Vitamin B1 – Thiamin – What Is It?

Vitamin B1 is also known as thiamine or thiamin. Thiamin is a water-soluble vitamin that acts as a coenzyme in many metabolic pathways in the body. The word is derived from “thio” meaning sulfur and “amine” meaning nitrogen-containing.  Therefore, the compound contains one sulfur and a few nitrogen atoms.  In today’s language, we’ve dropped the “e” at the end, so the spelling is now thiamin.

Thiamin is absorbed in the small intestine and transported around the body in red blood cells. The body doesn’t store very much of this vitamin, but what is stored is found in the muscles and liver.  The half-life of thiamin is only 9-18 days, so it doesn’t take a long time for a person to exhaust his or her store of this vitamin and show signs of a deficiency.  On the other hand, like most water-soluble vitamins, any excess intake is excreted in urine.

What Does It Do?

Thiamin is involved in energy synthesis and the metabolism of carbohydrates and certain branched-chain amino acids (leucine, isoleucine, and valine).  Thiamin has a role in nerve function by synthesizing neurotransmitters.  It also involved in the conduction of nerve impulses.

Where Can You Find It?

vitamin-b1-sourceSmall quantities of thiamin are found in a wide variety of foods.  Sources high in thiamin include Brewer’s yeast, pork, wheat germ, acorn squash, soy milk, fortified cereals, watermelon, and fresh-squeezed orange juice.  It can also be found in smaller quantities in sunflower seeds, legumes, whole and enriched grains, asparagus, organ meats, peanuts, and mushrooms.

How Much Do You Need?

The RDA for thiamin is shown below:

Group                                              Recommended nutrient daily intake
Infants and children
0-6 months                                                                0.2 mg
7-12 months                                                              0.3 mg
1-3 years                                                                    0.5 mg
4-6 years                                                                    0.6 mg
7-9 years                                                                    0.9 mg
Adolescents, 10-18 years
Females                                                                      1.1 mg
Males                                                                          1.2 mg
Females, 19+ years                                                  1.1 mg
Males, 19+ years                                                      1.2 mg
Pregnancy                                                                 1.4 mg
Lactation                                                                   1.5 mg

What Happens If You Don’t Get Enough?

BeriberiA well-known thiamin deficiency disease is beriberi, which mostly affects populations who eat a lot of polished rice.  Because thiamin is involved in energy metabolism, a deficiency of this vitamin affects every organ in the body.  There are two types of beriberi – wet and dry.  Wet beriberi affects the cardiovascular system.  Symptoms include a fast heart rate (tachycardia), shortness of breath (dyspnea), and swelling in the lower legs, all of which can progress into congestive heart failure.  Dry beriberi affects the nervous system, which can lead to difficulties in walking, loss of muscle function, paralysis, and mental confusion.

The most common condition of thiamin deficiency is Wernicke’s encephalopathy, which is characterized by a lack of voluntary muscle control (ataxia), voluntary or involuntary eye movement (nystagmus), double vision, mental confusion, and general disorientation.  Korsakoff syndrome is another thiamin deficiency disease which is characterized by impaired memory, the inability to form new memories, and hallucinations.

Thiamin deficiency is also a concern for people who have had bariatric weight-loss surgery.  Post-surgical complications include nausea and vomiting, which can lead to a deficiency of this important vitamin.

What Happens If You Take Too Much?

Current research suggests that there are no adverse effects from the intake of too much thiamin. Since it is a water-soluble vitamin, excess amounts are excreted in urine. Therefore, there is no Upper Tolerable Limit for thiamin.

Bottom Line

The best way to consume any nutrient in order to avoid under-consumption is to consume a wide variety of foods, in a wide variety of colors, and eat according to MyPlate.

Until next time, remember that… there are no excuses when it comes to your health!


4 thoughts on “Vitamin B1 – Thiamin – What Is It?

  1. Pingback: An Overview of the B5 Vitamin

  2. This is one of the most intelligent blog posts I have seen in a long while. Your content is rich and you get straight to the point. Have you considered charging people for your valuable experience and insight?

    • Honestly, no I haven’t! We started this blog to help people, and hopefully that’s what we do. I’ve noticed that this particular blog post gets a lot of hits for people looking for information on beriberi. If we can help people understand what causes this terrible disease so they don’t ever get it, we feel like we’ve accomplished our mission 🙂

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