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Osteomalacia is a disease resulting from a vitamin D shortage in adults. It causes bones to soften and weaken.


Osteomalacia is caused by vitamin D shortage in the body. This may occur when:

  • The supply of vitamin D from diet or sun exposure is too low
  • The way the body processes vitamin D is not typical
  • Tissue does not respond to the action of vitamin D

Vitamin D controls how calcium is absorbed in the body. It also controls levels of calcium and phosphate in bone. Vitamin D is absorbed in the intestines from food. Vitamin D is also produced by the skin during exposure to sunlight.

Most often, osteomalacia is caused by a shortage of vitamin D. This can result from:

  • Not enough vitamin D in the diet
  • Lack of exposure to sunlight

Less often, osteomalacia can be caused by other disorders that affect vitamin D absorption, processing, or action in the body such as:

  • Kidney problems:
    • Renal tubular acidosis—a nonhereditary kidney disorder that causes bone calcium to dissolve
    • Chronic kidney failure
    • Long-term kidney dialysis
  • Diseases of the small intestines with malabsorption
  • Disorders of the liver or pancreas disease
  • Cancer
  • Certain medications such as seizure medication
  • Toxicity or poisoning from:
    • Cadmium
    • Lead
    • Aluminum
  • Outdated tetracycline, an antibiotic

Risk Factors

Osteomalacia is more common in adults 50-80 years of age. It is also more common in people of African American descent.

Factors that can increase your chances of getting osteomalacia include:

  • Lack of sun exposure
  • Lactose intolerance with low intake of vitamin D-fortified milk
  • Family history of rickets


Symptoms may include:

  • Bone pain and tenderness
  • Skeletal and/or skull deformities
  • Bow legs or knock knees
  • Deformity or curvature of the spine
  • Pigeon chest—a chest that protrudes
  • Short stature
  • Susceptibility to bone fractures
  • Dental deformities
  • Defects in teeth
  • Increased cavities
  • Loss of appetite or weight loss
  • Difficulty sleeping
  • Poor muscle development and tone
  • Muscle weakness
Curvature of the Spine
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You will be asked about your symptoms and medical history. A physical exam will be done.

Your bodily fluid and bone may be tested. This can be done with:

  • Blood
  • Urine tests
  • Bone biopsy—when other tests are not conclusive

Pictures may be taken of structures inside your body. This can be done with an x-ray.


Treatment attempts to correct the underlying cause and relieve or reverse symptoms.

Treating the Underlying Cause

Treatment of the underlying cause may include:

  • Increasing your intake of vitamin D by adding:
    • Vitamin D-fortified dairy products
    • Foods high in vitamin D, such as fatty fish, egg yolk, and green vegetables
    • Supplements of vitamin D, calcium, and other minerals
    • Biologically active vitamin D
  • Adequate, but not excessive, exposure to sunlight

Treating Symptoms

Treatment to relieve or correct symptoms may include:

  • Wearing braces to reduce or prevent bony deformities
  • In severe cases, surgery to correct bony deformities


To help prevent osteomalacia:

  • Drink vitamin D-fortified milk.
  • Consume enough vitamin D, calcium, and other minerals. If you think your diet may be deficient, talk with your doctor about alternate sources of vitamins and minerals.
  • Get sufficient, but not excessive, exposure to sunlight. Fifteen minutes a day is usually considered sufficient. Any longer than that requires sun protection with clothing or sunscreens, especially if you have fair skin. People with dark skin may need more sun exposure and dietary supplementation with vitamin D.

Revision Information

  • Academy of Nutrition and Dietetics

  • National Institute of Arthritis and Musculoskeletal and Skin Diseases

  • Bone and Joint Canada

  • Health Canada

  • Grant WB, Boucher BJ. Requirements for Vitamin D across the life span. Biol Res Nurs. 2011;13(2):120-133.

  • Osteomalacia. Arthritis Research UK website. Available at: Accessed January 16, 2015.

  • Osteomalacia. Cleveland Clinic website. Available at: . Updated November 19, 2014. Accessed January 16, 2015.

  • Vitamin D deficiency in adults. EBSCO DynaMed website. Available at: Updated December 29, 2014. Accessed January 16, 2015.