Osteomalacia is also known as bone softening. It is a condition in which new bone does not harden the way it should after forming.

This condition can affect people of all ages because everyone’s bones are constantly going through a process called bone turnover.

Bone turnover is when the body reabsorbs the old tissue and forms new bone tissue, starting with the softer inner layer that comprises collagen.

In another process called mineralization, this inner layer normally becomes coated with minerals that form a hard outer shell. When people have osteomalacia, the shell does not form fully, leaving the collagen soft and vulnerable.

In this article, we explore the causes, symptoms, diagnosis, treatment, and complications of osteomalacia. We also discuss the outlook for people with this condition.

an X-ray photograph showing an arm suffering from osteomalaciaShare on Pinterest
Image credit: Leslie Gamache, Mark R. Burge, 2014.

One of the key differences between osteomalacia and rickets is the age of the people that these conditions typically affect.

Rickets only develops in children whose bones are still growing, whereas osteomalacia can develop in people of all ages.

Rickets can cause deformed bones in children and limit their growth, while deformities usually only occur in severe cases of osteomalacia.

Osteoporosis is a disease in which the balance between bone loss and bone formation becomes disrupted, resulting in bone thinning and weakening and an increased risk of broken bones.

With osteomalacia, the problem is not bone loss. Instead, people with this condition have soft bones due to incomplete mineralization, which is part of the process of bone formation.

The most common cause of the incomplete mineralization that leads to osteomalacia is low levels of vitamin D. Other possible causes include:

  • lack of phosphorus
  • celiac disease
  • kidney problems
  • liver disorders
  • genetic factors

When a person has low levels of vitamin D, it may be because they are not taking in enough of this nutrient, or their body is not able to absorb it.

Reasons why people do not take in enough vitamin D include:

  • diets that are low in vitamin D-rich foods, such as oily fish, egg yolks, and fortified foods
  • living in areas where there is not much natural sunlight
  • having darker skin, which does not absorb vitamin D as readily as lighter skin
  • wearing clothing that fully covers the body and keeps the skin from getting exposure to sunlight

Along with underlying conditions, additional factors that can make it difficult for people to absorb vitamin D include:

The symptoms of osteomalacia include:

  • pain in the legs, upper thighs, and knees
  • weak, sore, and stiff muscles, especially in the trunk, shoulders, buttocks, and upper legs
  • difficulty walking
  • bones that can be sensitive to slight knocks
  • muscle spasms
  • pseudofractures of weight-bearing bones, such as the feet and pelvis

Some individuals may not have any symptoms.

The most common symptoms of osteomalacia, such as sore bones and muscles, are vague enough that it can sometimes take 2–3 years to diagnose the condition.

However, once a doctor suspects osteomalacia, several different tests can help them diagnose it.

It may take more than one type of test to provide conclusive results. A doctor may analyze blood and urine samples to look for:

  • low levels of calcium
  • low levels of phosphate
  • high levels of parathyroid hormones
  • high levels of alkaline phosphatase

They might also use X-rays and bone density tests to aid the diagnosis.

One of the most important aspects of osteomalacia treatment is to make sure that a person gets the levels of nutrients they need to support the bone mineralization process.

Taking therapeutic dosages of supplements, such as vitamin D or phosphate, is a common treatment strategy.

Some experts recommend taking 6,000 international units (IU) of vitamin D3 daily for an 8-week period to treat vitamin D deficiency.

Additional approaches to the promotion of strong, healthy bones include:

  • taking vitamin D, calcium, and phosphorus supplements on an ongoing basis
  • getting regular exposure to sunlight, while taking precautions to avoid damage from the sun
  • stopping smoking, if a smoker
  • limiting the intake of alcohol
  • exercising regularly
  • eating a healthful diet rich in foods containing vitamin D and calcium

To prevent rickets or osteomalacia in children, experts recommend daily doses of 600 IU vitamin D and dietary calcium in pregnant people and 400 IU daily in infants from birth.

The federal government’s recommended daily allowance for vitamin D is 600 IU a day for people between the ages of 1 and 70 years, after which it goes up to 800 IU a day.

Without treatment, the symptoms of osteomalacia can worsen.

Pseudofractures, also known as Looser’s zones, can appear, and they can cause pain and turn into real breaks.

The outlook for people with osteomalacia is very good when they receive treatment, although it can take months to make a complete recovery.

When a person has osteomalacia, their newly formed bones do not mineralize, or harden, as they should. Without their hard outer layer, bones are soft and sensitive to the touch.

Along with the pain and discomfort that this causes, osteomalacia increases the risk of bone fractures. Therefore, it is more likely that a person will develop deformed bones.

Treatment for this condition calls for prescription-strength dosages of vitamin D and, in some cases, the use of supplements on an ongoing basis.

Treatment is generally effective, although it can take months for bone strength to return in full.

Read this article in Spanish.