Rickets is a childhood bone condition wherein the bones soften and become prone to fractures and irregularities. The main cause of rickets is a lack of vitamin D, but people can also inherit a certain type of rickets.
As a result, developing bones can become weak and may form irregularly. People may also experience bone pain. The resulting symptoms can persist into adulthood. A severe vitamin D deficiency in adulthood can lead to osteomalacia, which is similar to rickets.
A vitamin D deficiency may result from a low dietary intake of vitamin D or low exposure to or absorption of ultraviolet (UV) rays. This means that children who spend a lot of time indoors may be at risk of vitamin D deficiency and rickets.
Rickets can also result from some metabolic and genetic conditions.
Taking vitamin D supplements may help protect those at risk.
This article will outline the symptoms, causes, and treatments associated with rickets, as well as how best to prevent it.
Some signs and symptoms of rickets may include the following:
- bone pain or tenderness
- bones that grow slowly
- bowed or curved legs
- muscle weakness
- bones that are soft and break easily
- a large forehead or abdomen
- an unusual shape to the ribs and breastbone
- wide joints in the elbows and wrists
- dental cavities and irregularities
In the short-term, severely low calcium levels in the blood can lead to cramps, seizures, and breathing problems.
In severe cases, untreated, long-term nutritional rickets can increase the risk of:
- bones that break easily
- permanent bone irregularities
- heart problems
- obstructed labor
- lifelong disability
There are several causes of rickets, including:
Lack of vitamin D
The human body needs vitamin D to absorb calcium from the intestines. UV rays from sunlight help the skin cells convert a precursor of vitamin D from an inactive to an active state.
If a person does not make or consume enough vitamin D, their body may not absorb sufficient calcium from the food they eat, causing low levels of calcium in the blood.
Low calcium levels result in irregularities of the bones and teeth, as well as nerve and muscle problems.
Children may lack vitamin D if they:
- have dark skin
- spend a lot of time indoors
- always wear sunscreen when outside
- follow a lactose-free or strict plant-based diet
- have a health condition such as celiac disease, which prevents the body from making or using vitamin D
- live in a place with high levels of air pollution
Regarding infants, the Centers for Disease Control and Prevention (CDC) note that breast milk does not provide enough vitamin D. According to the CDC, the American Academy of Pediatrics recommend vitamin D supplements of 400 international units (IU) (10 micrograms [mcg]) for infants who are wholly or partially breastfed. Formula milk tends to be fortified with vitamin D.
Learn more about vitamin D here.
Some types of rickets result from a genetic condition. These may be hereditary.
Hypophosphatemic rickets, for example, is a rare condition in which the kidneys are unable to process phosphate properly. Low levels of phosphate in the blood lead to weak and soft bones.
The most common type affects around 1 in 20,000 newborns.
Genetic factors that affect the body’s ability to use calcium can result in rickets, including those that affect liver, kidney, and intestinal function.
Calcium is also important for bone strength. Find out which foods provide calcium here.
Factors that can increase the risk of rickets include:
- a low dietary intake of vitamin D
- a lack of opportunity to spend time outdoors
- not taking vitamin D supplements despite a high risk of developing rickets
One 2015 study found that Alaska Native children had a higher risk of rickets due to poor nutrition, a lack of vitamin D supplementation, and latitude (very little UV light reaches the earth from November to February in this region).
Get some tips on how to strengthen the bones naturally here.
Treatment will aim to maximize the individual’s intake of calcium, phosphate, and vitamin D.
Depending on the underlying cause, a doctor will usually prescribe vitamin D supplements.
They may also recommend:
- increasing exposure to sunlight
- making dietary changes
- taking fish oil
- getting more exposure to UVB light
- consuming calcium and phosphorus
Get more information on vitamin D and joint pain here.
If rickets results from a poor diet, a doctor may prescribe:
- daily calcium and vitamin D supplements
- an annual vitamin D injection (if a person cannot take supplements orally)
- a diet plan that focuses on foods rich in vitamin D
To add vitamin D to the diet, a person can consume:
- cod liver oil
- oily fish, such as salmon, tuna, sardines, and swordfish
- vitamin D-fortified foods, such as milk, some juices, many cereals, some brands of margarine, and some soy milk products
- beef liver
Making dietary changes and spending some time outside each day can help prevent rickets in most children.
Treating medical causes
If the cause is genetic, a doctor may prescribe phosphate and calcitriol supplements to reduce bowing in the legs.
If there is an underlying medical cause, such as kidney disease, treating it may help prevent rickets.
A doctor will diagnose rickets by checking for symptoms such as bowed legs or a soft skull. They may also ask about a person’s lifestyle habits, such as diet and sun exposure.
To confirm a diagnosis, a doctor may recommend:
Blood tests: These look for low levels of calcium and phosphorus and high levels of alkaline phosphatase.
An arterial blood gas test: This checks for acidity in the blood.
X-rays: These may reveal calcium loss in bones or alterations in the structure or shape of the bones.
A bone biopsy: This can confirm rickets, but doctors rarely use it.
In this article, learn about osteoporosis, a condition that can affect older people.
In most cases, people can prevent rickets by consuming enough vitamin D and getting enough sun exposure.
How much vitamin D?
The Office of Dietary Supplements (ODS) recommend a daily intake of:
- 400 IU (10 mcg) for infants aged 0–12 months
- 600 IU (15 mcg) for people aged 1–70 years
- 800 IU (20 mcg) for those above 70
However, it is difficult to say exactly how much vitamin D each individual needs, as it depends on how much sun exposure they have and how much vitamin D their body is able to synthesize in the skin as a result of this.
Children who live in countries with low sun intensity, where there is frequent cloud cover, or where winter days are particularly short may need to take vitamin D supplements to prevent rickets.
This may involve:
- consuming fortified milk, orange juice, and other products rich in vitamin D
- taking a daily vitamin D supplement
- taking an occasional high dose of vitamin D when small daily doses are not possible
Rickets can develop if a child has too little vitamin D. It is rare in the U.S., but some people have a higher risk of developing it due to skin color, a lack of time spent out of doors, or a poor diet.
Anyone who has concerns that their child may have a vitamin deficiency should speak with a doctor. They can advise on supplements and sun exposure.
People should always speak to their doctor before using supplements, as they can interact with other medications. In addition, obtaining too much vitamin D may not be healthful, according to the ODS.
How can a person get more vitamin D from the sun? Learn more here.
I am confused about letting my children stay in the sun. How long should they stay out to get enough vitamin D without increasing the risk of skin cancer?
All children should have protection from the sun to prevent sunburn and decrease the risk of skin cancer, particularly melanoma. Means of protection include frequent application of sunscreen and wearing protective clothing, so that they can spend plenty of time outside.
However, sunscreen limits the skin’s ability to make vitamin D, so it is not possible to safely get all the vitamin D we need just by spending time outdoors. Eating and drinking vitamin D-fortified foods and milk is the best option.
Parents and caregivers can ask their child’s doctor about supplements if they do not think that they are getting enough vitamin D from their diet.
Karen Gill, M.D. Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.