Vitamin D & Rickets
There has recently been an increase in the number of case reports of rickets in the USA and other countries.[30,34–43] Inadequate intakes of either calcium or vitamin D or both can result in rickets. A recent analysis of 102 children with nutritional rickets in Denmark revealed two peaks in incidence, one at 0–4 years of age with a second peak during adolescence. Symptoms included pain in the legs in 62% of adolescents, refusal to support weight on legs in 33% of toddlers, skeletal pain in 29% of adolescents, epiphyseal swelling in 63% of toddlers, bowed legs in 52% of toddlers, rachitic rosary in 45% of toddlers and growth retardation in 39% of toddlers. Of the toddlers, 23% experienced generalized seizures that brought them to medical attention. Those with seizures had much lower calcium levels compared with those without seizures.
Robinson et al. retrospectively analyzed 126 cases of rickets from 1993–2003 in Sydney, Australia. The median age of presentation was 15.1 months, with 25% presenting at less than 6 months of age. The most common presenting features were hypocalcemic seizures (33%) and bowed legs (22%). Males comprised 64% of the cases, and presented at a younger age, with a lower weight standard deviation score, and more often with seizures. Most of the cases were from recently immigrated children or first-generation offspring of immigrant parents, with the region of origin the Indian subcontinent (37%), Africa (33%), the Middle East (11%) and Australia (79%). A total of 11 cases (all aged <7 months) presented atypically with hyperphosphatemia.
It is important to remember that nutritional rickets has effects outside of the bone and muscle. Recent case reports of cardiomyopathies associated with low 25(OH)D levels and rickets highlight the need to add vitamin D deficiency to the differential diagnosis of cardiac dysfunction.[45,46] In addition, as mentioned previously, although classically rickets mostly affects children aged 6–24 months and up to 5 years old, case reports of rickets with hypocalcemic seizures in adolescents are emerging.
Pediatr Health. 2010;4(1):89-97. © 2010 Future Medicine Ltd.
Cite this: Low Levels of 25-hydroxyvitamin D in the Pediatric Populations: Prevalence and Clinical Outcomes - Medscape - Feb 01, 2010.