Vitamin B1, which is frequently called thiamine, is part of the B complex of water-soluble vitamins required for proper nutrition. Because vitamin B1 is water soluble, taking too much of it means the excess is flushed from the body in urine. As a result, overdosing on vitamin B1 is extremely rare. However, vitamin B1 may cause side effects, even when taken at low doses. As with any health supplement, you should consult your doctor before taking vitamin B1. One reported symptom of taking too much vitamin B1 is an upset stomach. Breaking one large dose up into several smaller doses and spreading those throughout the day may reduce the risk of stomach upset. Taking vitamin B1 with food may also help. In rare cases, vitamin B1 supplements can cause an allergic reaction. The most common symptom of an allergic reaction is skin irritation resulting in dry, itchy skin or a rash. Also in rare cases, a more severe reaction may occur, resulting in nausea, dizziness, shortness of breath and swelling of the hands, face, mouth or throat.
If you or someone you know experiences severe swelling of the face and has difficulty breathing, contact emergency medical services immediately. The B vitamins all work together in a complex. Taking too much of a single B vitamin, such as vitamin B1, can cause an imbalance in the other B vitamins. In severe cases, the imbalance may cause deficiencies in the other B vitamins, which can cause a wide variety of symptoms. Deficiencies in several of the other B vitamins, such as B3, B6 and B12, can cause feelings of fatigue and tiredness, along with skin irritations and rashes. Deficiencies in B6 and B12 can lead to anemia, causing very pale skin and muscle weakness. Vitamin B12 deficiencies can also cause neurological symptoms, including numbness or tingling in the hands or feet. The Recommended Daily Allowance, or RDA, of vitamin B1 for adults over the age of 19 is 1.2 mg per day for males and 1.1 mg per day for females. The doses for children and infants are smaller, down to 0.2 mg per day for infants younger than 6 months old.
People with vitamin B1 deficiency may be prescribed larger doses to treat their condition. Vitamin supplements often contain 50 to 100 mg of vitamin B1. Because vitamin B1 is generally nontoxic, these doses are almost always safe. Are High Doses of Vitamin B6 Really Dangerous? Side Effects of Extra B-Complex Vitamins Can You Take Multivitamins With B-Complex Vitamins? What If My Child Ate Too Many Vitamins? Can Too Much Vitamin C Hurt the Liver? Can Too Much Vitamin B Cause Tingling? A List of Fat-Soluble Vitamins Characteristics of Water-Soluble Vitamins What Are the Symptoms of Too Much Vitamin D or C? The Side Effects of Thiamine Mononitrate The Effect of Vitamin Supplements on Urine Vitamin C & Gas Dietary Nutritional Supplements That Cause Cloudy Urine What Are the Benefits of Vitamin B-1 or Thiamine? Disadvantages of Vitamin C Is Too Much Niacin Bad for You?Stay Connected With Dr. Weil - Get Free Newsletters Right In Your Inbox
Vitamin B complex supplements are a combination of all the B vitamins. These include vitamin B1, or thiamin; vitamin B2, or riboflavin; vitamin B3 or niacin; vitamin B5, or panthothenic acid; vitamin B6, or pyridoxine; vitamin B7, or biotin; vitamin B9, which is folate or folic acid; and vitamin B12, or cobalamin. B vitamins are soluble in water, so excess amounts will not build up in the body, but be excreted through urine. However, large doses of some B-complex vitamins can still cause side effects and health risks. If a blood test shows that you are not deficient in B vitamins, you do not need to supplement with vitamin B complex. If you are deficient, the health risks can be serious. B vitamins are required for basic bodily functions, such as turning food into usable energy and creating red blood cells. Vitamin B complex supplements, taken under the supervision of a doctor, can treat your deficiency and complications associated with it, such as anemia and fatigue. Some people experience diarrhea, gas and nausea from taking normal doses of vitamin B complex supplements.
If you experience excessive itching, hives, swelling, tingling or difficulty breathing, you may be having an allergic reaction and need medical attention. If you've taken too much vitamin B complex, some symptoms you may experience include blurry vision, nausea and vomiting, numbness, high blood sugar, liver problems and skin lesions. Change in urine color to a fluorescent yellow is a normal and harmless side effect of vitamin B complex. If you experience any uncomfortable side effects, see your doctor. Certain foods are fortified with B vitamins, including breads and cereals. If you're taking tablets that provide 100 percent of your daily recommended intake of B vitamins, you may want to eat fortified foods in moderation -- and watch out for side effects. B vitamins interact with certain medications, so consult with your doctor before taking them if you're on any prescription or over-the-counter medicine. Taking one vitamin B complex tablet a day is not likely to cause toxicity, so you don't have to worry as long as you don't take more than the dosage recommended on the product label.
For example, the upper safety limit for vitamin B3 is 35 milligrams daily. If you take a tablet that provides 100 percent of your daily requirement of vitamin B3, which is 16 milligrams, you would be pushing toward the upper limit with 2 tablets. Be sure to see your doctor before choosing a vitamin B complex supplement to make sure it's right for you. B-Complex Vitamin Benefits & Side Effects Vitamin B1 Overdose Symptoms What Are the Benefits of B Complex Capsules? How to Lose Leg Fat in Thirty Days What Are the Side Effects of Super B Complex? Foods That Are High in B Vitamins Foods Rich in Vitamins B & C Benefits of Vitamin B100 ComplexMeat and eggs are top sources of B vitamins. Vitamin B1, vitamin B2 and vitamin B6 all help your body make energy from the foods that you eat. The vitamins are present in meat, seafood, eggs, milk and cheese. If you eat a balanced diet, you probably get all of the vitamin B1, B2 and B6 that you need. Certain vitamins can cause health problems if you consume too much, and knowing how much is too much can help you prevent an overdose.
Vitamin B1 Vitamin B1, also called thiamin, keeps your heart, muscles and nervous system working the way they're supposed to. It also provides energy to your brain. Adult women need 1.1 milligrams of vitamin B1 each day, and adult men should have 1.2 milligrams. Vitamin B1 is a water-soluble vitamin, which means that if you take in more than you need, you'll excrete the excess in your urine. Because your body gets rid of what you don't need, it is highly unlikely that you'll take in too much vitamin B1, and there no known risk of poisoning connected to the vitamin. Vitamin B2 Vitamin B2, also called riboflavin, plays a role in normal growth and the production of red blood cells. The daily requirement of vitamin B2 is 1.1 milligrams for women and 1.3 milligrams for men. Vitamin B2 is a water-soluble vitamin, so your body doesn't store excess amounts. Instead, any vitamin B2 that you consume that your body doesn't use is excreted in your urine. Because your body doesn't hold onto vitamin B2, there isn't an upper limit recommended for safety.
Vitamin B2 has not been known to cause poisoning. Vitamin B6 Vitamin B6, also a water-soluble vitamin, helps your body metabolize protein and fats. The daily recommended intake of vitamin B6 is 1.3 milligrams for adults between the ages of 18 and 50. After age 50, men need 1.7 milligrams a day and women need 1.5 milligrams. According to the National Institutes of Health, consuming too much B6 from food is unlikely. However, too much vitamin B6 in supplement form can cause adverse reactions. An excess of vitamin B6 can cause sensory neuropathy. It can also cause painful skin lesions, gastrointestinal problems, nausea and heartburn. Typically, the symptoms disappear if an individual stops taking the supplement. The upper limit for vitamin B6 intake is 100 milligrams per day. Considerations You probably get plenty of vitamins B1, B2 and B6 from your diet, but if you suspect that you're deficient, talk with your doctor. You might benefit from a supplement. Don't take a vitamin supplement, especially a vitamin B6 supplement, without asking your doctor, however, because it's far easier to consume too much from a tablet or vitamin than from the foods you eat.