Vitamin D and Rickets

Rickets is a medical condition in which children’s bones do not develop properly. It usually makes the bones weak and soft, eventually leading to deformities. It can also occur in adults, where it is called ‘osteomalacia’ or ‘soft bones’. The condition can cause significant pain in the bones, deformities of the skeleton, poor growth, curvature of the spine, bowed legs, and thickening of the knees, ankles and wrists. Children who suffer from rickets are at an increased chance of fracturing their bones.

The Cause of Rickets

Rickets is almost always caused by a deficiency in vitamin D and/or calcium. Vitamin D is a vital vitamin that our body produces by being exposed to the sun’s UVB rays. In addition, it is also found in a range of foods, sometimes naturally and sometimes because the food has been fortified. Natural sources include eggs and oily fish. It is vital that children, in particular, consume sufficient vitamin D so that they can grow healthy, strong bones.

There are some very rare cases in which a child is born with rickets due to the genes. Alternatively, the condition can develop because the body is not able to properly absorb vitamins and minerals. However, this is also very rare.

Who Gets Rickets?

In the past, rickets was a very common condition. However, towards the start of the 20th century, it started to disappear when the link between rickets and vitamin D was uncovered. At this point, cereals and margarine started to become fortified, which made a very big difference. Interestingly, however, rickets seems to be on the rise once again across the Western world. This is because people are once again suffering from low levels of vitamin D. Children who do not consume sufficient calcium and vitamin D are at risk of developing rickets. However, it is more common in those who have dark skin, because it is harder for them to absorb the UVB rays that are necessary for the synthesis of this vitamin. It can also occur in premature babies, as well as in those who take medication that stops the body from properly absorbing vitamin D.

The History of Rickets

The history of rickets is long and well-documented. First reports of its existence came from as long ago as 200 A.D. Medical journals from the 1640s also report that it was a common ailment, particularly in the United Kingdom. However, it wasn’t until the 1920s that the link between rickets and vitamin D was uncovered. It took another ten years for public health initiatives to start and to recommend that milk should be fortified with vitamin D and that children should take cod liver oil supplements. After the 1930s, rickets was virtually eradicated in industrialized nations, including our own.

Since the start of the 21st century, an increase in rickets has been noted. Interestingly, in the past, it was common among poorer, working class populations, where children often had to work and lived in high rise areas with virtually no sunshine. Now, however, it is more common in affluent population groups.

Interesting Facts About Rickets

• Rickets arises when a person has a phosphate, calcium or vitamin D deficiency. Phosphate and calcium are directly related to vitamin D, which means it is this deficiency in particular that lies at the heart of the condition.
• Different types of rickets exist, all of which are linked to the poor mineralization of phosphate and calcium, resulting from vitamin D deficiency.
• The skin synthesizes vitamin D if it is exposed to direct sunlight.
• Some foods contain vitamin D naturally.
• Mothers who exclusively breastfeed their children should take vitamin D supplements and give them to their children as well.

Different Types of Rickets

There are different types of rickets, as described in the table below.

Type Description
Nutritional rickets This is medically known as osteomalacia and is caused by a deficiency in vitamin D. Without vitamin D, the body cannot properly absorb phosphorous and calcium, which are essential for the formation of bones.

 

Children most at risk of nutritional rickets are:

·         Dark skinned children

·         Children who are exclusively breastfed

·         Children whose mother has a vitamin D deficiency

·         Children who do not spend any time in direct sunlight

·         Children following a vegan diet

Hypophasphatemic rickets This form or rickets is caused when the levels of phosphate in a patient’s blood are chronically low. As a result, bones become pliable and soft. This is due to a genetic mutation that stops the kidneys from properly controlling how much phosphate is excreted in urine. While the patient can absorb both calcium and phosphate, the phosphate is then fully lost. This form of rickets is not linked to a vitamin D deficiency. Symptoms tend to appear when the patient is one year old. Treatment involves calcitriol (vitamin D’s activated form) and phosphate supplements.
Renal (kidney) rickets This is comparable to hypophasphatemic rickets in as such that it is caused by disorders of the kidney. Here, however, too many electrolytes are lost in the urine, including phosphate and calcium. The symptoms are most comparable to severe nutritional rickets. Treatment involves nutritional supplementation and medical intervention on the kidneys.

Diagnosing Rickets

Initially, rickets is clinically diagnosed by looking at the full nutritional and medical history of the patients, including a complete physical examination. If a medical professional suspects that a child has rickets but does not suffer from any acute symptoms like tetany or seizures, x-rays of the long bones (femur, ulna and radius) and of the ribs are usually performed.

Medical professionals will measure vitamin D levels, the parathyroid hormone (which is involved in controlling phosphate and calcium), alkaline phosphatase and electrolytes. They will also run kidney function measurement tests, for creatinine and blood urea nitrogen (BUN). These are done particularly if any of the following characteristics, consistent with rickets, are found on the x-rays.

• Abnormally shaped or widening metaphysis, which is when the quickest growing part of the bone scores below the regular growth plate.
• If the femurs are obviously bowing.
• If osteopenia is noted, which is when the bones show signs of decreased mineralization, most particularly lack of density.
• Rachitic rosary, which is when the ribs flare.
• If there are multiple fractures that are in the process of healing.

Because there are different causes of rickets, it is important that laboratory tests are completed. However, vitamin D deficiency is usually the underlying issue. This is shown by a decrease in vitamin D and an increase in the parathyroid hormone, as well as a decrease in phosphate and calcium.

Rickets Treatment

Luckily, most children who suffer from rickets can be treated. They must change their diet so that the consume enough vitamin D and calcium. This is generally achieved through vitamin supplements. If, however, the children also suffer from a medical problem that prevents them from properly absorbing supplements, they may need to take an increased dosage. Some children also need a yearly injection of vitamin D.

Rickets Prevention

Rickets is a fully preventable illness. So long as the diet contains sufficient vitamin D and calcium, and so long as people spend at least some time in the sunshine, they should not suffer from it. The only sun exposure that is needed is about 15 minutes of sunlight on your face and hands, four times a week during the spring and the summer. If this is impossible, or if you fall in a category where you are more likely to develop rickets, then supplementation will help to prevent the condition.

Prognosis

Luckily, the prognosis for children who are diagnosed as having nutritional rickets is excellent. The earlier the diagnosis, the better the outcome will be. If their diet is properly supplemented with vitamin D and calcium, their bone defects can be healed within just a few days. Even severe bowing, which happens when people have had rickets for a longer period of time, can be fully resolved without surgery, although it may take a few years. In very rare and advanced cases, the bone changes may be permanent, however.

Hope for Rickets – Vitamin D, the Sunshine Vitamin

Medical professionals are responsible for making sure their patients are educated on how to prevent rickets. Expectant mothers are told to take prenatal vitamins and their nutritional habits should also be examined. New mothers have to be told about vitamin D supplementation, particularly if they exclusively breastfeed. Additionally, once the child starts to wean, nutritional counselling should be offered in order to prevent rickets, as well as explaining to parents that sun exposure is very important, in the right quantities.

All over this country, medical professionals are starting to gain an understanding of the fact that children are once again suffering from vitamin D deficiency. Some 30% of children in this country now have at least some deficiency, but the percentage is much higher globally. The American Academy of Pediatrics released a paper in 2011 that concluded children should receive vitamin D supplementation while avoiding direct sunlight exposure due to the risk of cancer. Further studies are taking place in how much vitamin D a person should receive, although the current recommended value is 400 IU per day. It is important for further research to take place, not in the least because not everybody is able to have access to vitamin D supplementation.

Resources and References:

Vitamin D and Rickets – Relationship between rickets and vitamin D. (Vitamin D Council)
Overview of Rickets – General information on rickets. (Mayo Clinic)
UV Radiation: A Hazard to Children and Adolescents – Effects of UV radiation on children and adolescents. (American Academy of Pediatrics)