Vitamin B1

Vitamin B1 Introduction

‘Water-Soluble B’ is a term created by scientists in the early 1900’s, used to describe the chemical substance that prevented/cured the disease of beriberi. Today, Americans are now very familiar with the group of compounds known as B vitamins. The family of B-vitamin compounds is quite multifaceted; scientists often reference these nutrients as the “B-complex” vitamins. “In general, these individual B vitamins each come from food and attach to their own specific proteins made in [various cells in the body], then become enzymes that carry out a variety of crucial metabolic function.” [1] All B vitamins are water-soluble and there are eight of these vitamins in all; they are:

Vitamin B1 was the first in the family of B vitamins to be discovered. In 1912, unknown to scientists at the time, thiamine (B1) was the B-vitamin responsible for thwarting onset of beriberi in humans. Thiamine is well absorbed, but because of its water-solubility, Vitamin B1 must be supplemented in the diet on a daily basis. Those particularly at risk at thiamine deficiencies are alcoholics, chronic dieters, or individuals who are suffering from malnutrition. [2] As with all nutrients, one’s intake, absorption, and daily need, all play an instrumental part in the overall development of a vitamin deficiency.

Vitamin B1 Food Sources

Although found in the majority of both plant and animal sources, thiamine from food is not very plentiful. Very few foods contain an abundant amount of this particular B vitamin.

Food (both plant and animal sources)MeasureMg of thiamin
Brewers yeast 1 oz: 28g 4.37
Sunflower seeds dried 1 cup:144g 3.30
Sirulina dried 1 pack:100g 2.38
Brazilnuts dried 1 cup: 140g 1.40
Oats 1 cup:156g 1.19
Barley 1 cup:184g 1.19
Sesame seeds whole, dried 1 cup:144g 1.14
Pistachio nuts dried 1 cup:128g 1.05
Chicory raw 1 head:513g 1.03
Peanuts raw 1 cup:146g 0.93
Pecans dried 1 cup:108g 0.92
Sausages meatless 1 patty:38g 0.89
Millet raw 1 cup:200g 0.84
Wheat durum 1 cup:192g 0.80
Rice brown, medium grain, raw 1 cup:190g 0.78
Peas green, frozen 1 pack:284g 0.73
Cabbage cooked 1 head: 1262g 0.72
Soy flour defatted 1 cup:100g 0.70
Bakers yeast dry 1 oz:28g 0.65
Spaghetti in tomato sauce w/cheese, canned 1 can: 432g 0.60
Sausage meatless 1 sausage:25g 0.59
Hazelnuts dried 1 cup:115g 0.58
Peas and carrots frozen 1 pack:284g 0.54
Pumpkin and squash seeds roasted 1 cup:227g 0.48
Peas green cooked 1 cup:160g 0.41
Soy milk fluid 1 cup:240g 0.39
Split peas cooked 1 cup:196g 0.37
Toast white bread 1 slice:22g 0.37
Breakfast cereals e.g. corn flakes 1 serving 36.9g 0.37
Tahini 1 tbsp:28.4 0.36
Molasses third extraction or blackstrap 1 cup:328g 0.36
Hummus 1 cup:246g 0.36
Pine nuts dried 1 oz:28.4g 0.35
Peanut butter 1 cup:258g 0.35
Chestnuts 1 cup:143g 0.35
Vegetables mixed, frozen 1 pack:284g 0.35
Quinoa 1 cup:170g 0.34
Lentils 1 serving:198g 0.33
Pinto beans 1 serving:171g 0.32
Couscous dry 1 cup:184g 0.30
Brussel sprouts frozen 1 pacK:284g 0.30
Bean sprouts mung 1 pack: 340g 0.29
Kindney beans cooked 1 serving:177g 0.28
Natto 1 serving: 175g 0.28
Spagehetti whole-wheat, dry 1 serving: 57g 0.28
Miso 1 cup:275g 0.27
Soya beans 1 serving:172g 0.27
Adzuki beans cooked 1 serving:230g 0.26
Tempeh 1 serving:166g 0.22
Potatoes baked 1 potato:202g 0.22


Thiaminase is the B1 enzyme found in raw fish, like sushi. It is important to note that tea, bracken fern, baking soda, and heat all destroy or inactivate thiamine due to its relative instability.

Vitamin B1 Uses

The primary responsibility of thiamine is the conversion of carbohydrates into energy and fat. Vitamin B1 is equally vital in the complicated processes of converting the fatty acids we consume into proteins and enzymes; both of which enhance our ability to digest certain foods. These characteristics may explain the increased effectiveness of thiamine supplementation in diabetes patients.

Thiamine pyrophosphate (TPP) is the coenzyme used in specific biochemical reactions, enabling energy processes to begin in our bodies for daily muscle and brain activity. TPP is also necessary for our brain’s ability to transmit nerve impulses. In fact acetylcholine, a neurotransmitter needed for proper nervous system functioning, is dependant upon thiamine pyrophosphate for its development. [4]

Clinical application with the supplementary thiamine has been promising. Thiamine supplementation has proved beneficial in those suffering from an array of neurological and psychiatric conditions. [5] These conditions include and are not limited to; sciatica, Bell’s Palsy, and also insomnia. As well, the overall health of those who suffer Alzheimer's disease may also be positively influenced by this nutrient. [6]

Vitamin B1 Dosages

The RDA was revised in 1998 for the supplementation of Thiamine and is directly related to energy intake. RDA and DRI defined for Thiamine:

Ages 19-30 1.2mg/day 1.1mg/ day

Although not defined, increases in thiamine are needed in times of pregnancy, lactation, hyperthyroidism, sever body burns, cardiac arrest, and fever/flu.

Vitamin B1 Toxicities and Deficiencies

Vitamin B1 Toxicities

Thiamine is not known to be toxic, since the majority of excesses of this vitamin are excreted in the urine. Thiamine is associated with a certain “medicinal smell” which protrudes from persons ingesting excessive amounts.

Vitamin B1 Deficiencies

Vitamin B1 deficiencies are characterized by anemia, loss of appetite, nausea, fatigue, mental confusion, difficulties in breathing, and constipation. [7] Symptoms may also include; muscular atrophy, paralysis, and muscle spasms of the lower extremities. [1] The abovementioned disease of beriberi is also associated with thiamine deficiency. This disease causes poor posture, lack of equilibrium, and numbness of the lower extremities. Beriberi is very rare in the United States due to the enrichment processes of rice products.


1. Herbert, Victor. “Vitamins and Minerals Plus Antioxidant Supplements” Total Nutrition Ed. Victor Herbert, M.D., Genell J. Subak-Sharpe, M.S. New York: Saint Martin’s Griffin, 1995. 94-118.

2. Heap LC, Pratt OE, Ward RJ, et al. Individual susceptibility to Wernicke-Korsakoff syndrome and alcoholism-induced cognitive deficit: impaired thiamine utilization found in alcoholics and alcohol abusers. Psychiatr Genet. Dec2002;12(4):217-24.

3. Diet and Nutrition, Internet Health Library. Vitamin B1 Tables. Best Sources of Thiamine. March 28, 2001. tables.htm

4. Herbert, Victor. “Vitamins and Minerals Plus Antioxidant Supplements” Total Nutrition Ed. Victor Herbert, M.D., Genell J. Subak-Sharpe, M.S. New York: Saint Martin’s Griffin, 1995. 94-118

5. Carney MW. Vitamin Deficiency and Mental Symptoms. Br J Psychiatry. Jun1990;156:878-82.

6. Mimori Y, et al. Thiamine Therapy in Alzheimer’s Disease. Metab Brain Dis. Mar1996;11(1):89-94.

7. Boros LG, Steinkamp MP, Fleming JC, Lee WN, Cascante M, Neufeld EJ. Defective RNA ribose synthesis in fibroblasts from patients with thiamine-responsive megaloblastic anemia (TRMA). Blood. Jul2003. [Epub ahead of print].