Rickets is a condition that affect bone development in children. It is lead to softening and weakening of the bones. Nutritional, hereditary, renal rickets are the subtypes of rickets.

Several causes of rickets are lack of vitamin D, calcium or phosphorous, problems with absorption such as celiac disease is a digestive disorder caused by an abnormal immune reaction to gluten, inflammatory bowel disease, and cystic fibrosis is a genetic lung disorder that affects the pancreas and other organs.

Dark skin, geographical location, and Babies born to a mother with severe vitamin D deficiency or born before their due dates are at higher risk of rickets.

Rickets in immature bones occurs when parathyroid hormone (PTH ) is activated by a certain sequence of events and enables it to perform certain functions, which decrease bone mineralization and prevent apoptosis of hypertrophied chondrocytes, leading to disorganized growth plate cartilage. 

Delayed growth, pain or tenderness in the arms, spine, pelvis and legs, muscle weakness, dental problems, skeletal deformities such as a thickening of the ankles, wrists and knees, bowed legs, soft skull bones, and breastbone projection, and among other symptoms .

Rickets can be diagnosed by several ways, include physical exam such as gently press on child's bones, checking for abnormalities for specific regions by the doctor, lab tests such as arterial blood gases, serum calcium, serum phosphorus , serum alkaline phosphatase , and bone X-rays.

Relieve symptoms and correct the cause of the condition are the goals of treatment . can be treatment of rickets by several ways, include vitamin D, calcium, or phosphorus supplements, surgical and other procedures, and using a combination of phosphate supplements and a special form of vitamin D .

If untreated rickets, can lead to several complications, such as a chronic skeletal pain, skeletal fractures may occur without cause, skeletal deformities such as abnormally curved spine, and seizures which that abnormal electrical activity in the brain.

However, can be preventing rickets by several steps, include dietary sources of vitamin D and calcium include fish oil and milk, exposure to moderate amounts of sunlight ,  taking daily calcium and vitamin D supplements ,  and having a vitamin D injection each year.

Rickets may be treated by replacing vitamin D and minerals. Large doses of minerals and vitamin D may require in some cases.

According to published study in the centers for disease control and prevention (CDC), five per one million children aged between six months and five years have rickets.

Rickets is a disorder that is caused by a deficiency of vitamin D, calcium, or phosphorous. it affects bone development in children, and lead to soft and weak bone and may bone deformities. 

There are several subtypes of rickets, include:

• Nutritional rickets: is caused by dietary deficiency of vitamin D, calcium, or phosphate.
• Hereditary rickets: A genetic defect is the main cause for this kind of rickets, occurring when kidneys unable to hold onto phosphate, and known as hypophosphatemic rickets. 
• Renal rickets:  is caused due to kidney damage or some form of kidney disease, which prevents the kidneys from functioning normally.  

Usually, rickets disorder occurs due to lack of vitamin D, calcium or phosphorous, although it can also be caused by a genetic defect or another health condition.

• Lack of vitamin D, calcium, and phosphorous

The most common cause of rickets is a lack of vitamin D, calcium or phosphorous in a child's.  Vitamin D and calcium are essential for children to develop strong and healthy bones. Vitamin D is absorbed from food or produced by the skin when exposed to sunlight. 

• Problems with absorption

Developing of medical condition or born with medical condition in some children, that lead to rickets. Some examples of medical condition, including: 

1-Celiac disease.

2-Inflammatory bowel disease.

3-Cystic fibrosis.

4-Kidney problems .

 There are several factors that can increase a child's risk of rickets include:

• Dark skin.

Dark skin does not react as strongly to sunshine as does lighter skin, so it produces less vitamin D.

• Mother's vitamin D deficiency during pregnancy.

 A baby born to a mother with severe vitamin D deficiency can be born with signs of rickets or develop them within a few months after birth.

• geographical locations.

Children who live in geographical locations where there is less sunshine are at higher risk of rickets. 

• Premature birth.

Babies born before their due dates are more likely to develop rickets.

• Medications.

Certain types of anti-seizure medications and antiretroviral medications, used to treat HIV infections, appear to interfere with the body's ability to use vitamin D.

• Exclusive breast-feeding.

Breast milk does not contain enough vitamin D to prevent rickets. Babies who are exclusively breast-fed should receive vitamin D drops. 

• Medical condition

People with lactose intolerant (have trouble digesting milk products) may increase risk of developing rickets. 

• Diet

People with vegetarian diet may increase risk of developing rickets. 

• Genetic defect

Rare forms of rickets can also occur in some inherited disorders. For example, hypophosphatemic rickets is a genetic disorder where the kidneys and bones deal abnormally with phosphate.  Hard bone and teeth that a result from binding phosphate to calcium. This leaves too little phosphate in the blood and bones, leading to weak and soft bones. Other types of genetic rickets affect certain proteins that are used by vitamin D in the body. 

Calcium reabsorption decreases in a vitamin D deficient state lead to low ionized calcium levels and that stimulate secretion of parathyroid hormone (PTH). In the renal tubules, PTH stimulates calcium reabsorption, activity of 1-alpha-hydroxylase leads to increased synthesis of 1,25-OH vitamin D ,and phosphate loss in the urine. Together, these decrease bone mineralization and prevent apoptosis of hypertrophied chondrocytes, leading to disorganized growth plate cartilage.  The clinical presentation is termed rickets in immature bones. 

Signs and symptoms of rickets can include: 

• Delayed growth, the skeleton does not grow and develop properly.
• Pain or tenderness in the arms, spine, pelvis and legs.
• Muscle weakness.
• Skeletal deformities such as a thickening of the ankles, wrists and knees, bowed legs, soft skull bones, and breastbone projection.
• Dental problems that including weak tooth enamel, delayed tooth formation, defects in the tooth structure and increased risk of cavities.
• Fragile bones -the bones become weaker and more prone to fractures, in severe cases.
• Muscle cramps.
• Short stature.

Several ways to help make a rickets diagnosis, including:

• physical exam

A physical exam reveals tenderness or pain in the bones, rather than in the joints or muscles. The doctor will gently press on child's bones, checking for abnormalities for these regions:

1. Skull. The doctor will check the baby’s skull for soft spots or signs of a delay in the closure of the soft spots (fontanels).
2. Legs. Doctors usually check for an exaggerated bowing of the legs, as it is very common in toddlers with rickets.
3. Chest. The doctor will check development of abnormalities in children rib cages, which can flatten and cause their breastbones to protrude.
4. Wrists and ankles. Children who have rickets often have larger or thicker wrists and ankles than normal. 

• Lab tests

The following tests may help diagnose rickets:

1. Arterial blood gases.
2. Serum calcium.
3. Serum phosphorus.
4. Serum alkaline phosphatase (ALP).
5. Calcium (ionized).
6. Parathyroid hormone (PTH).
7. Urine calcium.
8. ALP isoenzyme. 

• Bone x-rays

X-rays of the affected bones can reveal bone deformities.

• Bone biopsy

In rare cases, a bone biopsy will be performed which that removal a small section of bone and analysis it. 

Treatment depends on the type of rickets. Relieve symptoms and correct the cause of the condition are the goals of treatment, the cause must be treated to prevent the disease from returning. 

• Vitamin D, calcium, or phosphorus supplements

Replacing vitamin D, calcium, or phosphorus that is lacking to eliminate most symptoms of rickets.

• Surgical and other procedures 

Some skeletal deformities such as bowed legs or curvature of the spine, may require surgery to correct them, positioning or bracing may be used to reduce or prevent deformities. 

• Treatment of hereditary rickets

Treatment of hereditary rickets by using a combination of phosphate supplements and a special form of vitamin D, where a genetic defect causes abnormalities in the way the kidneys and bones deal with phosphate.

Children with other types of genetic rickets need very large amounts of a special type of vitamin D treatment. 

Left untreated of rickets can lead to several complications , include :

• Chronic skeletal pain. 
• Skeletal fractures may occur without cause. 
• Skeletal deformities such as abnormally curved spine. 
• Seizures. 
• Hypercalcaemia that result from high vitamin D or calcium dose or too long treatment is continued or is not carefully monitored; it can raise calcium levels in the blood. 

There are several steps to monitor levels of Vitamin D and calcium, include:

• • Dietary sources of vitamin D and calcium include fish oil and milk. 
  • Exposure to moderate amounts of sunlight. 
  • Taking daily calcium and vitamin D supplements. 
  • Having a vitamin D injection each year. 

The disorder may be treated by replacing vitamin D and minerals. Large doses of minerals and vitamin D may require in some cases.

Skeletal deformities and short stature may be permanent if untreated rickets while the child is still growing. If it is corrected while the child is young, skeletal deformities often improve or disappear with time. 

According to published study in the centers for disease control and prevention (CDC ), five per one million children aged between six months and five years have rickets.

The frequency of rickets has been increasing internationally. Possible reasons include recommendations for children to wear sunscreen while outdoors and a tendency for children to spend more time indoors, watching television or playing electronic games, instead of playing outdoors.