Generic Name: thiamine (THYE-a-min)
Medically reviewed by Drugs.com. Last updated on Dec 2, 2020.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Nutritive Agent
Pharmacologic Class: Vitamin B (class)
Uses for thiamine
Vitamins are compounds that you must have for growth and health. They are needed in small amounts only and are usually available in the foods that you eat. Thiamine (vitamin B 1) is needed for the breakdown of carbohydrates.
Some conditions may increase your need for thiamine. These include:
- Diarrhea (continuing)
- Fever (continuing)
- Illness (continuing)
- Intestinal disease
- Liver disease
- Overactive thyroid
- Stress (continuing)
- Surgical removal of stomach
Also, the following groups of people may have a deficiency of thiamine:
- Patients using an artificial kidney (on hemodialysis)
- Individuals who do heavy manual labor on a daily basis
Increased need for thiamine should be determined by your health care professional.
Lack of thiamine may lead to a condition called beriberi. Signs of beriberi include loss of appetite, constipation, muscle weakness, pain or tingling in arms or legs, and possible swelling of feet or lower legs. In addition, if severe, lack of thiamine may cause mental depression, memory problems, weakness, shortness of breath, and fast heartbeat. Your health care professional may treat this by prescribing thiamine for you.
Thiamine may also be used for other conditions as determined by your health care professional.
Claims that thiamine is effective for treatment of skin problems, chronic diarrhea, tiredness, mental problems, multiple sclerosis, nerve problems, and ulcerative colitis (a disease of the intestines), or as an insect repellant or to stimulate appetite have not been proven.
Injectable thiamine is administered only by or under the supervision of your health care professional. Other forms of thiamine are available without a prescription.
Importance of Diet
For good health, it is important that you eat a balanced and varied diet. Follow carefully any diet program your health care professional may recommend. For your specific dietary vitamin and/or mineral needs, ask your health care professional for a list of appropriate foods. If you think that you are not getting enough vitamins and/or minerals in your diet, you may choose to take a dietary supplement.
Thiamine is found in various foods, including cereals (whole-grain and enriched), peas, beans, nuts, and meats (especially pork and beef). Some thiamine in foods is lost with cooking.
Vitamins alone will not take the place of a good diet and will not provide energy. Your body also needs other substances found in food such as protein, minerals, carbohydrates, and fat. Vitamins themselves often cannot work without the presence of other foods.
The daily amount of thiamine needed is defined in several different ways.
- For U.S.—
- Recommended Dietary Allowances (RDAs) are the amount of vitamins and minerals needed to provide for adequate nutrition in most healthy persons. RDAs for a given nutrient may vary depending on a person's age, sex, and physical condition (e.g., pregnancy).
- Daily Values (DVs) are used on food and dietary supplement labels to indicate the percent of the recommended daily amount of each nutrient that a serving provides. DV replaces the previous designation of United States Recommended Daily Allowances (USRDAs).
- For Canada—
- Recommended Nutrient Intakes (RNIs) are used to determine the amounts of vitamins, minerals, and protein needed to provide adequate nutrition and lessen the risk of chronic disease.
Normal daily recommended intakes in milligrams (mg) for thiamine are generally defined as follows:
|Persons||U.S. (mg)||Canada (mg)|
|Infants and children
Birth to 3 years of age
|4 to 6 years of age||0.9||0.7|
|7 to 10 years of age||1||0.8–1|
|Adolescent and adult males||1.2–1.5||0.8–1.3|
|Adolescent and adult females||1–1.1||0.8–0.9|
Before using thiamine
If you are taking this dietary supplement without a prescription, carefully read and follow any precautions on the label. For this supplement, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to thiamine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Problems in children have not been reported with intake of normal daily recommended amounts.
Problems in older adults have not been reported with intake of normal daily recommended amounts. Studies have shown that older adults may have lower blood levels of thiamine than younger adults. Your health care professional may recommend that you take a vitamin supplement that contains thiamine.
Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this dietary supplement, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this dietary supplement with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Proper use of thiamine
The dose of thiamine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of thiamine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage forms (tablets, oral solution):
- To prevent deficiency, the amount taken by mouth is based on normal daily recommended intakes:
- For the U.S.
- Adult and teenage males—1.2 to 1.5 milligrams (mg) per day.
- Adult and teenage females—1 to 1.1 mg per day.
- Pregnant females—1.5 mg per day.
- Breast-feeding females—1.6 mg per day.
- Children 7 to 10 years of age—1 mg per day.
- Children 4 to 6 years of age—0.9 mg per day.
- Children birth to 3 years of age—0.3 to 0.7 mg per day.
- For Canada
- Adult and teenage males—0.8 to 1.3 mg per day.
- Adult and teenage females—0.8 to 0.9 mg per day.
- Pregnant females—0.9 to 1 mg per day.
- Breast-feeding females—1 to 1.2 mg per day.
- Children 7 to 10 years of age—0.8 to 1 mg per day.
- Children 4 to 6 years of age—0.7 mg per day.
- Children birth to 3 years of age—0.3 to 0.6 mg per day.
- To treat deficiency:
- Adults and teenagers—Treatment dose is determined by prescriber for each individual based on the severity of deficiency. The following dosage has been established: Beriberi—Oral, 5 to 10 mg three times a day.
- Children—Treatment dose is determined by prescriber for each individual based on the severity of deficiency. The following dosage has been established: Beriberi—Oral, 10 a day.
- To prevent deficiency, the amount taken by mouth is based on normal daily recommended intakes:
If you miss a dose of thiamine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
If you miss taking a vitamin for 1 or more days there is no cause for concern, since it takes some time for your body to become seriously low in vitamins. However, if your health care professional has recommended that you take this vitamin, try to remember to take it as directed every day.
Store the dietary supplement in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Thiamine side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Rare- Soon after receiving injection only
- difficulty in swallowing
- itching of skin
- swelling of face, lips, or eyelids
- wheezing or difficulty in breathing
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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- Drug class: vitamins
Other brands: Vitamin B1