It is a disease that compromises the normal mineralization of the growing skeleton. The bones become weak and soft, with possible pain in the legs and chest. There is often a delay in growth and a shorter stature than peers
When Rebecca’s pediatrician prescribed a simple vitamin D supplement “to prevent rickets,” her parents were perplexed. «Wasn’t rickets a disease of the past, almost disappeared?».
In reality, although today it is much less frequent than in the past, it can still appear in children, especially in the first years of life. Knowing it helps prevent it and intervene promptly when necessary.
What is rickets
To understand rickets, it is useful to start from the meaning of the word: it is a disease that compromises the normal mineralization of the growing skeleton. Children’s bones become softer, more deformable and more susceptible to injury. The underlying mechanism is almost always linked to vitamin D, an essential substance for the absorption of calcium and bone mineralisation. Without adequate levels of vitamin D, calcium and phosphorus cannot be properly incorporated into the bone.
From an epidemiological point of view, today rickets is rare in Western countries, but has not disappeared: it can occur in children with very selective diets, poor sun exposure, chronic pathologies or maternal deficiencies during pregnancy.
How to recognize rickets: symptoms in children
The most typical rickets symptoms depend on the degree of demineralization of the growing bone. The bones become weak and soft, with possible pain in the legs and chest. There is often a delay in growth and a shorter stature than peers.
Among the most characteristic signs are deformities of the lower limbs: bowed legs (varus), knees that “collapse” inwards (valgus) and difficulty in maintaining alignment while walking. At the level of the thorax, the so-called rachitic rosary (small swellings of the costal cartilages), pectus keel (deformity of the chest wall in which the sternum protrudes forward) and pectus excavatum (sinking of the central part of the sternum).
The skull may also be involved: in young children, craniotabes (softer occipital regions) and delayed closure of the fontanel may be observed. Wrists and ankles may appear thickened due to enlargement of the growth plates.
On the dental side, alterations of the enamel and a greater risk of tooth decay are possible. Many children also show hypotonia, delay in motor stages and, in the most advanced cases, bone fractures even with minimal trauma (so-called pathological fractures).
Causes of rickets
In rickets the main causes are almost always linked to a deficiency of vitamin D, calcium or phosphorus.
Role of vitamin D
Vitamin D is essential for skeletal health. It is produced by the skin thanks to sun exposure and to a lesser extent introduced through the diet. Once absorbed, it must be transformed by the liver and then activated by the kidneys, becoming calcitriol, its biologically active form. Calcitriol increases the absorption of calcium and phosphorus from the intestine and regulates bone remodeling. If one of these steps is missing, mineralization becomes insufficient.
Vitamin D and calcium deficiency
When vitamin D levels are low, the body cannot absorb enough calcium, resulting in hypocalcemia. The body reacts by increasing parathyroid hormone, which draws minerals from the bones to maintain calcium in the blood. This process causes demineralization, bone weakness and deformations. In many cases, hypophosphatemia is also present, which contributes to a picture of skeletal osteomalacia (defect in bone mineralization).
Risk factors for rickets
Some children are more likely to develop rickets. The first factor is poor sun exposure, which is fundamental for the production of vitamin D: it happens in children who spend little time outdoors or who have dark skin, because skin synthesis is less efficient.
Nutrition can also contribute: diets low in vitamin D and calcium, or prolonged exclusive breastfeeding without supplementation, may not guarantee a sufficient intake. Premature newborns and those born to mothers deficient in vitamin D also leave with reduced supplies. Finally, some medical conditions can hinder the absorption or activation of vitamin D, such as celiac disease, cystic fibrosis, or kidney and liver disease. Knowing who is most at risk helps to recognize the disease early and, above all, prevent it with simple daily habits.
Rickets in children: typologies
Childhood rickets. The most frequent type, generally due to vitamin D deficiency. It is typical of the first year of life and responds very well to therapy.
Malabsorption rickets. It appears in children with gastrointestinal diseases that prevent the absorption of vitamins or minerals, such as celiac disease or inflammatory bowel disease.
Other forms of rickets. Some rarer conditions include rickets from liver disease or from anticonvulsant drugs, which accelerate the breakdown of vitamin D.
How is rickets diagnosed?
The diagnosis of rickets in children arises first of all from clinical observation. The pediatrician evaluates the presence of the most typical signs – such as limb deformities, thickening of the wrists or growth retardation – and collects information on nutrition, sun exposure and any risk factors. When the suspicion is well-founded, blood tests are performed, which allow us to understand if bone mineralization is compromised: hypocalcemia, hypophosphatemia, increased alkaline phosphatase and sometimes elevated parathyroid hormone are often observed. The dosage of 25(OH)D is essential because it indicates the body’s vitamin D reserves.
Finally, x-rays show characteristic changes in the growing bones, useful both for confirming the picture and for assessing the severity of the disease. In particular situations, such as in suspected hereditary forms, genetic tests may be indicated. In many cases, however, the diagnosis already comes from the combination of examination, medical history and basic tests, without the need for more complex investigations.
Hypophosphatemic rickets is an inherited form in which the main problem is not vitamin D, but renal phosphate loss. The most common form is that linked to the X chromosome. These conditions are called vitamin D resistant rickets.
Alongside these are:
- vitamin D dependent rickets type 1 and 2 (defects in the activation or response to vitamin D);
- renal rickets due to tubulopathy;
- rare forms such as oncogenetic or fetal rickets.
How is rickets treated?
Treatment of rickets depends on the cause and degree of deficiency.
Treatment of deficiency rickets
It is the most common and easiest form to treat. It predicts:
- oral vitamin D supplementation;
- calcium supplementation when necessary;
- increased exposure to sunlight;
- improvement of eating habits.
In the past, the treatment of rickets with ultraviolet rays was also used, but is less common today thanks to the availability of safe and effective supplements.
Treatment of hypophosphatemic rickets
It involves combined therapy with oral phosphate and calcitriol. In recent years, burosumab, a monoclonal antibody that improves phosphate metabolism, has been available. Requires careful monitoring for possible side effects. More significant bone deformities may require orthopedic correction.
Prevention of rickets
The prevention of rickets comes above all from good daily habits, simple but very effective. Nutrition plays a central role: introducing complementary foods rich in vitamin D and calcium (such as milk, yogurt, fish and eggs) right from the start of the complementary diet helps to build healthy bones. In the first months of life, however, vitamin D supplementation is essential, recommended for all infants, especially those breastfed.
Sunlight is also an important ally. Short periods in the open air are enough, always with the necessary precautions, to promote the natural production of vitamin D by the skin. Finally, prevention begins already during pregnancy: an adequate intake of vitamin D in the expectant mother allows the newborn to be born with sufficient supplies, reducing the risk of deficiency in the first months of life.
Prognosis and expectations
The good news is that rickets, when recognized early and treated correctly, generally has an excellent prognosis. In most children, bone mineralization returns to normal and the deformities gradually resolve with growth.
The most delicate situations occur when the diagnosis arrives late or when there is a chronic disease underlying it: in these cases some deformities may persist and require longer follow-up.
Intervening early, however, allows you to avoid complications and guarantee the child adequate bone development.
