What is thiamine or Vitamin B1? What is it for?
Thiamine, also known as vitamin B1, helps convert the food you eat into the energy you need. Thiamine is important for the growth, development and function of cells in the body.
How much thiamine do I need?
The amount of thiamine needed depends on age and gender. The following are the average recommended amounts per day in milligrams (mg):
| Stage of life | Recommended amount |
| Babies up to 6 months | 0.2 mg |
| Babies 7 to 12 months of age | 0.3 mg |
| Children 1 to 3 years old | 0.5 mg |
| Children 4-8 years old | 0.6 mg |
| Children 9 to 13 years old | 0.9 mg |
| Male adolescents between 14 and 18 years of age | 1.2 mg |
| Female adolescents between 14 and 18 years of age | 1.0 mg |
| Men | 1.2 mg |
| Women | 1.1 mg |
| Pregnant women and adolescents | 1.4 mg |
| Women and adolescents who are breastfeeding | 1.4 mg |
What foods are a source of thiamine?
Thiamine is naturally present in many foods and is added to certain fortified foods. You can get the recommended amounts of thiamine by eating a variety of foods, including:
- whole grain products and fortified foods such as bread, cereals, pasta and rice
- meat (especially pork) and fish
- legumes (such as black beans and soybeans), seeds, and nuts
What types of thiamine dietary supplements are there?
Thiamine is found in multivitamin / multimineral supplements, vitamin B complex dietary supplements, and supplements that only contain thiamine. Common presentations of thiamine in dietary supplements are thiamine mononitrate and thiamine hydrochloride. Some supplements use a synthetic form of thiamine called benfotiamine.
Is the thiamine I consume enough?
In the United States, most people get enough thiamine from the food they eat. Thiamine deficiency is rare in the United States. However, some people have more trouble getting enough thiamine than others:
- people with alcohol dependence
- older people
- people with HIV / AIDS
- people with diabetes
- people who have had bariatric surgery
Talk to your doctor about thiamine and other dietary supplements to determine which supplements, if any, might be of benefit to you.
What happens if I don’t get enough thiamine?
If you don’t get enough thiamine from the foods you eat, or if your body absorbs too much or too little thiamine, you could develop thiamine deficiency.
Thiamine deficiency can cause loss of weight and appetite, confusion, memory loss, muscle weakness, and heart problems. Severe thiamine deficiency causes a condition called “beriberi” that also produces additional symptoms such as tingling and numbness in the hands and feet, muscle loss, and poor reflexes. Beriberi is not a common disease in the United States or other developed countries.
A more common example of thiamine deficiency in the United States is Wernicke-Korsakoff syndrome, which primarily affects people with alcoholism. It causes tingling and numbness in the hands and feet, severe memory loss, disorientation, and confusion.
What are some of the health effects of thiamine?
Scientists study thiamine to better understand how it affects health. Here are some examples of the results of these investigations:
Diabetes
People with diabetes often have low levels of thiamine in their blood. Scientists are studying whether thiamine supplements could improve blood sugar levels and glucose tolerance in people with type 2 diabetes. They are also examining whether benfotiamine supplements (a synthetic form of thiamine) help repair nerve damage caused by diabetes.
Heart failure
Many people with heart failure have low levels of thiamine. Scientists are looking at whether thiamine supplements help people with heart failure.
Alzheimer’s disease
Scientists are studying the possibility that thiamine deficiency plays a role in Alzheimer’s disease dementia. More studies are needed to determine whether thiamine supplements promote mental function in people with Alzheimer’s disease.
Can thiamine be harmful?
Thiamine has not been shown to cause any harm.
Are there interactions with thiamine that I should be aware of?
Yes. Some medications lower thiamine levels in the body. Some examples are:
- Furosemide (Lasix®), used to treat high blood pressure and swelling caused by fluid retention in the body.
- Fluorouracil (5-fluorouracil and Adrucil®), used in chemotherapy treatments for certain types of cancer.
Talk to your doctor, pharmacist, and other health professionals about the dietary supplements and medications (prescription and non-prescription) you take. They will tell you if these dietary supplements could interact or interfere with your medications, or if the medications could interfere with the way your body absorbs, uses, or metabolizes nutrients like thiamine.
Thiamine and healthy eating
According to the federal government’s Dietary Guidelines for Americans , people should get most of their nutrients from food. Food contains vitamins, minerals, dietary fibers and other substances beneficial to health. In some cases, consuming fortified foods and dietary supplements could provide nutrients that would not otherwise be consumed in the minimum recommended amounts. For more information on ways to maintain a healthy diet, see Dietary Guidelines for Americans and the Department’s food guidance system. United States Department of Agriculture, MyPlato.
The information in this fact sheet from the Office of Dietary Supplements (ODS) is in no way a substitute for medical advice. We recommend that you consult your healthcare professionals (doctor, registered dietitian, pharmacist, etc.) if you have any interest or questions about the use of dietary supplements, and what might be better for your overall health. Any mention in this publication of a specific product or service, or recommendation of a professional organization or society, does not represent ODS endorsement of that product, service, or expert advice.
