What are three examples of deficiency diseases?

January 9, 2026 •

4 min read

According to the World Health Organization, malnutrition in all its forms, including micronutrient deficiencies, is one of the greatest global health challenges. Understanding what are three examples of deficiency diseases—namely scurvy, rickets, and beriberi—sheds light on the critical role specific vitamins play in human health.

Quick Summary

Scurvy is a vitamin C deficiency causing fatigue and bleeding gums, while rickets results from a lack of vitamin D, leading to soft bones in children. Beriberi is caused by thiamine (vitamin B1) deficiency and affects the nervous and cardiovascular systems.

Key Points

Scurvy Causes Bleeding Gums: A severe, chronic lack of vitamin C is the cause of scurvy, leading to weakened collagen and symptoms like bleeding gums and poor wound healing.
Rickets Weakens Bones: Primarily affecting children, rickets is caused by insufficient vitamin D, leading to improper calcium absorption and soft, weakened bones.
Beriberi Affects Nerves and Heart: Beriberi results from a thiamine (vitamin B1) deficiency, damaging the nervous and cardiovascular systems, causing symptoms like confusion, weakness, and rapid heart rate.
Balanced Diet is Key to Prevention: A diet rich in fresh fruits, vegetables, whole grains, and fortified foods is the most effective way to prevent these and other deficiency diseases.
Global Malnutrition Still Exists: Despite being rare in many developed countries, malnutrition and micronutrient deficiencies, including these diseases, remain a significant global health challenge, especially in low-income regions.
Symptoms Can Vary by Age: The manifestation of deficiency diseases can differ significantly between infants, children, and adults, as seen in rickets versus osteomalacia.

Scurvy: A Severe Vitamin C Deficiency

Scurvy is a disease caused by a severe, prolonged deficiency of vitamin C, also known as ascorbic acid. While it was historically associated with sailors on long voyages, it still occurs today in populations with poor nutritional intake, such as older adults on restrictive diets, those with alcohol use disorder, and individuals with malabsorption issues. Vitamin C is vital for the synthesis of collagen, a crucial structural protein found in connective tissues, skin, and blood vessels.

Causes of Scurvy

Scurvy arises from a sustained dietary lack of vitamin C, typically over a period of at least three months. Contributing factors include:

Inadequate Diet: Not consuming enough fresh fruits and vegetables.
Cooking Methods: Vitamin C is sensitive to heat, and prolonged cooking can destroy it.
Increased Requirements: Conditions like pregnancy, breastfeeding, chronic illness, and smoking increase the body's need for vitamin C.

Symptoms and Treatment of Scurvy

Early symptoms often include general weakness, fatigue, and irritability. As the deficiency worsens, more serious signs develop, including:

Swollen, spongy, and bleeding gums.
Loosened teeth that may fall out.
Easy bruising and small red or blue spots on the skin (petechiae).
Joint pain and swelling.
Poor wound healing.
Dry, scaly skin and coiled body hair.

Scurvy is treated effectively with vitamin C supplementation and by increasing consumption of fresh fruits and vegetables rich in vitamin C, such as citrus fruits, peppers, and strawberries.

Rickets: The Result of Vitamin D Deficiency

Rickets is a condition affecting bone development in children, causing their bones to soften and weaken. The most common cause is a severe deficiency of vitamin D, which is essential for the body to absorb calcium and phosphorus from food. The adult equivalent of this condition is known as osteomalacia.

Causes of Rickets

Insufficient Sun Exposure: The body produces vitamin D when skin is exposed to sunlight. Children who spend little time outdoors or live in areas with minimal sunlight are at risk.
Dietary Lack: Limited dietary intake of vitamin D from sources like fatty fish, eggs, and fortified foods can contribute to deficiency.
Maternal Deficiency: Babies born to mothers with a severe vitamin D deficiency are at risk.

Symptoms and Treatment of Rickets

Symptoms of rickets primarily affect the skeletal system and include:

Bowed legs or knock-knees.
Bone pain and tenderness in the spine, legs, and pelvis.
Delayed growth and development.
Weak muscles.
Skeletal deformities in the skull and ribcage.

Treatment involves vitamin D and calcium supplements, along with dietary changes and increased, but safe, sun exposure. In some cases, corrective braces or surgery may be required for severe skeletal deformities.

Beriberi: The Thiamine (B1) Deficiency Disease

Beriberi is caused by a deficiency of thiamine, or vitamin B1. The body needs thiamine to metabolize food for energy, and its deficiency can damage the nerves, muscles, and heart. There are two primary types: dry beriberi, which affects the nervous system, and wet beriberi, which impacts the cardiovascular system.

Causes of Beriberi

Poor Diet: Diets consisting primarily of processed, unenriched white rice or highly refined carbohydrates are a classic cause, as milling removes thiamine.
Alcohol Misuse: Alcoholism can hinder the body's ability to absorb and store thiamine.
Medical Conditions: Conditions like bariatric surgery, prolonged diarrhea, and certain genetic disorders can cause a deficiency.

Symptoms and Treatment of Beriberi

Symptoms vary depending on the type:

Dry Beriberi Symptoms: Muscle weakness, tingling or numbness in the limbs, pain, confusion, and difficulty walking.
Wet Beriberi Symptoms: Shortness of breath, rapid heart rate, and swelling of the lower legs due to fluid accumulation.

Treatment involves thiamine supplementation, which can be administered orally or via injection in severe cases. Dietary changes to include thiamine-rich foods like whole grains, fish, and legumes are essential for prevention.

Comparison of Deficiency Diseases


Feature	Scurvy	Rickets	Beriberi
Deficiency	Vitamin C (Ascorbic Acid)	Vitamin D	Vitamin B1 (Thiamine)
Affected System	Connective tissues, immune system, skin	Skeletal system, bones	Nervous system, cardiovascular system
Key Symptoms	Bleeding gums, fatigue, poor wound healing, bruising	Bowed legs, bone pain, muscle weakness, stunted growth	Neurological symptoms (confusion, tingling) or cardiovascular issues (rapid heart rate, swelling)
Primary Cause	Lack of fresh fruits and vegetables	Insufficient sun exposure and/or dietary intake	Diet of refined grains, alcohol misuse

Conclusion

Scurvy, rickets, and beriberi are stark examples of how a lack of specific vitamins can have profound effects on the body. While these conditions are rare in many developed nations due to food fortification and improved nutrition, they serve as a powerful reminder of the importance of a balanced diet rich in essential nutrients. The long-term impacts, particularly on children, can be severe if left untreated, reinforcing the need for adequate nutrition from conception onward. For more information on global malnutrition, visit the World Health Organization's website.

Frequently Asked Questions

The main cause of beriberi is a diet severely lacking in thiamine, or vitamin B1. It is often associated with the consumption of polished white rice, which has had the thiamine-rich outer layer removed.

Scurvy is treated with vitamin C supplements and by increasing the consumption of foods rich in vitamin C, such as citrus fruits, strawberries, broccoli, and peppers.

Rickets and osteomalacia are both caused by a vitamin D deficiency. The difference is that rickets affects children, leading to bone deformities like bowed legs, while osteomalacia affects adults, causing soft, weakened bones and chronic pain.

A deficiency of vitamin D causes rickets in children, which can lead to weakened bones, bone pain, and skeletal deformities such as bowed legs or knock-knees.

Yes, beriberi can affect the heart. The form known as 'wet beriberi' damages the cardiovascular system and can lead to symptoms such as rapid heart rate, shortness of breath, and swelling in the legs.

In many developed countries with access to fortified foods, severe deficiency diseases like scurvy and beriberi are rare. However, milder deficiencies are more common, and these conditions still occur in at-risk populations and in low-income countries.

The best way to prevent vitamin deficiencies is by maintaining a healthy, balanced diet with a variety of fruits, vegetables, and whole grains. In some cases, supplements may be recommended by a healthcare professional.