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Thiamine - Vitamin B1

Athiam, ThiaDose, ThiamEss

Peer reviewed by Sid DajaniLast updated by Michael Stewart, MRPharmSLast updated 12 Nov 2021

Meets Patient’s editorial guidelines

Thiamine is a type of vitamin B.

It is recommended as a vitamin supplement for people who cannot get sufficient vitamin B1 from their normal diet.

It is unlikely to cause side-effects.

In this article:

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About thiamine

Type of medicine

Vitamin B1

Used for

Thiamine deficiency

Also called

Athiam®; ThiaDose®; ThiamEss®

Available as

Tablets, modified-release tablets

Thiamine is a type of vitamin B. Several different substances belong to the group of vitamins known as the B vitamins. Thiamine is known as vitamin B1.

Foods that are good natural sources of thiamine are cereals, nuts, peas, beans and pork. Although thiamine deficiency tends to be rare in the UK, your doctor may recommend that you take a supplement of thiamine if for some reason you cannot get sufficient vitamin B1 from your normal diet.

Thiamine is also an ingredient of a number of multiple-vitamin preparations that are available to buy without a prescription.

Before taking thiamine

To make sure that this is the right treatment for you, before you start taking thiamine it is important that you speak with a doctor or pharmacist:

  • If you are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.

  • If you have ever had an allergic reaction to a medicine.

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How to take thiamine

  • Before you start taking thiamine, read the manufacturer's printed information leaflet from inside the pack.

  • Thiamine tablets are usually taken once a day. Doses of 25-100 mg are sufficient to prevent mild deficiency. You can take the tablets at whatever time of day you find easiest to remember, either before or after meals. If you have been prescribed a higher dose (200-300 mg daily), your doctor will recommend that you take this as one tablet (100 mg) two or three times a day.

  • Do not take more than the dose which has been recommended or prescribed.

Getting the most from your treatment

  • It is likely that your doctor will give you some lifestyle and dietary advice. It is important you follow any recommendations you are given about eating a well-balanced diet and not drinking alcohol.

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Can thiamine cause problems?

Thiamine is unlikely to cause any side-effects at the recommended doses. If, however, you experience any symptoms which you think may be due to the tablets, please speak with your doctor or pharmacist for further advice.

How to store thiamine

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital for advice. Take the container with you, even if it is empty.

This medicine is for you. Do not give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about the medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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