What is vitamin D deficiency in children known as and in adults?

December 11, 2025 •

3 min read

According to the Cleveland Clinic, Vitamin D deficiency is a common health issue affecting individuals of all ages. In children, this condition is known as rickets, while in adults, it is called osteomalacia, both causing weakened bones and other health problems.

Quick Summary

Vitamin D deficiency causes rickets in children, resulting in softened bones, skeletal deformities, and pain, and leads to osteomalacia in adults, which is characterized by soft bones and muscle weakness.

Key Points

Rickets in Children: Vitamin D deficiency causes rickets in children, resulting in soft, weakened, and misshapen bones due to defective mineralization at the growth plates.
Osteomalacia in Adults: In adults, the same deficiency is known as osteomalacia, which causes softening of existing bone and leads to chronic bone pain, muscle weakness, and an increased risk of fractures.
Causes of Deficiency: Inadequate sun exposure, insufficient dietary intake, malabsorption disorders, certain medications, obesity, and age are common causes of vitamin D deficiency.
Diagnosis and Treatment: Diagnosis involves blood tests to measure 25-hydroxyvitamin D levels, with treatment including supplements, dietary adjustments, and controlled sun exposure.
Preventable Conditions: Both rickets and osteomalacia are largely preventable and treatable, but early intervention is crucial to avoid long-term complications like permanent skeletal deformities in children.
Importance of Supplements: For many high-risk individuals, including exclusively breastfed infants and older adults, supplementation is a necessary and effective way to maintain adequate vitamin D levels.

The Importance of Vitamin D

Vitamin D is crucial for absorbing calcium and phosphorus, vital for strong bones. It's obtained from sun exposure, certain foods, and supplements. Insufficient vitamin D impairs bone mineralization, leading to age-specific disorders. The different names for the deficiency in children and adults reflect how it impacts developing versus mature bones.

Rickets: Vitamin D Deficiency in Children

In children, vitamin D deficiency is called rickets, affecting bone development during growth. This causes bones to soften, weaken, and deform due to poor mineralization at growth plates.

Symptoms of Rickets in Children

Rickets symptoms vary, including:

Bowed legs or knock-knees
Thickened wrists and ankles
Delayed growth
Bone pain
Muscle weakness and delayed motor skills
Dental issues
Seizures in severe cases due to low calcium

Causes and Risk Factors for Rickets

Low Sun Exposure: Risk factors include living in northern latitudes, limited outdoor time, or having darker skin.
Poor Diet: Exclusive breastfeeding without supplements is a risk due to low vitamin D in breast milk.
Maternal Deficiency: Can lead to infants being born with or developing rickets.
Health Conditions: Liver, kidney, or intestinal diseases can hinder absorption or activation.

Osteomalacia: Vitamin D Deficiency in Adults

Adults with vitamin D deficiency develop osteomalacia, meaning "soft bones". This occurs after growth plates close and involves poor mineralization of new bone during remodeling, resulting in weak, fracture-prone bones.

Symptoms of Osteomalacia in Adults

Symptoms can be subtle initially but include:

Persistent bone pain, often in the lower back, hips, and legs
Muscle weakness, affecting gait
Increased fracture risk
Difficulty walking
Muscle cramps due to low calcium

Causes and Risk Factors for Osteomalacia

Lack of Sun Exposure: Similar to children, limited sun exposure is a risk, affecting those who are homebound, institutionalized, or in higher latitudes.
Malabsorption: Digestive disorders like celiac disease or Crohn's can impair vitamin D and calcium absorption.
Aging: The skin's ability to produce vitamin D from sunlight declines with age.
Obesity: Excess body fat can store vitamin D, making it less available.
Medications: Some drugs, like anti-seizure medications, can increase vitamin D breakdown.

Rickets vs. Osteomalacia: A Comparison


Feature	Rickets (Children)	Osteomalacia (Adults)
Affected Population	Infants, children, and adolescents	Adults after bone growth has ceased
Pathophysiology	Failure of mineralization at the growth plates	Defective mineralization of new bone (osteoid) during remodeling
Primary Manifestation	Skeletal deformities, such as bowed legs	Bone and muscle pain, increased fracture risk
Effect on Bones	Softens and weakens growing bones	Softens existing, mature bones
Growth Plates	Remains open and unmineralized, leading to widening	Closed, so no growth plate abnormalities occur

Diagnosis and Treatment of Deficiency

Diagnosing vitamin D deficiency involves a blood test to measure 25-hydroxyvitamin D levels. Blood tests may also check calcium, phosphorus, and parathyroid hormone.

Treatment focuses on restoring vitamin D levels:

Supplementation: High-dose supplements are often needed initially, followed by a maintenance dose.
Dietary Changes: Increase intake of vitamin D-rich foods like fatty fish and fortified products.
Controlled Sun Exposure: Limited, unprotected sun exposure can help, but balance with skin cancer risks.

Conclusion

Recognizing vitamin D deficiency as rickets in children and osteomalacia in adults is crucial for treatment. Both stem from low vitamin D but manifest differently due to age and bone development stage. Rickets causes deformities in children, while osteomalacia leads to pain and fragility in adults. Treatment with supplements, diet, and controlled sun exposure is key to prevention and managing these conditions, ensuring lifelong bone health.

For more detailed medical information, refer to the Vitamin D Fact Sheet from the National Institutes of Health.

Potential Complications of Vitamin D Deficiency

Untreated deficiency can lead to complications beyond weak bones:

Chronic Pain: Severe bone pain impacting life quality.
Fractures: Higher risk of broken bones.
Skeletal Deformities: Potential for permanent deformities in children.
Muscle Problems: Progressive weakness and cramps.
Other Health Issues: Possible links to autoimmune diseases, certain cancers, and cardiovascular issues.

Prevention is vital, especially for high-risk groups like the elderly, those with darker skin, limited sun exposure, and malabsorption issues. Awareness and medical advice are key to managing vitamin D levels and protecting health.

Frequently Asked Questions

In children, vitamin D deficiency is specifically known as rickets, a condition that leads to the softening and weakening of the bones.

In adults, vitamin D deficiency is called osteomalacia, which results in soft bones and can cause bone pain and muscle weakness.

They have different names because they affect the bones at different stages of life. Rickets impacts the developing bones and growth plates of children, while osteomalacia affects the bone remodeling process in mature adult bones.

Key symptoms of rickets in children include bowed legs, delayed growth, bone pain, and thickened ankles and wrists due to the softening of the growth plates.

Common symptoms in adults include persistent, aching bone pain, especially in the hips and lower back, as well as muscle weakness and an increased risk of fractures.

Treatment for vitamin D deficiency typically involves supplements to restore adequate levels, combined with increased dietary intake of vitamin D-rich foods and some controlled sun exposure.

Higher risk groups include infants who are exclusively breastfed, older adults, individuals with darker skin, people with limited sun exposure, and those with certain medical conditions like malabsorption disorders.