The B vitamin complex includes eight vitamins. Vitamin B1, or thiamin, is an important one among them. Thiamin is a water-soluble vitamin and has important roles in metabolism.
In addition to fortified cereals, pork is a major food source of vitamin B1.
What is the function of vitamin B1 in our body?
Vitamin B1 has an important role in energy metabolism and helps activate enzymes involved in energy metabolism. Therefore, it’s necessary for cells to function properly and for promoting optimal growth and development.
It plays a critical role in generating ATP, the basic energy molecule in the body. It’s also involved in the metabolism of certain amino acids like leucine, isoleucine and valine, as well indirectly in fat metabolism. The metabolically active version of B1 is known as thiamine diphosphate.
What are good sources of vitamin B1?
Whole grains, meat and fish are good sources of vitamin B1. Parboiling rice has been shown to enrich vitamins including B1 vitamin. Rice bran and bran oil are also very good sources.
In the United States, bread, cereals and milk are fortified with thiamin. Bread and cereals form an important source of vitamin B 1 in a child’s diet. Pork is also a major source.
Cooking can reduce thiamin levels by 30%. Since the vitamin is water soluble, cooking with water and throwing away the cooking water can also reduce the vitamin content. Natural sources form 50% of the dietary source of vitamin B1 in your child’s diet, and the rest comes from fortification of foods in the U.S.
Thiamin is absorbed in the small intestine. The vitamin is mostly stored in the liver and the storage is limited. Therefore, your child’s body needs a regular source of vitamin B1. The gut bacterial flora makes vitamin B1, but in very small quantities – too small to be significant.
What causes thiamin deficiency?
Fortunately, thiamin deficiency is uncommon in United States and other developed countries. Thiamin deficiency can occur due to poor dietary intake, poor gastrointestinal absorption and, sometimes, due to rapid weight loss.
Children who may have poor nutritional status (malnutrition) or with tendencies for limited dietary intake and not on vitamin supplementation – for example, children with autism or with eating disorders – may be prone for thiamin deficiency.
Poor absorption may be seen in children with short bowel syndrome (from many causes) and sometimes in children with disorders affecting the mucosa (lining of the bowel), who also have severe malnutrition. For adults, chronic alcoholism is a well-known cause of thiamin deficiency, as it decreases B1 absorption and storage.
Patients with poorly controlled Type 1 or 2 diabetes may be prone to developing thiamin deficiency, due to high urine loss. The relevance of low thiamin status and benefit of extra supplementation in these patients are not clear at this point.
Patients with HIV/AIDS may develop low thiamin status, secondary to poor nutritional state.
Long-term use of Furosemide, a medicine use to treat fluid overload by increasing urine output, may cause B1 deficiency. This is likely due to higher urinary losses and the significance of this needs further investigation to look at the practicality of supplementation.
What are the symptoms of thiamin deficiency?
In early stages of thiamin deficiency, patients may have worsening weight loss and reduced appetite, confusion and short-term memory loss, muscle weakness and heart-related symptoms such as heart failure.
The classic presentation of thiamin deficiency is called beriberi, where patients develop symptoms of involvement of the nerves of the body, particularly the arms and legs, causing weakness, loss of sensation and wasting of muscles (peripheral neuropathy). Rarely, it can cause heart failure, causing excess fluid accumulation in the body, sometimes with poor outcomes.
Beriberi is uncommon in United States, but may be seen. Wernicke-Korsakoff’s syndrome, though rare, is relatively more common compared to beriberi. Though this is seen in older patients with chronic alcoholism, it may been seen in older children with poor nutritional status from long-term gastrointestinal disease or other causes of severe malnutrition, who are being given intravenous sugar (dextrose). A fifth of these patients could have a fatal outcome if not treated.
How is thiamin deficiency diagnosed?
Doctors may suspect thiamin deficiency based on the clinical profile and looking for potential underlying causes. Physicians may measure thiamine levels in blood, but the levels could vary based on short-term intake of thiamine, making interpretation difficult.
The best tests may be available through certain specialized centers by measuring an enzyme activity that is dependent on thiamin for its activity. Urine thiamin levels may also be a useful tool.
How is thiamin deficiency treated?
Identifying high-risk patients and supplementing vitamins, including B1 vitamin, is best way to prevent thiamine deficiency. Age appropriate dosing and formulation should be discussed with your child’s pediatrician or primary care provider.
Ensuring that your child eats a good thiamin-containing diet always keeps you a step ahead. Once symptoms related to thiamin deficiency are suspected, doctors may order tests to confirm the diagnosis.
However, we do not wait for the tests to treat due to the potential serious nature of the deficiency. These patients are sick and have to be monitored and treated in hospitals, sometimes in an intensive care setting. Doctors decide on the dose of thiamin based on the child’s weight and age. In severe deficiency states, the initial doses are given intravenously, followed by oral supplementation.