Vitamin B1 (thiamine) is a water-soluble vitamin necessary for the conversion of fats, carbohydrates and amino acids into energy. It has also been called the 'morale' vitamin because it ensures proper nerve impulse transmission and has a beneficial effect on mental attitude.
Vitamin B1 is needed for the body's manufacture of hydrochloric acid for digestion. Deficiencies result in two forms of beriberi: wet beriberi which accumulates water in cells and joints; and dry beriberi causes muscle wasting and emaciation. Both types cause digestive problems, fatigue, and weight loss. Prolonged deficiencies of vitamin B1 can result in permanent damage to the nervous system and memory.
Vitamin B1 may be in short supply in your diet due to foods that lack it due to processing as cooking also removes it, diets high in fats and sugar, the overuse of alcohol or dieting and fasting.
Vitamin B1 is reputed to be a mosquito and insect repellent when 100 mg or more is taken daily. Vitamin B1 may improve digestive muscle tone, and even improve dental post-operative and dry socket pain and healing. Vitamin C has been included because it has a positive synergistic effect with all the other B vitamins.
There is no known toxicity with oral consumption of vitamin B1. It's preferable to take a B-complex in addition to a single B vitamin. Never take high doses of a single B vitamin without increasing the amount you take of all the others. This is not only because the B vitamins tend to work together, it is also because B vitamins compete in the intestines for absorption by the body; for example, if you take an enormous amount of B1, you might decrease the amount of B3 absorbed and end up with a B vitamin imbalance.