Which Individual Has the Greatest Need for Thiamin? Understanding High-Risk Groups

January 11, 2026 •

3 min read

Up to 80% of individuals with chronic alcoholism may develop a thiamin deficiency due to poor intake and impaired absorption. This highlights a crucial health concern: Which individual has the greatest need for thiamin, and what puts them at such high risk? While most people get enough from their diet, specific populations face significantly elevated risks that demand attention.

Quick Summary

Identify the populations most vulnerable to thiamin deficiency, including those with alcohol use disorder, malabsorption issues, bariatric surgery patients, and older adults, to understand their heightened nutritional requirements.

Key Points

Chronic Alcohol Use: Individuals with alcohol use disorder are at the highest risk for severe thiamin deficiency due to poor nutrition and impaired absorption.
Post-Bariatric Surgery Patients: These patients require significant and often lifelong thiamin supplementation because of intestinal changes leading to malabsorption.
Infants of Deficient Mothers: Exclusively breastfed infants born to thiamin-deficient mothers face the highest risk of acute, rapidly fatal infantile beriberi.
Pregnancy and Lactation: This period increases the body’s thiamin requirements to support both the mother and the developing infant.
Older Adults: The elderly are highly susceptible to deficiency due to age-related changes in diet, metabolism, and medication use.
Chronic Illnesses: Conditions like diabetes, heart failure, and HIV/AIDS increase the body’s need for thiamin or impair its utilization.
Severe Consequences: Without timely treatment, severe thiamin deficiency can cause permanent neurological damage and death from conditions like Wernicke-Korsakoff syndrome and beriberi.

The Importance of Thiamin (Vitamin B1)

Thiamin, also known as vitamin B1, is essential for converting food into energy and plays a critical role in the function of the nervous system, brain, and heart. The body stores limited amounts, primarily in the liver, making regular dietary intake necessary to maintain adequate levels. Insufficient thiamin can lead to various health issues, from mild fatigue to severe conditions like beriberi and Wernicke-Korsakoff syndrome.

High-Risk Groups with Heightened Thiamin Needs

While thiamin deficiency is uncommon in the general population in many countries, certain conditions and lifestyle factors significantly increase an individual's risk. The greatest need often arises from a combination of poor intake and impaired absorption or metabolism.

Individuals with Alcohol Use Disorder

Chronic alcohol misuse is a leading cause of severe thiamin deficiency in developed nations, affecting a large percentage of heavy drinkers. Alcohol negatively impacts thiamin status through several mechanisms, including poor dietary intake, reduced absorption in the damaged gastrointestinal tract, increased excretion, and impaired utilization due to liver damage. This deficiency can manifest as Wernicke-Korsakoff syndrome, a serious neurological condition.

Patients Post-Bariatric Surgery

Individuals who have undergone weight-loss surgery, particularly procedures like gastric bypass, are at high risk of thiamin deficiency. The surgical changes restrict food intake and bypass sections of the intestine responsible for nutrient absorption, severely affecting thiamin uptake. Lifelong supplementation is typically required to prevent severe neurological complications.

Individuals with Malabsorption Syndromes

Chronic digestive disorders like Crohn's and celiac disease, which cause malabsorption, increase the risk of thiamin deficiency. Intestinal damage and chronic diarrhea hinder the normal absorption of thiamin.

Pregnant and Lactating Women

Increased thiamin is needed during pregnancy and breastfeeding to support both the mother and the developing baby. A deficiency during this time can result in infantile beriberi, impacting the infant's neurological and cardiac health.

Older Adults

Older adults are more susceptible to suboptimal thiamin levels. Contributing factors include reduced food intake, chronic illnesses, medications (such as diuretics), and age-related changes in absorption.

Individuals with Chronic Diseases

Chronic conditions such as diabetes, HIV/AIDS, heart failure, and those undergoing renal dialysis can also increase the risk of thiamin deficiency due to factors like increased excretion, impaired metabolism, or malnutrition.

Addressing the Need for Thiamin

Preventing thiamin deficiency involves ensuring adequate dietary intake, potentially through supplementation in high-risk individuals. Severe deficiency often requires high-dose thiamin administration. Early intervention is crucial to minimize the risk of long-term health issues.


High-Risk Group	Primary Reason for High Need	Symptoms of Deficiency	Treatment Approach
Chronic Alcohol Use	Poor intake, impaired absorption, increased excretion	Confusion, ataxia, memory loss (Wernicke-Korsakoff), fatigue	High-dose parenteral thiamin, oral supplementation, and abstinence
Bariatric Surgery Patients	Significant malabsorption due to altered anatomy	Similar to alcoholism, can lead to severe neurological issues	Lifelong micronutrient supplementation, including thiamin
Pregnant & Lactating Women	Increased demand for fetal/infant development	Infantile beriberi in baby, fatigue, nausea in mother	Increased dietary intake and prenatal supplementation
Older Adults	Low intake, comorbidities, polypharmacy, reduced absorption	Memory problems, confusion, neuropathy	Dietary improvements and potentially oral supplementation
Malabsorption Syndromes	Chronic gut issues hindering absorption	Peripheral neuropathy, fatigue, gastrointestinal issues	Supplementation and addressing the underlying condition

Conclusion

Individuals with chronic alcohol use disorder face the most significant and severe need for thiamin in industrialized countries, often leading to serious conditions like Wernicke-Korsakoff syndrome. However, other groups including bariatric surgery patients, pregnant and lactating women, older adults, and those with chronic diseases or malabsorption also have increased requirements and may need targeted supplementation. Identifying these at-risk populations and intervening appropriately is vital to prevent the potentially irreversible consequences of thiamin deficiency. For more information, the NIH Office of Dietary Supplements provides a fact sheet on thiamin.

Frequently Asked Questions

Individuals with chronic alcohol use disorder have the highest likelihood of developing severe thiamin deficiency and its complications, such as Wernicke-Korsakoff syndrome, due to a combination of poor diet and impaired absorption.

Bariatric surgery alters the digestive tract, which can lead to significant malabsorption of nutrients. The changes reduce both the amount of food consumed and the area for nutrient absorption, resulting in a severe thiamin deficiency.

Infants exclusively breastfed by a thiamin-deficient mother can develop infantile beriberi, a severe and often rapidly fatal condition affecting the nervous system and heart. It can cause heart failure and neurological issues.

Many older adults are at risk of inadequate thiamin intake due to a reduced appetite, chronic health conditions, and drug interactions from multiple medications. Dietary intake is often insufficient, making supplementation potentially necessary.

Early symptoms of thiamin deficiency are often vague and can include fatigue, irritability, poor memory, abdominal discomfort, and a loss of appetite.

Mild deficiencies can often be corrected with oral thiamin supplements and a healthy diet. For severe deficiencies, especially Wernicke-Korsakoff syndrome, high-dose thiamin is typically administered intravenously.

Excellent food sources of thiamin include whole and enriched grains, fortified cereals, legumes, nuts, seeds, pork, and certain fish like trout and tuna.

Studies have shown that individuals with diabetes often have lower blood thiamin levels compared to healthy individuals. This might be due to increased clearance of thiamin by the kidneys.