Thiamin (B1) DESCRIPTION: Thiamin is also known as vitamin B1 and was first isolated from rice polishings in 1926.   STABILITY Thiamin is one of the vitamins most easily attacked by environmental conditions. It is water-soluble and is lost by leaching into cooking water or dripping from thawed frozen foods. It is also destroyed rapidly by alkalis (e.g. bicarbonate of soda) and ultra violet light. Additionally, the preservative Sulphur dioxide destroys thiamin.   FUNCTIONS Thiamin functions in the body as part of the coenzyme thiamin pyrophosphate. This coenzyme is vital for the release of energy from carbohydrates, fats and alcohol. DEFICIENCY A severe deficiency of thiamin is now rarely seen in the West, but extremely low intakes lead to a condition known as beri-beri, which is fatal if not quickly treated with thiamin. Symptoms of beri-beri are muscle weakness, nausea, a loss of appetite and Water Retention leading to heart and lung damage. Minor thiamin deficiencies are known to cause mental conditions such as Depression, irritability, lack of concentration and memory loss. Loss of weight and gastrointestinal upsets are also noted. Back to Top   REQUIREMENTS Upper safe level for daily supplementation = 100mg Recommended Daily Allowance = 1.4mg Back to Top   SUPPLEMENTAL USES Thiamin may be taken in supplement form to guard against any possibility of a deficiency. Factors that increase the need for thiamin are:   High carbohydrate intake High alcohol intake (1) Physical or mental Stress (2) Insect Repellant: Some individuals appear to find thiamin effective as an insect repellant. Controlled trials are required to confirm this (1). Mood Enhancer: Thiamin supplementation has been shown to improve mood, making people feel more composed, energetic and clear-headed compared to those not taking the supplements (3). Back to Top   SAFETY Long term oral intakes of up to 3000 mg/day have not caused undesirable side effects in adults. Back to Top   INTERACTIONS AND CONTRA-INDICATIONS There are no contra-indications recorded for thiamin. Back to Top   FOOD SOURCES Food (mg/100g) Yeast extract 3.1 Fortified breakfast cereal 1.8 Soya beans, dry 1.1 Pork chop 0.57 Rice 0.41 Bread, wholemeal 0.34 Peas, frozen 0.32 Peanuts, roasted 0.23 Bread, white 0.21 Potatoes 0.2 Chicken 0.11 Beef, stewing steak 0.06 Milk 0.05 The main sources of thiamin in the diet are bread and cereal products, potatoes, milk and meat. REFERENCES: 1. "Handbook of Dietary Supplements", Pamela Mason, Blackwell Science, 1995. 2. Romero IA, et al. Early metabolic changes during m-Dinitrobenzene neurotoxicity and the possible role of oxidative stress. Free Radical Biol Med,18;2:311-319, 1995. 3. Benton D, Griffiths R, Haller J. Thiamine supplementation mood and cognitive functioning. Psychopharmacology, 129:66-71, 1997. Back to Top   Related News Stories   Psychology and Nutrition Certain nutrients are linked to emotional well being.   Alcohol consumption, micronutrients and colorectal cancer A study assessed the relation between alcohol and micronutrients that have protective properties against colorectal cancer. Back to Top