Vitamin B1

Vitamin B1, also called thiamin, was the first B vitamin ever discovered. Your body uses it to process fats, carbohydrates, and proteins. Every cell in your body needs thiamin to make adenosine triphosphate, or ATP, the body's main energy-carrying molecule. The heart, in particular, has considerable need for thiamin in order to keep up its constant work. Severe deficiency results in beriberi, a disease common among sailors through the nineteenth century, but rare today. Beriberi is still seen, however, in developing countries as well as in alcoholics and people with diseases that significantly impair the bodys ability to absorb vitamin B1. Many of the principal symptoms of beriberi relate to impaired heart function.

Your need for vitamin B1 varies with age. The official U.S. and Canadian recommendations for daily intake are as follows:

• Infants 0–6 months, 0.2 mg 7–12 months, 0.3 mg
   
• Children 1–3 years, 0.5 mg 4–8 years, 0.6 mg 9–13 years, 0.9 mg
   
• Males 14 years and older, 1.2 mg
   
• Females 14–18 years, 1.0 mg 19 years and older, 1.1 mg
   
• Pregnant or nursing women, 1.4 mg

Alcoholism, congestive heart failure, Crohns disease, anorexia, kidney dialysis, folate deficiency, and multiple sclerosis may all lead to a vitamin B1 deficiency, and people with these conditions should consider taking B1 supplements. Certain foods may impair your bodys absorption of B1 as well, including fish, shrimp, clams, mussels, and the herb horsetail.
Brewers and nutritional yeast are the richest sources of B1. Peas, beans, nuts, seeds, and whole grains also provide fairly good amounts.

Very high dosages of B1—up to 8 g daily—have been recommended for a variety of conditions. Since the B vitamins tend to work together, many nutritional experts recommend taking B1 with other B vitamins in the form of a B-complex supplement.

Congestive heart failure (CHF) is a condition in which the pumping ability of the heart declines, and fluid begins to accumulate in the lungs and legs. Standard treatment for CHF includes strong water pills called loop diuretics. These diuretics, however, deplete the body of B1. Since the heart depends on vitamin B1 for its proper function, this is potentially quite worrisome. There is some evidence that supplementation with B1 can improve symptoms. Individuals with alcoholism, Crohns disease, anorexia, or multiple sclerosis may also benefit from thiamin supplementation as part of general nutritional support. An observational study found that HIV-positive men with the highest intakes of thiamin and other B vitamins had significantly longer survival rates, while a similar study found that those taking the most B1 or niacin had a significantly lower rate of developing AIDS. In addition, weak and contradictory evidence suggests that vitamin B1 may be helpful for Alzheimers disease.Vitamin B1 has also been proposed as a treatment for epilepsy, canker sores, and fibromyalgia, but the evidence for these uses is too preliminary to cite.

Congestive Heart Failure Evidence suggests that individuals with congestive heart failure are commonly deficient in vitamin B1, due to their use of loop diuretics. Preliminary evidence, including a small double-blind trial, suggests that thiamin supplements might help.

Vitamin B1 appears to be quite safe even when taken in very high doses.

If you are taking loop diuretics—for example, furosemide (Lasix)—you may need extra vitamin B1.