Thiamin is a water-soluble nutrient that was the first of the eight B-vitamins to be discovered, hence its name vitamin B1.
Severe thiamin deficiency causes a syndrome known as “beriberi”. In the early 20th century, doctors discovered that when sailors ate a diet of white rice they were likely to suffer from muscular weakness, energy deprivation, and inactivity. The addition of whole grains to ships rations helped to prevent the occurrence of this syndrome.
Vitamin B1 is essential for energy production and carbohydrate metabolism. The body needs thiamin to manufacture adenosine triphosphate or ATP, a molecule which every cell of the body uses for energy.
Thiamin also plays a key role in support of the nervous system, where it permits healthy development of the fat-like coverings which surround most nerves (called myelin sheaths). In the absence of B1, these coverings can degenerate or become damaged. Pain, prickly sensations, and nerve deadening are nerve-related symptoms that can result from vitamin B1 deficiency.
Like other B-complex vitamins, thiamin is sometimes called an “anti-stress” vitamin because it may strengthen the immune system and improve the body’s ability to withstand stressful conditions.
No B-vitamin is more dependent on its fellow B-vitamins than thiamin. Absorption of thiamin into the body requires adequate supplies of vitamins B6, B12, and folic acid.
Essential for energy production and carbohydrate metabolism
Helps metabolize fats and protein
Supports the development of a healthy nervous system
Coordinates the activity of nerves and muscles
Enhances the body’s ability to react to stress
The best source of thiamin is from whole grains including rice, legumes, wheat germ, bran and brewer’s yeast. Today, most packaged/processed foods that don’t use whole grains (e.g., cereals, breads, pasta) are fortified with vitamin B1. Thiamin is also found in lean meats and fish.
Fruits and vegetables are not very high in thiamin but when eaten in sufficient quantity can be a good source of this vitamin. Good options include asparagus, Brussels sprouts, cauliflower, crimini mushrooms, kale, oranges, peas, potatoes, soybeans, and spinach.
Vitamin B1 is highly unstable and easily damaged by heat. Long-term (e.g. 12 months) refrigeration of B1-containing foods can also result in substantial loss of this nutrient.
Recommended Dietary Allowance
The Recommended Dietary Allowance (RDA) for thiamin is 1.2 mg for adult men and 1.1 mg for adult women. No upper level of intake has been established by the Institute of Medicine.
If you look on a nutritional supplement facts panel, you’ll notice the Amount Per Serving for vitamin B1 and the % Daily Values is at located at the top of the panel. The Amount Per Serving is based on the Reference Daily Intake (RDI) for this nutrient which is considered to be sufficient to meet the requirements of nearly all (97–98%) healthy individuals in each life-stage and sex group. The Reference Daily Intake for Vitamin B1 is 1.5 mg which represents 100% of the Daily Values.
Alcoholism is the leading risk factor for vitamin B1 deficiency in the U.S. Heavy users of coffee and tea may also have increased risk of vitamin B1 deficiency, since these beverages act as diuretics and remove both water and water-soluble vitamins (like B1) from the body. Our need for vitamin B1 is also increased by chronic stress and smoking.
Clinical Support Program and Recovery Support Program are both formulated with 52.5 mg of vitamin B1. Vitamin B1 is included in Energy Support (45 mg) and Bone Support (7.5 mg). Our Multi-Vitamin & Mineral, which combines both products, is formulated with 52.5 mg of vitamin B1. Anti-Aging Formula is formulated with 35 mg.
Last updated July 1, 2018
David H. Rahm, M.D. is the founder and medical director of The Wellness Center, a medical clinic located in Long Beach, CA. Dr. Rahm is also president and medical director of VitaMedica. Dr. Rahm is one of a select group of conventional medical doctors who have education and expertise in functional medicine and nutritional science. Over the past 20 years, Dr. Rahm has published articles in the plastic surgery literature and educated physicians about the importance of good peri-operative nutrition.