Approach Considerations
Treatment for rickets may be administered gradually over several months or in a single-day dose of 15,000 mcg (600,000 U) of vitamin D. [7] If the gradual method is chosen, 125-250 mcg (5000-10,000 U) is given daily for 2-3 months until healing is well established and the alkaline phosphatase concentration is approaching the reference range. Because this method requires daily treatment, success depends on compliance.
If the vitamin D dose is administered in a single day, it is usually divided into 4 or 6 oral doses. An intramuscular injection is also available. Vitamin D (cholecalciferol) is well stored in the body and is gradually released over many weeks. Because both calcitriol and calcidiol have short half-lives, these agents are unsuitable for treatment, and they bypass the natural physiologic controls of vitamin D synthesis.
The single-day therapy avoids problems with compliance and may be helpful in differentiating nutritional rickets from familial hypophosphatemia rickets (FHR). In nutritional rickets, the phosphorus level rises in 96 hours and radiographic healing is visible in 6-7 days. Neither happens with FHR.
A study by Dabas et al compared the efficacy of daily versus weekly oral vitamin D3 therapy in the radiologic healing of nutritional rickets. Children who received daily supplementation had greater increases in their radiologic scores from baseline than those who received weekly therapy. [8]
A study by Thacher et al sought to determine the optimal dose of calcium for treatment of children with rickets. The authors reported that a daily calcium intake of 1000 mg or 2000 mg resulted in more rapid radiographic healing than 500 mg per day dosing. However no clinical or radiographic differences were found between daily calcium supplements of 2000 mg and 1000 mg. The study also found that complete healing of nutritional rickets may take some children longer than 24 weeks. [9]
If severe deformities have occurred, orthopedic correction may be required after healing. Most of the deformities correct with growth.
A consultation with a pediatric endocrinologist is recommended.
Deterrence/Prevention
Human milk contains little vitamin D and contains too little phosphorus for babies who weigh less than 1500 g. Infants weighing less than 1500 g need special supplementation (ie, vitamin D, calcium, phosphorus) if breast milk is their primary dietary source. Recommending a vitamin D supplement from the first week of life for susceptible infants who are breastfed is safe and effective and, therefore, should be considered. [10]
The United States Institute of Medicine recommends an upper level of intake of 1000 IU/d and 1500 IU/d in infants aged 0-6 months and 6-12 months, respectively. An adequate intake of 400 IU/d has been suggested for infants aged 0-12 months. The recommended daily allowance is 600 IU/d thereafter. [11] The US Endocrine Society’s Clinical Practice Guideline suggests 400-1000 IU/d may be needed for children younger than 1 year; they also recommend 600-1000 IU/d for children aged 1 year or older. [12] Internationally, the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition also suggests an oral supplement of 400 IU/d until age 1 year. [13]
Adequate ultraviolet light or 10 mcg (400 IU) orally (PO) daily of a vitamin D preparation and an adequate dietary supply of calcium and phosphorus prevent rickets. [14, 15] As little as 20 min/d of ultraviolet light to the face of a light-skinned baby is sufficient; however, significantly longer periods of exposure are necessary for children with increased skin pigmentation.
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Findings in patients with rickets.
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Anteroposterior and lateral radiographs of the wrist of an 8-year-old boy with rickets demonstrates cupping and fraying of the metaphyseal region.
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Radiographs of the knee of a 3.6-year-old girl with hypophosphatemia depict severe fraying of the metaphysis.
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Radiograph in a 4-year-old girl with rickets depicts bowing of the legs caused by loading.
