What is rickets?
Rickets is a condition which affects the development of bones in children. Caused in most cases by a deficiency of vitamin D and subsequently also calcium, the condition can lead to the bones becoming soft and weak. This process can ultimately lead to bone deformity if left untreated.
Rickets is most common in children, but its equivalent can also occur in adults. In such cases, the condition is known as osteomalacia or “soft bones”.
Treating rickets generally involves following a nutritionally-balanced diet and/or taking vitamin supplements. In most cases, the condition can be treated successfully.
Symptoms of rickets
- Growth and development issues: Children may be shorter than average due to bone development problems.
- Pain: Bones may become sore or painful, especially when pressure is applied. This may lead to a child being reluctant to walk or get up from a sitting position, and they may appear to walk abnormally.
- Brittle bones: Bones may become weaker than normal, leading to an increased likelihood of fracturing and breaking.
- Dental issues: May include weak tooth enamel, slow development of teeth and an increased likelihood of cavities.
- Deformities: The ankles, wrists and knees may become thicker than normal. Bowed legs, a softening of the skull and – less commonly – a bending of the spine may also occur.
If any of these symptoms are present, medical attention should be sought.
Many of the same symptoms may also occur in adults experiencing osteomalacia. However, adults tend to report more bone pain and tenderness than children with rickets.
Causes of rickets
Rickets can be caused by a variety of factors, including:
- Vitamin D and/or calcium deficiency
- Underlying conditions
Vitamin D and calcium deficiency
A deficiency of vitamin D and/or calcium is by far the most common cause of rickets in children. The majority of children will receive sufficient amounts of calcium through their diet. However, it is rare for one’s diet to contain sufficient quantities of vitamin D, and many people choose to use a vitamin D supplement in order to ensure that they get the required amount.
Foodstuffs containing vitamin D and calcium include:
- Vitamin D: Small quantities of vitamin D are found in oily fish, e.g. salmon, eggs, some dairy products like cheese and some cereals.
- Calcium: Found in dairy products such as cheese, milk and yoghurt, as well as green vegetables such as kale and broccoli.
Vitamin D and calcium supplements are widely available. Consulting a physician when choosing a vitamin supplement is recommended, in order to ensure that it is appropriate for the individual.
Factors that make children more likely to develop rickets related to vitamin D or calcium deficiency include:
- Dark skin: Dark skin contains more melanin than light skin, increasing the amount of UV-B light/sun exposure needed to produce vitamin D.
- Lack of exposure to sun: Children who spend the majority of their time indoors, or lack exposure to sunlight for any other reason, are less likely to produce a sufficient amount of vitamin D. Additionally, if children live in countries that are far away from the equator and/or in the northern hemisphere, even if they spend plenty of time outdoors, the sunlight may not be strong enough to effectively stimulate vitamin D production.
- Pre-existing conditions: Certain conditions – such as liver disease, kidney disease and celiac disease – can affect the way the body produces and controls vitamin D.
- Breastfeeding: Children who are exclusively breastfed and have dark skin and/or a mother who is lacking in vitamin D have a higher chance of developing rickets.
In rare cases, rickets can run in families.
The most common form is hereditary hypophosphatemic rickets, which results from mutations in several genes. This condition renders the kidneys unable to retain phosphate, leading to a deficiency of this important chemical. Phosphate plays a central role in bone formation and growth.
In rare cases, rickets can develop as a result of underlying conditions (some of which are hereditary) of the liver, kidneys or intestines. These conditions typically affect the way the body produces, absorbs and retains minerals and vitamins, and may lead to deficiencies. These include phosphate and calcium deficiencies, which can result in rickets if left untreated.
Diagnosing rickets will generally involve a doctor taking the person’s full medical history, followed by blood tests to check the vitamin D, phosphate, calcium and parathyroid hormone levels. In some cases, blood tests may also be used to check liver and kidney function.
Sometimes, X-rays may also be used to check for skeletal changes or deformity. A dual energy X-ray absorptiometry (DEXA) may also be used to check bone calcium levels.
The necessary treatment route for rickets depends on the condition’s underlying cause.
When rickets is caused by a deficiency of vitamin D or calcium, increasing the intake of each is the primary treatment option. Methods of doing this include:
- Consuming more food rich in vitamin D and calcium, such as oily fish, cereals and eggs for vitamin D, and green leafy vegetables and dairy products for calcium.
- Taking supplements containing vitamin D and calcium.
- Receiving a vitamin D injection (usually administered yearly and, in most cases, only if other options are unavailable).
- Increasing one’s exposure to sunlight.
Treatment for genetic forms of rickets will depend on the type. Hereditary hypophosphatemic rickets (the most common genetic form) typically requires phosphate and vitamin D supplements.
It is rare for vitamin D or calcium supplements to cause any side-effects. However, if an incorrect dose of calcium is given, this can result in a condition known as hypercalcemia. Signs and symptoms include:
- Loss of appetite
- Nausea and/or vomiting
- Abdominal pain
- Thirstiness and an increased need to urinate
- Fatigue and/or weakness
- Muscle pain
If any of these signs or symptoms appear after starting a new supplement, medical attention should be sought without delay.
To ensure one receives the required amount of vitamin D, several measures can be taken:[^10]
- Eating a nutritionally-balanced diet
- Spending time in the sun
- Taking vitamin supplements (after talking to a doctor about the most suitable type and dose)
Maintaining a diet rich in vitamin D and calcium is an effective way of helping to prevent the onset of rickets. Foodstuffs containing these include:
- Vitamin D: Oily fish, eggs, red meat, beef liver and some cereals.
- Calcium: Dairy products including cheese, milk and yoghurt, as well as green vegetables such as kale and broccoli.
Exposure to natural sunlight is a good source of vitamin D. Depending on where a person lives, the time of year, the color of their skin and the clothes they wear, the amount of time needed in the sun will differ. For a person to produce vitamin D, sunlight has to reach the areas of skin that are not covered by clothes.
In a very sunny location in summer, a person may not need much outdoor time daily to produce a healthy amount of vitamin D. The body can produce between 10 000 and 25 000 IU of vitamin D in little less than the time it takes for the skin to start burning. Vitamin D production is maximized when a large area of the skin, such as the back, is exposed.
In many countries in the northern hemisphere, including Germany, the UK, Canada and northern parts of the US, the sun is too weak to produce sufficient amounts of vitamin D between roughly September and March. This means that, even if people spend a lot of time outdoors, it will be necessary to rely on other sources of this vitamin during the winter months.
Although exposure to sunlight is important, it’s also crucial to remember the potential damage sunlight can cause to the skin, especially when sunburn occurs. If spending an extended amount of time exposed to the sun, sunscreen should always be worn.
It is generally advised that the following groups of people take vitamin D supplements:
- Breastfed babies from birth to one year of age.
- Children ages 1-4 years old.
In the autumn, winter and early spring, children and adults may benefit from taking vitamin D supplements, especially those living in regions far from the equator.
Vitamin D supplements are typically available over-the-counter from pharmacies, but may also be prescribed by a doctor, who will be able to recommend the safest, most suitable supplement for a specific person.
Q: Can rickets occur in adults?
A: Yes, an equivalent of rickets can occur in adults, in a rare condition known as osteomalacia or soft bones. The two conditions share the same causes, symptoms and treatment options.
Q: How common is rickets?
A: Today, rickets is a rare condition in developed countries, in large part due to many common foodstuffs (such as cereals and bread) being fortified with vitamin D. However, children with darker skin, those who are not outside much and/or those without access to adequate nutrition are at risk of developing rickets, even in developed countries.
Nutrition Bulletin. “Vitamin D: An overview of vitamin D status and intake in Europe.” December, 2014. Accessed February 12, 2018. ↩