Vitamin B-1 (Thiamine) (also spelled “thiamin”)
Function of Thiamine: works to help break down carbohydrates and plays a role in nerve conduction.
Deficiency States: Also associated with malabsorption, dialysis, and protein-calorie under nutrition. In addition to insufficient intakes of thiamin from the diet, the causes of thiamin deficiency include lower absorption or higher excretion rates than normal due, for example, to certain conditions (such as alcohol dependence or HIV/AIDS) or use of some medications.
- Dry beriberi: affects the nervous system and may cause psychiatric disturbances.
- Wet beriberi: may cause heart problems and leads to overall weakness.
Alcoholics: Most thiamine deficiencies in the US are due to alcoholism. Chronic alcohol use disorders appear to be the most common cause of thiamin deficiency. Up to 80% of people with chronic alcoholism develop thiamin deficiency because alcohol intake reduces gastrointestinal absorption of thiamin, thiamin stores in the liver, and thiamin metabolism.
People with alcoholism tend to have poor nutritional intake and therefore inadequate intakes of essential nutrients, including thiamin. Wernicke-Korsakoff syndrome is one of the most severe psychiatric symptoms of alcohol abuse. All patients with alcohol abuse should be supplemented with thiamine.
Other patient groups prone to thiamine deficiency:
- Patients with HIV/AIDS
- People with Type-1 and Type-2 diabetes have 75% less thiamine levels (increase kidney excretion)
- People with gastric bypass surgery
- Furosemide (Lasix) increases the clearance of thiamine from the kidneys leading to deficiency.
- Other intake deficiencies: dieting, starvation nausea of pregnancy
Dosing of Thiamine (Vitamin B-1):
- Dietary requirements for thiamine are only 1 to 2 mg daily, absorption and utilization of thiamine are incomplete, and some patients have genetically determined requirements for much larger dose. Most over the counter once daily vitamins contain 1.5 mg of thiamine.
- Most patients are started on IV thiamine in the hospital, after discharge daily oral administration of 100 mg of thiamine Vitamin B-1, is recommended until the patient is no longer at risk.