From the Guidelines
Rickets is a bone disorder caused by a deficiency of vitamin D, calcium, or phosphate, which are essential for proper bone formation, and its diagnosis should be based on signs of rickets and/or osteomalacia in association with hypophosphataemia and renal phosphate wasting in the absence of vitamin D or calcium deficiency, as recommended by the clinical practice guidelines for the diagnosis and management of x-linked hypophosphataemia 1.
Definition and Causes
Rickets is a condition that affects children during periods of growth, leading to soft, weak bones that can bend or break easily. It is caused by a deficiency of vitamin D, calcium, or phosphate, which are essential for proper bone formation. The condition can be inherited or acquired, and its severity varies widely, even among family members.
Symptoms and Diagnosis
Symptoms of rickets include bone pain, delayed growth, muscle weakness, and skeletal deformities such as bowed legs, thickened wrists and ankles, and a curved spine. The diagnosis of rickets should be considered in children with clinical and/or radiological signs of rickets, impaired growth velocity, and serum levels of phosphate below the age-related reference range associated with renal phosphate wasting and in the absence of vitamin D or calcium deficiency, as recommended by the clinical practice guidelines for the diagnosis and management of x-linked hypophosphataemia 1.
Treatment and Management
Treatment of rickets typically involves vitamin D supplementation, usually 2,000-4,000 IU daily for several months, along with calcium supplements (500-1,000 mg daily) if dietary intake is inadequate. Severe cases may require higher doses under medical supervision. Exposure to sunlight helps the body produce vitamin D naturally, so spending 15-30 minutes in sunlight a few times weekly is beneficial. Dietary changes to include vitamin D-rich foods (fatty fish, egg yolks, fortified milk) and calcium-rich foods (dairy products, leafy greens) are also important.
Biochemical Follow-up
Serum level of alkaline phosphatase (ALP) is a reliable biomarker of rickets activity and osteomalacia in children and adults, and should be measured regularly to evaluate the effectiveness of treatment 1. Parathyroid hormone (PTH) levels should also be measured regularly to monitor for secondary hyperparathyroidism, which can be promoted by oral phosphate supplementation.
Clinical Evaluation
Regular clinical evaluations are essential to monitor the progression of the disease and the effectiveness of treatment. This includes measurement of intercondylar and/or intermalleolar distance, height, and growth velocity, as well as assessment of limb deformity and joint alignment 1. Patients with substantial limb deformities should be evaluated by an orthopaedic surgeon with experience in metabolic bone disease.
From the Research
Definition and Characteristics of Rickets
- Rickets is a condition characterized by bone deformities due to defective bone mineralization and chondrocyte maturation in growing bones 2.
- It is typically caused by vitamin D and/or calcium deficiency 2, 3.
- Rickets can be classified into two major groups based on phosphate or calcium levels: phosphopenic and calcipenic 4.
Causes and Risk Factors
- Vitamin D deficiency is the most common cause of rickets 2, 4, 3.
- Calcium deficiency can also contribute to the development of rickets, especially in sunny countries where children have adequate vitamin D production from exposure to ultraviolet light 3, 5.
- Other risk factors include dark skin, exclusive breastfeeding, and limited access to dairy products or fortified foods 3.
Diagnosis and Treatment
- Rickets can be diagnosed based on history, physical examination, radiological features, and biochemical tests 4.
- Treatment typically involves vitamin D supplementation, with or without calcium, to achieve a serum 25-hydroxyvitamin D level of at least 20 ng/mL 2, 5.
- In some cases, calcium alone may be used to treat rickets, especially in children with adequate vitamin D levels but low dietary calcium intake 5.
Prevention
- Preventing nutritional rickets requires adequate intake of vitamin D through dietary sources, sunlight exposure, or supplementation 2, 3.
- The Endocrine Society recommends a serum 25-hydroxyvitamin D level of at least 30 ng/mL for maximum bone health in children and adults 2.
- Pregnant women and lactating mothers should take vitamin D supplements to ensure adequate levels for their infants 2.