Nutrition Library
Vitamin B1 (Thiamine)
Brewer's yeast
General Information
  • Vitamin B1 (thiamine) is a water-soluble B vitamin and is essential for the body.
  • Excess vitamin B1 is quickly excreted from the body, so regular intake is necessary.
  • It is very sensitive to heat.
  • In industrialized countries, most people have sufficient thiamine supply. A vitamin B1 deficiency (and corresponding consequences) may occur in the case of alcohol abuse or after bariatric surgery for morbid obesity.
  • Deficiency due to insufficient food variety is fairly common in in areas of food insecurity and restricted food choices.
Why Do We Need Vitamin B1?

As a coenzyme, vitamin B1 is involved in many metabolic reactions. In particular, it plays a central role in carbohydrate metabolism and in the nervous system.

  • Important for a functioning nervous system and formation of neurotransmitters (e.g., acetylcholine)
  • Energy metabolism
  • Carbohydrate and protein metabolism
  • Important for the immune system
Possible Causes of Deficiency

Insufficient intake:

  • Limited variation in the diet, with few foods rich in vitamin B1

Increased intake requirements:

  • Pregnant and nursing mothers
  • Elderly individuals
  • Competitive athletes
  • Fever
  • Stress
  • High tea/coffee consumption (tannins)
  • Hyperthyroidism
  • Depression
  • Heart failure
  • Hemodialysis

Reduced absorption: 

  • Bowel diseases such as Crohn’s disease or celiac disease
  • Bariatric surgery (surgery for obesity)

Increased excretion:

  • Taking diuretics
  • Diabetes mellitus (loss of vitamin B1 due to kidney dysfunction)
  • Alcohol abuse

Interaction with medications:

  • Increased vitamin B1 intake requirements: antiepileptics, cardiac glycosides (e.g., digitoxin), neuroleptics, tricyclic antidepressants
  • Impaired vitamin B1 intake: antacids, antibiotics, laxatives, oral contraceptives
Symptoms of Deficiency
  • General: loss of appetite, depression, poor concentration, irritability, sleep disorders
  • Blood: anemia
  • Heart: heart failure, tachycardia, edema
  • Gastrointestinal: indigestion
  • Neurology: neuropathy (e.g., feet), muscle weakness or even paralysis, dizziness, hallucinations; together, these symptoms are known as Wernicke encephalopathy
Recommended Intakes

Recommended intake for adults and adolescents:

  • D-A-CH: Women 1.0 mg/day, Men 1.1–1.3 mg/day

  • USA Food and Nutrition Board (FNB): Women 1.1 mg/day, Men 1.2 mg/day

Pregnant women:

  • D-A-CH: 1.3 mg/day

  • USA Food and Nutrition Board (FNB): 1.4 mg/day

Breastfeeding women:

  • D-A-CH: 1.3 mg/day

  • USA Food and Nutrition Board (FNB): 1.4 mg/day

Children, depending on age, see:

 

The Best Plant Sources (per 100 g)

Vitamin B1 is quite sensitive to heat. During cooking, up to 70% of the thiamin may be lost. Good vegetarian sources include legumes, potatoes, seeds, and nuts. B1 is found particularly in the outer layers of all types of grain.

  • Brewer’s yeast – 12 mg
  • Yeast flakes – 7.4 mg
  • Rice bran – 2.2 mg
  • Soybean meal – 2.2 mg
  • Sunflower seeds – 1.9 mg
  • Soy flour – 1.5 mg
  • Tahini – 1.3 mg
  • Mushrooms, dried – 1.0 mg
  • Soybeans – 1.0 mg
  • Peanuts – 0.9 mg
  • Pecans – 0.9 mg
  • Sesame – 0.8 mg
  • Pine nuts – 0.8 mg

 

  • Brazil nuts – 0.7 mg
  • Pistachios – 0.7 mg
  • Wheat bran – 0.7 mg
  • Oatmeal – 0.6 mg
  • Kidney beans – 0.6 mg
  • Beans – 0.6 mg
  • Walnuts – 0.5 mg
  • Flaxseed – 0.4 mg
  • Whole grain bread – 0.3 mg
  • Chickpeas – 0.3 mg
  • Peas, green – 0.3 mg
  • Asparagus – 0.2 mg
  • Spinach – 0.2 mg
Sources
  • Biesalski, H.K., Bischoff, S.C., Pirlich, M., Weidmann, A., (2018). Ernährungsmedizin – Nach dem Curriculum Ernährungsmedizin der Bundesärztekammer (5.Auflage). Stuttgart: Georg Thieme Verlag

  • Gröber, U. (2011): Mikronährstoffe. Metabolic Tuning – Prävention – Therapie. 3. Aufl. Wissenschaftliche Verlagsgesellschaft mbH Stuttgart