What group of people are at risk for vitamin deficiency?

October 17, 2025 •

4 min read

Globally, almost 2 billion people are at risk of micronutrient deficiencies, a condition commonly known as 'hidden hunger'. Understanding what group of people are at risk for vitamin deficiency is crucial for prevention and early intervention, from pregnant women to older adults and those with specific health issues.

Quick Summary

Several populations, including older adults, pregnant women, and individuals with chronic diseases, face a higher likelihood of vitamin deficiency. Poor dietary choices, limited nutrient absorption, and increased physiological needs contribute to inadequate vitamin levels. Identifying these risk factors is vital for managing nutritional health.

Key Points

Older Adults: Experience reduced appetite, less efficient absorption of B12 due to lower stomach acid, and decreased vitamin D synthesis from sunlight, increasing deficiency risks.
Pregnant Women: Have significantly higher nutritional needs for vitamins like folate, iron, and B12, making them vulnerable to deficiencies that can impact both maternal and fetal health.
Vegans and Vegetarians: Are at higher risk for low intake or poor absorption of vitamin B12, vitamin D, calcium, and iron due to the exclusion of animal products from their diet.
Chronic Alcoholics: Suffer from poor dietary intake and impaired vitamin absorption, metabolism, and storage, leading to frequent deficiencies, especially in B vitamins.
Digestive Disorder Patients: Conditions like Crohn's and celiac disease can cause malabsorption, leading to deficiencies in fat-soluble vitamins (A, D, E, K) and B vitamins.
Limited Sun Exposure: Individuals who stay indoors, use heavy clothing, or live in certain climates are at high risk of vitamin D deficiency, as sunlight is the primary source.
Lower Income Populations: Often face food insecurity and lack access to diverse, nutrient-rich foods, increasing their susceptibility to various micronutrient deficiencies.

Who is at heightened risk for vitamin deficiencies?

While anyone can experience a vitamin deficiency, certain demographic, lifestyle, and health-related factors place some individuals at a significantly higher risk. These at-risk groups often have increased physiological needs, limited dietary intake, or impaired nutrient absorption, making them susceptible to a range of health issues stemming from inadequate vitamin levels.

Older adults

As people age, several physiological and lifestyle changes can increase the risk of nutrient deficiencies. Older adults often experience a decreased appetite, reducing their overall calorie and vitamin intake. Digestive changes, such as reduced stomach acid production, can interfere with the absorption of key nutrients like vitamin B12. Additionally, medication use, which is common in this population, can impact the body's ability to absorb or utilize certain vitamins. A meta-analysis found a high prevalence of vitamin D deficiency among older adults in South Asia, for instance.

Common deficiencies in older adults:

Vitamin D: Skin's ability to synthesize vitamin D from sunlight declines with age, and many older individuals spend less time outdoors.
Vitamin B12: Often linked to reduced stomach acid needed for absorption.
Calcium: Critical for bone health, working alongside vitamin D.
Magnesium: Involved in blood pressure and glucose regulation.

Pregnant and lactating women

Pregnancy and breastfeeding dramatically increase the demand for specific vitamins and minerals to support both maternal health and fetal development. Inadequate nutrition during this period can have serious consequences for both mother and child. For example, deficiencies can lead to low birth weight, developmental impairments, and an increased risk of complications. Folic acid fortification has significantly reduced folate deficiency in some regions, but deficiencies in other areas persist.

Individuals with digestive disorders

Conditions that affect the gastrointestinal (GI) tract can severely compromise the body’s ability to absorb nutrients. Inflammatory bowel diseases (IBD) like Crohn's disease, celiac disease, and even stomach surgeries such as gastric bypass can impair absorption. These individuals may experience deficiencies in both water-soluble and fat-soluble vitamins, even with a seemingly adequate diet.

Digestive issues and absorption problems:

Fat-soluble vitamins (A, D, E, K): Malabsorption of fats, common in several GI disorders, limits the absorption of these vitamins.
B vitamins: Inflammation and damage to the intestinal lining can impede the absorption of B-complex vitamins, including B12 and folate.

People on restrictive diets

Dietary choices can be a major risk factor for vitamin deficiency. Vegans and vegetarians, particularly those who do not supplement their diet properly, are susceptible to deficiencies in nutrients predominantly found in animal products. Low-income populations with limited access to diverse, nutrient-rich foods are also at risk.

Vulnerabilities in restrictive diets:

Vegans/Vegetarians: Face higher risks for vitamin B12, vitamin D, iodine, calcium, and zinc.
Low-income populations: Often rely on nutrient-poor staple foods, leading to widespread deficiencies.

People with limited sun exposure

Vitamin D is uniquely produced by the body in response to sunlight. Individuals who spend a lot of time indoors, wear extensive clothing for cultural or other reasons, or live in regions with little sunlight, are at an increased risk of vitamin D deficiency.

Chronic alcoholism

Excessive and chronic alcohol consumption is a significant cause of malnutrition, including severe vitamin deficiencies. Alcohol interferes with the absorption, storage, and metabolism of many vitamins, particularly B-complex vitamins and folate. Chronic alcoholics frequently suffer from multiple vitamin deficiencies, leading to various neurological disorders.

Comparison of at-risk groups and contributing factors


At-Risk Group	Common Deficiencies	Primary Contributing Factors
Older Adults	B12, D, Calcium	Decreased appetite, reduced stomach acid, less sun exposure, medication use
Pregnant Women	Folate, Iron, B12, Vitamin D	Increased physiological demands to support fetal development
Vegans/Vegetarians	B12, D, Calcium, Iron	Absence or limited intake of animal products; reduced bioavailability
Chronic Alcoholics	Thiamine (B1), Folate, B12, Vitamin A	Poor diet, malabsorption, impaired metabolism and storage
Digestive Disorders	Fat-soluble vitamins (A, D, E, K), B vitamins	Malabsorption due to intestinal inflammation or damage (e.g., Crohn's, celiac)
Limited Sun Exposure	Vitamin D	Insufficient synthesis from sunlight; lifestyle or geographic factors

Prevention and management strategies

Preventing vitamin deficiencies requires a multi-pronged approach tailored to an individual's specific risk factors. Eating a balanced, nutrient-rich diet is the cornerstone of prevention. Incorporating a variety of fruits, vegetables, whole grains, and lean proteins helps ensure adequate intake of essential vitamins. For those with dietary restrictions or medical conditions, supplementation may be necessary. Consultation with a healthcare provider or a registered dietitian is crucial to determine appropriate dietary adjustments or supplementation protocols.

Public health strategies like food fortification have been highly effective in combating widespread deficiencies, such as folic acid fortification of grains to prevent neural tube defects. Regular health check-ups and diagnostic testing can help identify deficiencies early, allowing for timely and effective treatment.

Conclusion

Multiple segments of the population face distinct risks for vitamin deficiency, driven by factors ranging from natural physiological changes to lifestyle and chronic disease. Older adults, pregnant women, individuals with digestive disorders, those on restrictive diets, and people with limited sun exposure are among the most vulnerable groups. Early identification and management are key to preventing the potentially severe health consequences associated with these nutritional shortfalls. By understanding these specific risks, individuals and healthcare professionals can implement targeted strategies, such as dietary modifications, supplementation, and public health interventions, to ensure adequate vitamin intake and promote long-term well-being. For comprehensive public health guidance on malnutrition, see the World Health Organization's fact sheets.

Frequently Asked Questions

The most common cause is a poor, unbalanced diet that lacks a variety of nutrient-rich whole foods like fruits, vegetables, and lean proteins. Underlying medical conditions, lifestyle choices, and age are also major factors.

Older adults are at higher risk due to decreased appetite, reduced stomach acid affecting B12 absorption, medication interference, and lower skin synthesis of vitamin D.

A vegan diet can lead to deficiencies in vitamin B12, vitamin D, calcium, and iodine, as these nutrients are most readily found in animal products or have lower bioavailability in plant-based sources.

Chronic alcoholism leads to inadequate nutrient intake, impairs the body's ability to absorb, store, and metabolize vitamins, and increases nutrient requirements. This particularly affects B vitamins, folate, and vitamin A.

Yes, conditions like Crohn's, celiac disease, and post-gastric bypass surgery can cause malabsorption, limiting the body's ability to take in nutrients and leading to various deficiencies.

Pregnant women have increased nutritional needs, making them susceptible to deficiencies in vitamins like folate, iron, and B12. These deficiencies can impact fetal development and increase risks for the mother.

Prevention involves a balanced, varied diet rich in whole foods. Supplementation may be necessary for those with restrictive diets or absorption issues. Regular health check-ups and sun exposure (for vitamin D) are also recommended.