Why did rickets mainly occur in children

Rickets and osteomalacia

Brief overview

  • What is rickets or osteomalacia? Disruption of bone metabolism resulting in soft, malleable bones. Called rickets in children and osteomalacia in adults. Another name is "English disease".
  • Symptoms: including muscle and bone pain, muscle cramps, knock knees or bow legs, waddling gait, deformation of ribs (“rickets”) and joints (“Marfan's sign”)
  • root cause: mostly vitamin D deficiency, sometimes a disorder of the vitamin D metabolism (e.g. due to liver disease or gene mutation); vitamin D-independent causes (such as phosphate deficiency) are rare
  • treatment: depending on the cause of rickets. Usually intake of vitamin D and calcium. If necessary, orthopedic aids against skeletal malpositions
  • Prevent: To prevent vitamin D deficiency, stay outdoors daily and eat a diet rich in vitamin D.

What is rickets

Rickets (English disease, rickets) or osteomalacia is a disorder of the bone metabolism. In those affected, the incorporation of calcium and phosphate into the bone tissue is disturbed. If the disease occurs in children, doctors speak of rickets. In adults, however, this bone disease is called osteomalacia.

The most common cause of rickets is vitamin D deficiency. In other cases, a disturbed vitamin D metabolism is the reason for the disease, for example as a result of liver cirrhosis or - rarely - a gene mutation. Vitamin D-independent forms of illness, such as rickets due to phosphate deficiency, are also rare.

Rickets: symptoms

Most of the time they show up first signs of rickets in babies in the second to third month of life. These include:

  • Restlessness
  • Jumpiness
  • Sweating (especially) on the back of the head
  • Baldness on the back of the head

In the third to fourth month of life, further rickets symptoms appear:

  • Muscle weakness (hypotonia)
  • sagging abdominal wall
  • constipation
  • Sensitivity to touch
  • possible signs of neuromuscular over-excitability (tetany), e.g. muscle spasms, paralyzes
  • possibly epileptic seizures

In the foreground are in rickets, however Skeletal changes:

  • abnormally soft, elastic skull bones (craniotabes)
  • Flattening of the occiput and protrusion of the forehead and crown (Caput quadratum = "square skull")
  • Bow-legs or knock-knees
  • Bending of the thigh neck (Coxa vara), which leads to the "waddling gait"
  • Palpable and later also visible swelling of the cartilage-bone boundaries on the ribs ("rickets rosary") and on the joints ("Marfan sign")
  • other bone deformations, e.g. kyphosis (curved backward curvature of the spine), bell-shaped thorax (bell-shaped chest)

With severe changes in the ribs or the thorax, impairment of lung function and diseases of the bronchi are possible.

The rickets is also one of the symptoms of rickets delayed closure of the gaps in the skull (Fontanelles).

In addition, rickets often affects the Teeth noticeable: the milk teeth erupt late. Tooth decay and tooth enamel defects are common.

The most common cause of rickets - vitamin D deficiency - occurs with symptoms such as muscle aches and pains, muscle weakness, muscle spasms and paralyzes. You can read more about this in the article Vitamin D Deficiency.

Osteomalacia: symptoms

The clinical picture in adults - osteomalacia - manifests itself mainly in uncharacteristic bone pain and muscle weakness with the resultant gait disorders (waddling gait). In more pronounced cases, there is also softening and deformation of the boil, especially in the area of ​​the chest, hips and knees (e.g. bow legs).

Osteomalacia, especially in older people, is often accompanied by bone loss (osteoporosis).

Rickets: causes and risk factors

Vitamin D deficiency

The most common cause of rickets is vitamin D deficiency. This is mainly caused by the fact that the skin is not exposed to enough sunlight. The body can cover around 80 percent of its vitamin D requirement through its own production: Under the action of UV radiation, the effective vitamin is created from precursors in the skin.

The body absorbs the remaining 20 percent of the required amount of vitamin D through food.

Thus, there are essentially the following risk factors for a vitamin D deficiency and thus also for a vitamin D deficiency rickets:

  • Insufficient exposure to the sun (e.g. if you are bedridden for a long time, nursing home residents, people who wear medals or chador, people with dark skin who live in an area with little sun exposure)
  • Malnutrition or malnutrition
  • impaired absorption or utilization of vitamin D (e.g. in chronic inflammatory bowel diseases, celiac disease or gastrointestinal operations)

Disorder of the vitamin D metabolism

Disorders in the vitamin D metabolism are another possible cause of rickets. For example, you can use a Liver or kidney disease (such as cirrhosis of the liver, chronic kidney failure).

The disorders in the vitamin D metabolism are seldom congenital. There are two types of hereditary rickets:

  • Vitamin D-dependent rickets type 1 (VDAR I): A gene mutation impairs the activity of an enzyme that converts inactive vitamin D into its active form.
  • Vitamin D-dependent rickets type 2 (VDAR II): Mutations in the gene for the vitamin's docking point (vitamin D receptor) impair the vitamin's effectiveness.

Vitamin D-independent causes

Forms of rickets that have developed independently of vitamin D are also rare. One of them is the so-called hypophosphatemic rickets (also called vitamin D-resistant rickets). It is mostly based on a congenital genetic defect, which is why it is also referred to as hereditary (hereditary) hypophosphatemic rickets. The genetic defect means that too much phosphate is excreted through the kidneys. The result is a phosphate deficiency that damages the bones - the body depends on sufficient phosphate for their structure.

Rarely does hypophosphatemic rickets - or, in adults, hypophosphatemic osteomalacia - develop in association with a tumor. This can be, for example, a so-called giant cell tumor of the bones, but also prostate cancer or breast cancer. One then speaks of tumor-induced rickets or osteomalacia.

Rickets: examination and diagnosis

If your child is suspected of having rickets, you should see a pediatrician. Adults should first contact their general practitioner if there are any signs of osteomalacia. He can classify the symptoms and refer the patient to a specialist if necessary.


The first step towards diagnosis is a detailed interview to collect the medical history (anamnesis). The doctor asks the following questions, for example:

  • Do you / your child stay outdoors regularly?
  • Do you or your child eat a vegetarian or vegan diet?
  • Do you or does your child take food supplements?
  • Is there bone pain?
  • Have you noticed any changes to the skeleton?

A thorough anamnesis can lead to the suspicion of rickets or osteomalacia. However, further examinations are necessary for a reliable diagnosis.

Physical examination

The next step is the physical exam. The doctor primarily examines the patient's posture, gait and bones. In children, palpation of the fontanelles (cracks in the bones in the child's skull) can provide another indication of rickets: In rickets, a delayed closure of the fontanelles is observed (the gaps in the skull ossify later than normal).

Laboratory values

Various laboratory values ​​are very important when clarifying rickets or osteomalacia. The following blood values ​​are decisive:

  • phosphate
  • calcium
  • alkaline phosphatase (AP)
  • Parathyroid hormone (PTH): a thyroid hormone
  • Calcidiol: storage form of vitamin D in the body; chemical formula: 25-OHD
  • Calcitriol: activated form of vitamin D; chemical formula: 1,25- (OH) 2D

The levels of the various blood values ​​and their relationship to one another indicate the cause of the rickets / osteomalacia. This is important because the different forms of rickets sometimes have to be treated differently.

For example, there is a combination of normal phosphate levels and increased values ​​for AP and PTH both in vitamin D deficiency rickets and in the hereditary forms of rickets VDAR I and VDAR II. In the latter two, however, the calcidiol level is normal , while it is lowered in vitamin D deficiency rickets.

In order to differentiate between VDAR I and VDAR II, the doctor looks at the calcitriol level: In VDAR I it is lowered, in VDAR II it is increased.


The doctor can also take x-rays to confirm the diagnosis. This shows the bone changes characteristic of rickets. In addition, the images allow an assessment of the bone density.

Further investigations

Other examinations may be useful in individual cases. For example, in unclear cases of osteomalacia, sometimes a Bone biopsy carried out, i.e. some bone tissue was removed and analyzed in the laboratory.

If the doctor suspects a tumor to be the cause of osteomalacia (tumor-induced osteomalacia), a Magnetic resonance imaging (Magnetic resonance imaging, MRI) may be necessary to track down the tumor.

Read more about the examinations

Find out here which examinations can be useful for this disease:

Rickets: treatment

The treatment of rickets or osteomalacia depends primarily on the cause of the disease and the age of the patient.

Treatment of vitamin D deficiency rickets

If a vitamin D deficiency is the cause of rickets, it is important to compensate for it with medication. The children receive vitamin D and additional calcium, whereby the dosage depends on the age at which the diagnosis is made (IU = "international unit"):

  • 1st year of life: 2000 IU vitamin D3 and 40 to 80 mg calcium per kilogram of body weight and day for 12 weeks. Thereafter, up to the end of the 1st year of life, 500 IU vitamin D3 per day as prophylaxis.
  • 1 to 12 years: 3000 to 6000 IU vitamin D3 and at least 500 mg calcium per day for 12 weeks.
  • From 12 years: 6000 IU vitamin D3 and 500 to 1000 mg calcium per day for 12 weeks.

A blood test is recommended three to four weeks after the start of therapy in order to adjust the dose of vitamin D or calcium if necessary.

Risk groups should generally take 500 IU of vitamin D per day. This includes only breastfed infants, the chronically ill, children / adolescents who take medication for epilepsy, and migrants with dark skin.

Further measures

If you experience cramping or sensory disturbances such as tingling or numbness due to low calcium levels Calcium as an infusion administered. As soon as the condition of those affected improves, the trace element should be administered orally (e.g. as an effervescent tablet) as soon as possible - if the calcium level is still too low.

When taking high doses of vitamin D, it is imperative that you also consume sufficient calcium. Otherwise, there is initially a risk of a seizure as a result of a sharp drop in calcium levels.

If the soft bones lead to malpositions such as knock knees or bow legs or scoliosis, can orthopedic aids become necessary. These include, for example, shoe insoles that compensate for an axial misalignment or a corset for an upright posture. Discuss the correct treatment with the pediatrician or an orthopedic surgeon.

Treatment of other forms of rickets

Patients with hypophosphatemic rickets or osteomalacia need to take phosphate and active vitamin D (calcitriol). However, if the softening and deformation of the bone can be attributed to a tumor disease, it is sometimes sufficient to remove the tumor. However, if the condition of the bones does not improve afterwards, treatment with phosphorus and calcitriol will be necessary.

Therapy for the hereditary form of rickets VDAR I consists of lifelong, daily intake of calcitriol or alpha-calcidiol. Calcium is also given in the first few months of therapy.

Patients with VDAR II receive high doses of calcitriol and calcium. If this treatment is unsuccessful, an attempt can be made with high doses of calcium.

Rickets: course and prognosis

If the most common form of rickets - vitamin D deficiency rickets - is detected and treated, the laboratory values ​​normalize after a few weeks. The skeletal changes that can be seen on the X-ray images regress after weeks to months. Misalignments of the leg axes (e.g. bow legs), as they are often observed in rickets patients, usually do not require an operation (osteotomy), but mostly straighten themselves. However, this can take two to three years.

Prevent rickets

In order to prevent rickets or osteomalacia, it is especially important to prevent the most common cause - vitamin D deficiency. In addition, one should make sure that there is enough daylight for the vitamin D synthesis in the skin. How much “sufficient” means depends, among other things, on your own skin type, the season and the geographical latitude. You can find more detailed recommendations on this in the article Vitamin D Deficiency.

Diet also makes a small contribution to the vitamin D supply. Larger amounts of the vitamin are found in fish, liver and dairy products, for example. You can find out more about this in the article Vitamin D - Foods with a high content.

Vitamin D prophylaxis

In some cases, sun exposure and diet are insufficient to meet vitamin D needs. Then it can make sense to take vitamin D as a supplement (e.g. in the form of tablets or drops).

Such vitamin D prophylaxis should only be carried out in consultation with a doctor. He can do a blood test to find out whether you should be taking a vitamin D supplement, and if so, in what dose. Be sure to stick to the recommended dose to avoid overdosing. If you take too much vitamin D out of concern about a vitamin D deficiency and its consequences (such as rickets or osteomalacia), you can develop kidney stones or calcification of the kidneys, for example.

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