Vitamin B1 (thiamine)
Vitamin B1 is water-soluble and because it does not get stored in the body we depend on regular intake of the nutrient. In the 1920s, the Japanese scientist Umetaro Suzuki discovered vitamin B1 in rice shells and observed that this nutrient counteracted the classic deficiency symptom beriberi. Vitamin B1 is destroyed by alkaline substances and heating but not by freezing
Functions and importance for
- Energy metabolism and carbohydrate metabolism
- Normal energy levels
- Normal nervous and brain function
- Maintenance of psychological balance
- Normal muscle and heart function
- Production of hydrochloric acid in the stomach and normal digestion
- Antioxidant that protects against free radicals
Deficiencies and poor utilisation may be caused by
- Alcohol abuse that results in poor utilisation of the nutrient due to damaged liver and intestinal function
- Unbalanced diets
- Tannic acid and sulphites
- Overconsumption of coffee and other stimulants
- Overconsumption of sugar and junk-food
- Diuretics, antacids, and contraceptive pills
- Too little gastric juice and poor intestinal flora
- Stomach ulcer and Crohn's Disease
- Stress.
Deficiency symptoms
The most common symptoms caused by minor deficiency:
- Persistent nausea, loss of appetite, and weight loss
- Heart rhythm disorders
- Fatigue, irritability, despair, and insomnia
- Constipation
- Chest tightness
- Tingling sensation in arms, legs, and skin
Symptoms caused by major and persistent deficiency:
Beriberi used to be quite widespread (namely in Asia) as a result of eating polished rice. Beriberi is one of many deficiency diseases. Dry beriberi is mainly seen with alcoholics in our part of the world. Symptoms include nerve infection, loss of muscle strength, and walking disorders.
Wet beriberi causes heart muscle weakening and water retention in the body. Left untreated, this condition may result in heart failure.
Wernicke's encephalopathy is an acute and life-threatening condition that is caused by a vitamin B1 shortage in the brain. The underlying cause is typically long-term alcohol abuse. Amphetamine abusers and users of methylphenidate (medicine for treating ADHD) are also in the risk group. Symptoms include disturbances of consciousness, speech difficulty, walking disorders, and death in worst case.
Korsakoff's syndrome is also caused by a major vitamin B1 shortage in the brain and often as a result of long-term overconsumption of alcohol. Korsakoff's syndrome is often accompanied by Wernicke's encephalopathy and the disease is characterised by permanent damage to the memory. Wernicke's encephalopathy and Korsakoff's syndrome are both treated with injections of large vitamin B1 doses.
Sources
Coarse, green foods and fresh produce. Good sources include whole-grain, rice bran, sunflower seeds, wheat germ, Brazil nuts and other nuts, beans, peas, seeds, and Brewer's yeast. Also, meat, cod roe, and dairy products are good sources
Content of vitamin B1 (thiamine) in mg per 100 grams
| Sunflower seeds | 2.10 |
| Wheat germ | 1.5 |
| Pork/veal, raw | 0.7/0.05 |
| Broccoli | 0.7 |
| Brown rice | 0.48 (polished rice 0.07) |
Recomended daily allowance (RDA)
Adults: 11 years of age and older: 1.1 mg
Children: 1-10 years of age: 0.7 mg
Increased need
- In case of the listed deficiency symptoms and with use of medical drug
- Pregnancy and lactation
- Overconsumption of alcohol, coffee, and other stimulants
- Overconsumption of sugar
- Stress
- Poor intestinal flora and Crohn's Disease
- Antacids and diuretics
- Hard labour and extreme sport
- Long-term disease
Important information
Supplements of vitamin B1 should normally be taken with the other B vitamins and not together with antacids
Overdosing - side effects
No side effects are described in the literature and the human body can handle rather large quantities. Repetitive injections may cause allergic reactions in some cases. As vitamin B1 is water-soluble and any excess is excreted with the urine it is very difficult to overdose without administering the vitamin intravenously.