What Is Vitamin B1?
You may have heard of the different B vitamins that your body needs to function properly. There are eight of them. Some we know better by their number, like vitamin B12. Others, such as B1, we know better by their name, thiamine. Like the other B vitamins, B1 is an essential nutrient that’s important in helping your body’s cells grow, develop, and function. You can get vitamin B1 from many foods or over-the-counter (OTC) supplements if needed.
Vitamin B1 is a water-soluble vitamin, which means it dissolves in water and can’t be stored in your body. You need to be sure to take in enough of the vitamin every day.
Vitamin B1 Benefits
Vitamin B1 has several benefits including boosting energy production. Vitamin B1 helps break down the food you eat and converts it into energy. In particular, it breaks down carbohydrates.
Vitamin B1 also might:
Help fight depression. Taking vitamin B1 supplements along with an antidepressant may be good for managing depression. Vitamin B1 may help ease symptoms faster while stabilizing your mood. A small study in China found that older people with depression also had low vitamin B1 levels.
Help you manage diabetes. If you have diabetes, you might want to talk to your doctor about getting more vitamin B. Some small studies show that high blood sugar and insulin levels improve for some patients after they take vitamin B1 regularly. It may also reduce high blood pressure and heart complications in people with diabetes.
Reduce the risk of kidney and circulation problems. Vitamins B1 and B12 may help improve nerve pain in people with diabetes, reducing the need for painkillers.
Minimize the risk of heart disease. Thiamine is key to the production of acetylcholine — the element that helps your body pass messages between nerves and muscles. Without this communication, your heart wouldn’t work the way it should. Chronic lack of vitamin B1 is one possible reason for irregular cardiac function.
Improve memory. Getting enough thiamine might help improve concentration and memory in some people. Because of its possible positive effect on attitude and brain function, it is also known as a "morale vitamin."
Thiamine is also given to people who are hospitalized for alcohol withdrawal to try to prevent a condition called Wernicke encephalopathy. This can lead to Wernicke-Korsakoff syndrome.
Children with a rare condition called maple syrup disease or congenital lactic acidosis may need thiamine as part of their treatment.
Early studies
Alzheimer’s disease. Researchers are working on animal trials to study how vitamin B1 might help people with Alzheimer’s disease. The focus is on whether B1 supplements may help prevent memory loss and dementia in people who have changes in their brain (deposits) but don’t yet have dementia. The trials are still in the early stages though. One of the drawbacks of vitamin B1 is that older people don’t absorb it well, so more research is needed.
Cataracts. Some early study results show that vitamin B1, along with some other vitamins, might lower the risk of developing cataracts.
Vitamin B1 Deficiency Risk Factors
It’s not that easy to become vitamin B1-deficient in the U.S. because the main cause is lack of vitamin B1 in yourdiet. Other risk factors for vitamin B1 deficiency include:
- Alcoholism
- Using parental nutrition (special liquid preparations delivered through a central line)
- Being pregnant
- Having had bariatric surgery
- Being on chronic diuretic (water pill) therapy
Symptoms of Vitamin B1 Deficiency
A lack of vitamin B1 can lead to serious health consequences. Early symptoms include:
- Headache
- Fatigue
- Irritability
- Depression
- Abdominal discomfort
Very low thiamine levels may lead to:
- Beriberi, a condition that causes a loss of appetite, muscle weakness, and a pricking feeling in the toes and burning in the feet
- Fast heartbeat, low blood pressure (hypotension), and fluid retention
Low levels of B1 can cause a condition called Wernicke-Korsakoff syndrome. Low levels of vitamin B1 in people who consume large amounts of alcohol can cause:
Sources of Vitamin B1
The best way to get vitamin B1 is through your diet. This way, vitamin B1 is also combined with other vitamins and nutrients that you need to keep your body functioning. Keep in mind that how you prepare your food can have an impact on how much B1 remains though. For example, one study showed:
- Boiling some vegetables can cause them to lose as much as 22% of the vitamin if you keep the cooking water and up to 35% if you toss it. B1 is water soluble, which is why so much can be lost.
- Roasting pork loin can cause up to 43% of thiamine loss. You would lose a lot less if you braised the pork instead.
- Using a double boiler to cook whole-grain cereals doesn’t destroy vitamin B1.
- Baking bread causes the grain to lose around 15% of thiamine.
Some of the most common foods that have vitamin B1 include:
- Wheat germ
- Legumes, such as beans
- Beef
- Organ meats
- Pork
- Poultry
- Whole-grain cereals
- Nuts
- Bran
- Potatoes
- Brewer's yeast
- Blackstrap molasses
- Rice
- Fish, such as trout and tuna
- Vegetables, such as green peas and acorn squash
- Yogurt
- Oranges and orange juice
Some breakfast cereals, breads, and baby formulas are also fortified.
Vitamin B1 supplements
It’s always best to get vitamins and nutrients through food sources. However, if you can’t get enough vitamin B1 from your diet or your blood B1 levels are low, your doctor might suggest that you take a supplement. If you have symptoms of low B1, it can take a few weeks before they go away.
Vitamin B1 is available in most multivitamin/mineral OTC products, which is typically what doctors recommend. You can get B1 alone, but the worry is that if you take just vitamin B1 over a long period, the other B vitamins might not be balanced. The only supplements for vitamin B1 are thiamine mononitrate and thiamine hydrochloride. Your body uses B1 as you take them. Another option is benfotiamine, which is a thiamin derivative. Your body has to convert it into vitamin B1 to work.
If you are taking vitamin B1 supplements:
- Take them as prescribed or listed on the label.
- Tell all your doctors and specialists that you're taking it in case it works against the medications they want to prescribe. These are some drugs that might interact with vitamin B1:
- Check with your pharmacist before taking other supplements or natural products to make sure it’s safe to take with vitamin B1.
- Tell your doctor if you are pregnant, plan on becoming pregnant, or are breastfeeding.
- If you take thiamine regularly and become pregnant, tell your doctor.
Vitamin B1 Dosage for Adults
If your blood tests don’t show vitamin B1 deficiency and you don’t take any supplements, you are getting enough of the vitamin through your daily diet. However, if your B1 blood levels are low and you do need to take supplements, these are the recommended daily allowances (RDA):
- Men over 19: 1.2 milligrams per day
- Women over 19: 1.1 milligrams per day
- Someone who is pregnant or breastfeeding: 1.4 milligrams per day
Check with your doctor to see if this is right for you or if you need a different dose.
Taking too much of any vitamin or mineral is never a good idea, although there doesn’t seem to be an upper limit of vitamin B1 that would cause problems. Since vitamin B1 is water soluble, it doesn’t stay in your body and you pee out what your body doesn’t need.
Vitamin B1 Side Effects
If you are taking vitamin B1 supplements, you could experience some side effects. They include:
- Flushing (sudden redness, usually on the upper chest, neck, or face)
- Hives
- Itchy skin
- Sweating
- Nausea
- Restlessness
If the symptoms don’t go away or they’re severe, speak with your doctor as soon as possible.
You should limit or stop drinking alcohol altogether while taking vitamin B1 because excess alcohol can prevent your body from absorbing the vitamin as it should.
Takeaways
Vitamin B1 is a readily available nutrient found in many of the foods we eat. If you do have a B1 deficiency, your doctor might recommend that you take a supplement to help raise the amount in your blood. Drinking too much alcohol could affect how vitamin B1 is absorbed in your body, so it’s best to limit or cut out alcohol if you are taking B1 supplements.
Vitamin B1 FAQs
Can you take too much vitamin B1?
Researchers haven’t found an upper limit of B1 that could be toxic. However, taking more than the recommended amount won’t do any good as your body takes what it needs and gets rid of the rest.
What conditions cause vitamin B1 deficiency?
Not many conditions cause vitamin B1 deficiency. Around the world, the most common cause is not having enough vitamin B1 in the diet. Other causes include:
- Alcoholism
- Using parental nutrition (special liquid preparations delivered through a central line)
- Being pregnant
- Having had bariatric surgery
- Being on chronic diuretic (water pill) therapy
Is it OK to take vitamin B1 daily?
If you don’t need to take a vitamin B1 supplement, you shouldn’t because it won’t do your body any good. You will just eliminate what you don’t need. However, if your doctor says you do need a supplement, you usually need to take it every day.
Who needs vitamin B1 the most?
Everyone needs vitamin B1 and there’s no specific group that needs it more than others.