How much Vitamin B1 (Thiamine) should I take daily?
Pro Research Analysisby 
Searched over 200M research papers
Daily Vitamin B1 (Thiamine) Intake Recommendations
Recommended Daily Allowance (RDA) for Thiamine
The Recommended Daily Allowance (RDA) for thiamine, also known as vitamin B1, varies slightly between genders. For adult females, the RDA is 1.1 mg per day, while for adult males, it is 1.2 mg per day1. This recommendation is based on the average dietary intake required to prevent deficiency in the general population.
Thiamine Intake Based on Caloric Consumption
Thiamine requirements are closely linked to caloric intake. It is recommended that individuals consume 0.4 mg of thiamine for every 1,000 kcal consumed2. This means that the more calories you consume, the higher your thiamine requirement will be to support metabolic processes.
Lower and Upper Intake Limits
Clinical signs of thiamine deficiency have been observed at intakes below 0.5 mg/day, which corresponds to 0.05 mg per megajoule (MJ) of energy intake3. To ensure adequate thiamine levels, intakes of 0.07-0.08 mg/MJ are recommended, as these levels have been shown to normalize thiamine excretion and enzyme activity3. There is currently no established upper intake level for thiamine due to a lack of data on potential adverse effects from high doses3.
Special Populations and Increased Requirements
Certain populations may have increased thiamine requirements. For example, pregnant and lactating women may need higher thiamine intake to meet their increased metabolic demands3. Additionally, individuals with chronic conditions such as kidney disease or those undergoing bariatric surgery may also require higher doses of thiamine to prevent deficiency5.
High-Dose Thiamine Supplementation
In some cases, high-dose thiamine supplementation may be beneficial. For instance, high doses of thiamine (100 mg/day) have been shown to help prevent exercise-induced fatigue and improve recovery in athletes6. Similarly, high-dose parenteral thiamine (500 mg three times per day) is often used to treat Wernicke's encephalopathy, a severe neurological condition caused by thiamine deficiency5.
Conclusion
The daily intake of thiamine should be tailored to individual needs based on caloric intake and specific health conditions. While the general RDA is 1.1-1.2 mg for adults, higher doses may be necessary for certain populations or under specific conditions. Always consult with a healthcare provider before making significant changes to your vitamin intake.
Sources and full results
Most relevant research papers on this topic
Hiding in Plain Sight: Modern Thiamine Deficiency
Modern thiamine deficiency rates range from 20% to over 90%, suggesting the RDA may be insufficient to meet modern living demands.
Vitamin B1, eye and brain
Vitamin B1 deficiency can cause nerve, visual, and heart problems, and should be addressed with a daily 0.4 mg dose per 1000 kcal.
Thiamin (Vitamin B1) – A scoping review for Nordic Nutrition Recommendations 2023
Thiamine deficiency can be observed at intakes below 0.5 mg/day, with a lower limit of intake at 0.05 mg/MJ, and a higher requirement for pregnant and lactating women and elderly individuals.
Literature ReviewMetabolic Effects of Vitamin B1 Therapy under Overnutrition and Undernutrition Conditions in Sheep
High-dose thiamine therapy reduces liver fat in sheep under overnutrition conditions, but has no effect on body weight or blood glucose, but may increase fatty acid utilization as a source of energy.
RCT
Animal Study
Very Rigorous JournalWernicke's encephalopathy in acute and chronic kidney disease: a systematic review.
High doses of parenteral thiamine can prevent Wernicke's encephalopathy in patients with kidney disease and severe malnutrition.
Systematic ReviewEffects of thiamine supplementation on exercise-induced fatigue
High-dose thiamine supplementation (100 mg/day) can help prevent and accelerate recovery from exercise-induced fatigue in male athletes.
RCTThiamine dose response in human milk with supplementation among lactating women in Cambodia: study protocol for a double-blind, four-parallel arm randomised controlled trial
The dose of thiamine supplementation in lactating women in Cambodia needs to be determined to optimize infant thiamine levels and combat thiamine deficiency.
RCT
Rigorous Journal