Thiamine is a water-soluble B-complex vitamin, previously known as B1, that was one of the first organic compounds to be recognized as a vitamin. Dietary sources of thiamine include beef, pork, brewer’s yeast, legumes such as beans and lentils, milk, nuts, oats, oranges and whole-grain cereals. White flour and white rice are often fortified with thiamine to replace the vitamin lost during refining.

Benefits: Thiamine is needed for nervous system and muscle functioning, the flow of electrolytes in and out of nerve and muscle cells, various enzyme processes, and digestion. Very little thiamine is stored in the body, so depletion can occur within 14 days. Severe thiamine deficiency is known as beriberi, a condition characterized by loss of muscle control and mental confusion. It is extremely rare in the U.S. due to fortification of foods. Use of oral contraceptives, antibiotics, antacids and sulfa drugs may decrease thiamine levels in the body. No upper limit for thiamine intake has been established.

Daily recommended amount:

Men: 1,200 micrograms

Women: 1,100 micrograms

Pregnant women: 1,400 micrograms

Lactating women: 1,400 micrograms

Children (0-6 months): 200 micrograms

Children (7-12 months): 300 micrograms

Children (1-3): 500 micrograms

Children (4-8): 600 micrograms

Children (9-13): 900 micrograms

Children (14-18): 1,000 micrograms

Good sources:

PowerBar: 5,500 micrograms

MultiGrain Cheerios: 1,600 micrograms

Pork chop (5.5 oz.): 800 micrograms

Sirloin steak (14 oz.): 300 micrograms

Black beans (1 cup): 400 micrograms

Milk (2%, 1 cup): 100 micrograms

— Markian Hawryluk, The Bulletin

Sources: National Institutes of Health, NutritionData.com