Sources of Vitamin B1
The richest dietary sources of thiamin are unrefined cereals and grains, lean pork, beans, nuts, and seeds. In the United States, refined flours, stripped of their thiamin, are a nutritional reality, so most Americans get most of their thiamin from breads and cereals enriched with additional B1.
The vitamin easily dissolves in water, is vulnerable to heat during cooking, and to baking soda and powder in baked goods. It is a component of the germ and bran of wheat, the husk of rice, and that portion of all grains that is commercially milled out to give the grain a lighter color and finer texture.
Deficiency of Vitamin B1
Thiamin deficiency causes Beri-beri, which is frequently seen in parts of world where polished rice is predominantly eaten. Childhood beri-beri stunts growth in infants and children. Wet beriberi is classic form with swelling due to fluid retention (edema) in lower limbs which spreads to upper body, affecting heart and leading to heart failure. Dry beriberi affects peripheral nerves, initially causing tingling and burning sensation in lower limbs and progressing to nerve degeneration, muscle wasting and weight loss.
Heavy alcohol consumptions lead to Thiamine deficiency disease – Wernicke-Korakoff syndrome. It is caused by poor food intake and decreased absorption and in increased excretion caused by alcohol consumption.