID:           JW
  • Leaflet Ref:         SN 007
  • Version:              3
  • Leaflet title:         Thiamine Deficiency (Vitamin B1)
  • Date Produced:   January 2023
  • Expiry Date:        January 2025
 

Introduction

Thiamine Hydrochloride tablets are vitamin tablets (Vitamin (B1); you will have been given these because your body does not have enough Thiamine (Vitamin B1). 

What is Thiamine Hydrochloride and why do I need it?

Thiamine hydrochloride is a synthetic version of natural Thiamine (vitamin B1); this will help to increase the Thiamine levels in your body that your diet alone cannot provide. Your body does not produce Thiamine naturally, so a varied diet is essential. Thiamine (Vitamin B1) is an important nutrient for taking energy from food and turning it into energy for your brain, nerves and heart. When your Thiamine levels are low, this can lead to deficiency and can cause ongoing and lasting health issues. 

What happens if my Thiamine levels are low?                         

Your body stores very little Thiamine, so Thiamine deficiency can happen very quickly, especially if you are not eating very much. Certain conditions can cause lack of Thiamine re-absorption, i.e., Alcohol Excess, Diabetes, HIV/AIDS, Bariatric surgery, anorexia nervosa, Hyperemesis Gravidarum, (HE) (Pregnancy related sickness) ongoing nausea/ vomiting and advanced age.  Sometimes your diet alone cannot provide your body with enough, and Thiamine tablets will be recommended by your health care provider.

What happens if I don’t have enough Thiamine?

As mentioned, your body stores very little Thiamine; if you are not eating much or if you are vomiting for any reason, this can deplete your levels further.  Not having enough Thiamine from your diet alone can cause serious health complications. 

What are the symptoms of Thiamine Deficiency?

  • Blurred or double vision
  • Facial weakness
  • Memory loss Rapid heartbeat
  • Dizziness
  • Leg swelling
  • Numbness to face hands and feet
  • Loss of balance
  • Loss of muscle power
  • Struggling to urinate

 

If Thiamine deficiency is severe, serious health problems can occur.  Always consult your health care provider

Where can I get Natural Thiamine?

Thiamine can be found in Thiamine enriched foods, eating a varied diet including poultry, meat, fish, cereals, beans, fresh vegetables, some dairy.

 

Some foods can inhibit Thiamine absorption also; these include coffee, chocolate, black tea and alcohol.

 

What will be the benefits to taking Thiamine?

Taking Thiamine will help to prevent complications of the nervous system, heart and brain. Vitamin B1, or Thiamine, enables the body to use carbohydrates and turn them in to energy, which is essential for body function, if your health care adviser thinks you are at risk of developing Thiamine deficiency, you should be offered Thiamine.  Fortunately, Thiamine Deficiency is usually easy to reverse with supplementation.

Follow up

Your GP will be able to manage this medication for you, and it is important you continue to take it as prescribed.

Dosing

Thiamine 50mg Tablets, 4 times a day, 7 days a week.

Last modified 16th April 2026 11:03:14 am