Which of the following populations are at highest risk potential thiamin B1 deficiency?

October 21, 2025 •

3 min read

According to the National Institutes of Health, chronic alcohol use is one of the most common causes of thiamin deficiency in developed countries. This highlights that while thiamin deficiency can result from inadequate diet, medical and lifestyle factors significantly increase risk, answering the question of which of the following populations are at highest risk potential thiamin B1 deficiency. Several other groups are also highly vulnerable, often due to poor nutritional intake, reduced absorption, or increased metabolic demand.

Quick Summary

Chronic alcohol users are at the highest risk for thiamin deficiency, along with individuals who have undergone bariatric surgery, are malnourished, have certain chronic illnesses, or use specific medications like diuretics. Infants breastfed by deficient mothers and people with Wernicke-Korsakoff syndrome are also highly vulnerable.

Key Points

Chronic alcohol use: The most common cause of thiamin deficiency in industrialized countries, stemming from poor diet, reduced absorption, and impaired utilization.
Post-bariatric surgery patients: At high risk due to changes in the digestive system that lead to malabsorption and restricted food intake.
Malnourished individuals: Includes those with eating disorders (e.g., anorexia nervosa), starvation, or poor diets centered on refined carbohydrates.
Infants breastfed by deficient mothers: Exclusively breastfed infants of thiamin-deficient mothers are a specific and particularly vulnerable population.
Older adults: Increased risk due to lower dietary intake, chronic diseases, and potential use of medications like diuretics.
Individuals with chronic diseases: Patients with conditions such as HIV/AIDS, diabetes, or liver disease are at a higher risk.
Chronic diuretic use: Medications like furosemide can increase the urinary excretion of thiamin, leading to a deficiency over time.

Thiamin (vitamin B1) is a vital, water-soluble vitamin essential for converting food into energy and plays a crucial role in nerve, heart, and brain function. The body cannot produce it and stores it for only a short period. While a balanced diet generally prevents deficiency, certain conditions and lifestyles significantly increase risk, making early identification of high-risk groups important.

Populations at the Highest Risk for Thiamin Deficiency

Chronic Alcohol Users

Chronic alcohol use disorder is the leading cause of thiamin deficiency in industrialized nations. Alcohol reduces thiamin levels through poor dietary intake, impaired absorption, reduced liver storage, and by blocking its conversion to the active form. Severe deficiency can lead to Wernicke-Korsakoff syndrome.

Post-Bariatric Surgery Patients

Bariatric surgery patients face high risk due to altered digestion leading to malabsorption and restricted food intake. This risk, particularly after gastric bypass, can result in severe deficiency and conditions like Wernicke's encephalopathy.

Individuals with Malnutrition or Eating Disorders

Severely restricted food intake, as seen in eating disorders like anorexia nervosa or bulimia, increases deficiency risk. In malnourished individuals, re-feeding can rapidly deplete thiamin stores. Diets heavily reliant on refined carbohydrates also pose a risk globally.

Older Adults

Older adults are more susceptible due to lower dietary intake, multiple medications that affect thiamin (like diuretics), and chronic diseases that increase demand.

Chronic Illnesses and Medical Conditions

Chronic conditions can impact thiamin absorption or utilization. People with diabetes, HIV/AIDS, or those undergoing dialysis are at higher risk. Long-term diuretic use also increases thiamin excretion.

Comparison of Risk Factors for Thiamin Deficiency


Risk Factor Category	Primary Mechanism of Deficiency	Symptoms Most Affected	Treatment Approach
Chronic Alcohol Use	Decreased intake, impaired absorption and utilization.	Neurological (Wernicke-Korsakoff syndrome), nerve damage.	High-dose parenteral (IV/IM) thiamin supplementation, cessation of alcohol use.
Bariatric Surgery	Decreased nutrient absorption, reduced food intake.	Neurological (Wernicke-Korsakoff syndrome).	Lifelong micronutrient supplementation, including thiamin.
Eating Disorders	Severely restricted dietary thiamin intake.	Fatigue, memory issues, irritability, nerve damage.	Repletion via supplementation, nutritional rehabilitation.
Older Adults	Lower intake, polypharmacy, chronic disease.	Vague symptoms, can worsen cognitive function or nerve issues.	Dietary and supplemental thiamin, monitoring.
Infantile Beriberi	Exclusive breastfeeding by thiamin-deficient mother.	Rapidly progressing heart failure, voice loss, neurologic signs.	Immediate direct thiamin supplementation to infant.
Chronic Diuretic Use	Increased thiamin excretion in urine.	Symptoms may exacerbate heart failure, affecting energy.	Careful monitoring, potential thiamin supplementation.

Conclusion

While thiamin deficiency is rare in the general healthy population of industrialized countries, several groups are at significantly higher risk. Chronic alcohol users are particularly vulnerable due to a combination of factors. Other high-risk groups include those who have undergone bariatric surgery, individuals with eating disorders or general malnutrition, older adults with multiple health issues, and people with chronic diseases like diabetes or HIV/AIDS. Infants breastfed by a deficient mother are also highly susceptible. Recognizing these risk factors is vital for preventing serious consequences like Wernicke-Korsakoff syndrome and beriberi. Early intervention with thiamin supplementation is key to managing deficiency. For more information, consult reliable sources like the National Institutes of Health.

Frequently Asked Questions

In industrialized countries, the most common cause of thiamin deficiency is chronic alcohol use disorder, which leads to poor nutritional intake, reduced absorption, and impaired thiamin utilization.

Patients who have undergone bariatric surgery are at risk because the procedure alters the digestive tract, leading to malabsorption of nutrients. Additionally, their restricted food intake contributes to lower overall thiamin consumption.

Yes, a diet consisting mainly of highly processed carbohydrates, such as polished white rice or white flour, which lack thiamin, can cause a deficiency. This is especially true in regions with high food insecurity.

Infants exclusively breastfed by a thiamin-deficient mother can develop infantile beriberi, which may present with acute heart failure, voice loss, and neurological signs. This condition can be life-threatening if not treated promptly.

Wernicke-Korsakoff syndrome is a severe neurological disorder caused by advanced thiamin deficiency, most commonly associated with chronic alcohol use. It has two stages: Wernicke encephalopathy (causing confusion and eye movement problems) and Korsakoff psychosis (leading to memory loss and confabulation).

Yes, older adults are at a higher risk due to lower dietary intake, the presence of multiple chronic diseases, and the use of certain medications that can affect thiamin levels, such as diuretics.

Chronic diseases that increase risk include HIV/AIDS, diabetes, liver disorders, and conditions causing chronic vomiting or diarrhea. Patients on dialysis or long-term diuretic therapy are also at higher risk.