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