Osteomalacia is softening of the bones. It occurs because of a lack of vitamin D or a problem with the body's ability to break down and use this vitamin, which helps your body absorb calcium. Your body needs calcium to maintain the strength and hardness of your bones.
Bones that have softened due to osteomalacia have a normal amount of collagen, which gives structure to the bones. However, the bones lack the proper amount of calcium to keep them hard.
There are many causes of osteomalacia. In children, the condition is called rickets. It is most often caused by a low level of vitamin D.
Other conditions that may lead to osteomalacia include:
- Not enough vitamin D in the diet
- Not enough exposure to sunlight, which produces vitamin D in the body
- Malabsorption of vitamin D by the intestines
Factors that interfere with the body's ability to form vitamin D include:
- Having very little exposure to sunlight
- Shorter days of sunlight
- Using very strong sunscreen
Elderly people and people who do not drink milk are at higher risk for osteomalacia.
Other conditions that may cause osteomalacia include:
- Disorders of vitamin D metabolism
- Kidney failure and acidosis
- Lack of enough phosphates in the diet
- Liver disease
- Side effects of medications used to treat seizures
- Bone fractures that happen without a real injury
- Muscle weakness
- Widespread bone pain, especially in the hips
Symptoms may also occur due to low calcium levels. These include:
Exams and Tests
Blood tests will be done to check vitamin D, creatinine, calcium, phosphate, electrolytes, alkaline phosphatase and parathyroid hormone levels.
In some cases, a bone biopsy will be done to see if bone softening is present.
Treatment may involve vitamin D, calcium, and phosphorus supplements taken by mouth. People who cannot absorb nutrients well through the intestines may need larger doses of vitamin D and calcium.
People with certain conditions may need regular blood tests to monitor blood levels of phosphorus and calcium.
Some people with vitamin deficiency disorders will get better within a few weeks. With treatment, healing should happen within 6 months.
Symptoms can return.
When to Contact a Medical Professional
Call your health care provider if you have symptoms of osteomalacia, or if you think that you may be at risk for this disorder.
Eating a diet rich in vitamin D and getting plenty of sunlight and calcium can help prevent osteomalacia due to a vitamin D deficiency.
Lorenzo JA, Canalis E, Raisz LG. Metabolic bone disease. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 29.
Sysolmerski JJ, Insogna KL. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 253.
Reviewed By: Gordon A. Starkebaum, MD, Professor of Medicine, Division of Rheumatology, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.