Learn all about Vitamin B1 (Thiamine)
What is Vitamin B1 (Thiamine)?
Energise your metabolism with essential vitamin B1. This key nutrient converts food to fuel & supports nervous system health. Boost your vitality!
Benefits of Vitamin B1 (Thiamine)
"Thiamine deficiency represents an often overlooked but significant nutritional issue, even in developed countries. Its effects range from subtle cognitive changes and fatigue to life-threatening conditions. What makes thiamine unique among nutrients is its crucial role at the intersection of energy metabolism and neurological function, explaining why deficiency can manifest so dramatically in both these systems. The rising recognition of subclinical deficiency states highlights the importance of adequate thiamine for optimal health beyond simply preventing beriberi."
- Dr Lucien Armstrong, PhD in Nutritional Biochemistry, University College London (source)
How to use Vitamin B1 (Thiamine)
Dosage
Men: 1.2mg daily; Women: 1.1mg daily; increased needs during pregnancy (1.4mg) and lactation (1.5mg)
Timing
Can be taken with or without food; spreading intake throughout the day may optimise absorption
Notes
Thiamine hydrochloride and thiamine mononitrate are common supplement forms; benfotiamine (fat-soluble derivative) may offer superior bioavailability and tissue penetration
Who should take Vitamin B1 (Thiamine)?
- Individuals with high-carbohydrate diets or increased energy requirements
- Those with alcohol dependency or history of alcohol abuse
- People with malabsorption conditions or gastrointestinal disorders
- Older adults at risk of suboptimal nutrient intake
- Individuals experiencing unexplained fatigue or cognitive issues
- Athletes and those with high physical activity levels
How does Vitamin B1 (Thiamine) work?
Thiamine functions primarily after conversion to its active form, thiamine pyrophosphate (TPP), which serves as a crucial cofactor for enzymes involved in carbohydrate metabolism, including pyruvate dehydrogenase and α-ketoglutarate dehydrogenase in the Krebs cycle. It facilitates the decarboxylation of pyruvate and α-ketoglutarate, enabling energy production through the citric acid cycle. Additionally, thiamine supports transketolase in the pentose phosphate pathway, which generates NADPH and ribose-5-phosphate for fatty acid and nucleic acid synthesis. In neural tissue, thiamine contributes to acetylcholine synthesis and maintains ion gradients necessary for nerve impulse transmission.
Frequently asked questions
Natural sources of Vitamin B1 (Thiamine)
Whole grains (particularly their outer layers and germ) provide significant thiamine, explaining why polished grains can lead to deficiency. Pork is exceptionally rich in thiamine, with other good sources including legumes (beans, lentils), nuts (especially macadamias and pistachios), seeds (sunflower, flax), and fortified foods such as breakfast cereals and bread products. Yeast (brewer's and nutritional) contains substantial levels. Thiamine is water-soluble and heat-sensitive, so food processing, cooking methods, and storage can significantly reduce content.
Potential side effects & risks
Warnings
No established upper limit due to low toxicity risk and efficient excretion of excess. Some individuals may experience allergic reactions to thiamine supplements. Those with certain genetic conditions affecting thiamine metabolism should receive medical guidance regarding supplementation.
Side effects
Generally well-tolerated even at high doses. Rare allergic reactions may occur, particularly with injected forms. Mild gastrointestinal discomfort occasionally reported with very high oral doses.
Interactions
Diuretics, particularly loop diuretics like furosemide, may increase thiamine excretion. Some antibiotics may reduce thiamine absorption or utilisation. Certain foods (tea, coffee, raw fish, and shellfish) contain thiaminases that can degrade thiamine.