The chief symptoms of a disease called “beriberi” are due to a lack of one of the portions of the vitamin B complex called thiamin. Thiamin is soluble in water, damaged by heat and found chiefly in whole cereals, peas, beans, lean meats, nuts and yeast. Refined sugar, milled rice and low-extraction flour have lost most of their thiamin.
People whose diets are low in protein and high in carbohydrates are likely to show symptoms of thiamin deficiency. In the United States the condition is seen often among chronic alcoholics who get insufficient amounts of the right foods because of their displacement by alcohol.
The chief damages to tissues of the body seen in thiamin deficiency are found in the nerves and in the heart and blood vessels. Often these tissues become swollen with water. After about three months on a diet really deficient in thiamin the symptoms begin to appear. Gradually the person becomes tired and irritable and the muscles, particularly those of the calf of the leg, become painful. Later serious inflammations of the nerves appear, and these may go on to the point of loss of sensation and paralysis. When neuritis becomes so prominent, the doctor must make sure that it does not result from some other cause, since lead or arsenic poisoning or various infections may also cause neuritis.
As soon as a sufficient intake of thiamin is assured the patient begins to improve. Thiamin is now available in the form of tablets or capsules that can be taken internally, and also in forms that can be injected into the body when prompt action is desired. If treatment is begun sufficiently early most patients recover rapidly and completely. If treatment is delayed until actual destruction of nerve tissue has occurred, results are doubtful.