Vitamin D-deficiency rickets in adopted children from the former Soviet Union: an uncommon problem with unusual clinical and biochemical features

The Nutritional Status of Individuals Adopted Internationally as Children: A Systematic Review

Since 1955, international adoption has been a way of finding homes for children who have been orphaned or abandoned. We aimed to describe the nutritional status of individuals adopted internationally and their long-term nutritional and health outcomes. We searched four databases for articles published from January 1995 to June 2020, which included information on anthropometric or micronutrient status of children adopted internationally (CAI). Mean Z-scores on arrival to adoptive country ranged from -2.04 to -0.31 for weight for age; -0.94 to 0.39 for weight for height; -0.7 to 0 for body mass index; -1.89 to -0.03 for height for age; -1.43 to 0.80 for head circumference for age. Older children, those adopted from institutionalized care or with underlying disability, were more likely to be malnourished. Though long-term data was scarce, mean Z-scores post-adoption ranged from -0.59 to 0.53 for weight for age; -0.31 to 1.04 for weight for height; 0.39 to 1.04 for body mass index; -1.09 to 0.58 for height for age; -0.06 to 1.23 for head circumference for age. We conclude that though CAI are at high risk of malnutrition at baseline, marked catch-up growth is possible, including for those older than two years of age on arrival. This has implications not only for CAI but for the wider population of malnourished children worldwide. Research on how to optimize catch-up growth is a priority.

Auxological and endocrinological features in internationally adopted children

In internationally adopted children disorders of linear growth, puberty development, thyroid function, and bone metabolism are frequently reported. It is important that these children receive careful auxological and endocrinological evaluations and follow-up.Pediatricians and other healthcare providers should be aware that auxological and endocrinological problems are common in newly arrived international adoptees.

Vitamin D Status and Predictors of Hypovitaminosis D in Internationally Adopted Children

Objectives

To evaluate vitamin D status in internationally adopted children at first medical evaluation in Italy and to identify possible risk factors for hypovitaminosis D in this population.

Methods

25-hydroxyvitamin D [25(OH)D] levels were analyzed in internationally adopted children consecutively recruited at one Italian Center between 2010 and 2014 as part of the first screening protocol. Demographic, clinical and laboratory data were prospectively collected. Serum 25(OH)D levels <10 ng/mL, <20 ng/mL, and <30 ng/mL were used to define severe vitamin D deficiency, vitamin D deficiency and hypovitaminosis D, respectively.

Results

962 internationally adopted children (median age: 5.47 years; IQR:3.14–7.93) were included in the study. Median 25(OH)D level was 22.0 ng/mL (IQR:15.0–30.0 ng/mL); 710/962 (73.8%) children showed hypovitaminosis D (<30 ng/mL), 388/962 (40.3%) had vitamin D deficiency (<20 ng/dL), and 92/962 (9.6%) had severe vitamin D deficiency (<10ng/mL). No case of clinical rickets was observed. Hypovitaminosis D was particularly frequent (>90%) in children adopted from Ethiopia, Peru, India, Bulgaria and Lithuania. At multivariate analysis an increased risk of hypovitaminosis D was found to be associated with: age ≥ 6 years, time spent in Italy ≥ 3 months, blood sample taken in winter, spring or fall, compared to summer. Gender, ethnicity/continent of origin, tubercular infection, intestinal parassitosis and BMI-z-score < -2 were not associated with vitamin D status.

Conclusion

Hypovitaminosis D is common in internationally adopted children, from all ethnic group. The evaluation of serum 25(OH)D level could be useful early after the adoption to promptly start vitamin D supplementation/treatment if needed.

Severe lateral tibial bowing with short stature in two siblings--a provisionally novel syndrome

In this report, we describe two siblings with short stature and severe lateral tibial bowing. In the younger sibling, the bowing was bilateral, while in the older sib, it was unilateral. However, both showed bilateral abnormalities of the distal tibial epiphyses and growth plates. Pseudoarthrosis of the left distal tibial metaphysis and subsequent spontaneous resolution of the abnormality occurred in the younger sibling. The fibulas of both children were of normal diameter and were straight, except for the distal ends. Surgery has almost completely corrected the lower leg bowing in both patients. The type of tibial bowing seen in these children can be associated with a number of syndromes, such as neurofibromatosis type I, Weismann-Netter syndrome, and a variety of environmental caused disorders, such as vitamin D deficient rickets. However, the severity of the bowing present in our patients and the absence of other clinical features differentiates this condition from those reported in the literature. We posit that the condition in the children presented here represents an as yet undescribed syndrome, which is likely to be of genetic origin.

Nutritional rickets: still a problem for the pediatric population

Rickets is a mineralization disorder of the growing bone. Nutritional rickets is still prevalent in many parts of the developing world and is re-emerging in developed countries. Although vitamin D deficiency plays a central role in the pathogenesis of this disease, calcium deficiency and genetic factors may also cause or contribute to the development of rickets. This review will focus on the classical form of nutritional rickets, in other words, vitamin D-deficiency rickets. The epidemiology, ethiopathogenesis, risk factors, clinical picture, diagnosis, treatment and prevention of nutritional rickets are reviewed.

Inherited disorders of calcium homeostasis

In mammals a complicated homeostatic mechanism has evolved to maintain near consistency of extracellular calcium ion levels. The homeostatic mechanism involves several hormones, which comprise among others, parathyroid hormone and vitamin D. The recent resurge in vitamin D deficiency, as a global health issue, has increased interest in the hormone. In addition to vitamin D deficiency, other causes of rickets are calcium deficiency and inherited disorders of vitamin D and phosphorus metabolism. Vitamin D-resistant syndromes are caused by hereditary defects in metabolic activation of the hormone or by mutations in the vitamin D receptor, which binds the hormone with high affinity and regulates the expression of genes through zinc finger mediated DNA binding and protein-protein interaction. Current interest is to correlate the type/position of mutations that result in disorders of vitamin D metabolism or in vitamin D receptor function with the variable phenotypic features and clinical presentation. The calcium sensing receptor plays a key role in calcium homeostasis. Loss of function mutations in the calcium sensing receptor can cause familial benign hypocalciuric hypercalcemia in heterozygotes and neonatal severe hyperparathyroidism when homozygous mutations occur in the calcium sensing receptor. Gain of function mutation can cause the opposite effect causing autosomal dominant hypocalcemia. Mouse models using targeted gene disruption strategies have been valuable tools to study the effect of mutations on the calcium sensing receptor or in the vitamin D activation pathway. Dysfunctional calcium sensing receptors with function altering mutations may be responsive to treatment with allosteric modulators of the calcium sensing receptor. Vitamin D analogs which induce unusual structural conformations on the vitamin D receptor may have a variety of therapeutic indications. This review summarises recent advances in knowledge of the molecular pathology of inherited disorders of calcium homeostasis.

Shedding light on hypovitaminosis D and rickets

The recent resurgence of the ancient disease of vitamin D deficiency rickets and the widespread presence of hypovitaminosis D across the age spectrum pose significant challenges for today's clinicians. Furthermore, new research into previously unsuspected actions of vitamin D in multiple cell systems offer the possibility that vitamin D will play an increasingly important role in our understanding of a wide variety of disease states.

Nutritional rickets: nature or nurture?

Rickets is a mineralization disorder of the growing bone. Nutritional rickets is still prevalent in many parts of the world. Although vitamin D deficiency plays a central role in the pathogenesis of this disease, calcium deficiency and genetic factors may also cause or contribute to the development of rickets. This review will focus on the classical form of nutritional rickets: vitamin D deficiency rickets. Epidemiology, ethiopathogenesis, risk factors, the current clinical picture, diagnosis, treatment and prevention of nutritional rickets will be reviewed.

Acute care issues in internationally adopted children

Over the past decade there has been a dramatic increase in international adoptions in the United States. While most adopted children will have common illnesses, others may have unique medical issues as a result of the conditions in their birth country requiring a broadened differential diagnosis. Knowledge of these issues is essential in the management of these patients. This review will predominately focus on infectious disease issues commonly seen in international adoptees but will also discuss other medical conditions and some of the psychosocial issues which may be encountered by caregivers in the emergency department.

Updates in pediatric nutrition

Ongoing research in several areas of pediatric nutrition has new practical applications for community-based pediatricians. For example, a fresh understanding of risk factors for rickets persuades pediatricians to recognize and treat this disease, which was thought to be nearly extinct in the modern industrialized world. Similarly, an expanded awareness of the antibacterial components of breast milk encourages a more complete dialogue between pediatricians and new mothers about the potential benefits of breast-feeding. For those infants with feeding intolerance, new data help to refine the indications for hypoallergenic formulas, which are increasingly recommended for children with a variety of symptoms. The past year also has seen breakthroughs in our understanding of supplemental nutrition for children. Vitamin A may provide direct benefits for the most vulnerable of children, namely premature infants at high risk for lung disease. At the other end of the pediatric spectrum, adolescent athletes seeking to enhance their performance are consuming poorly studied sports supplements that may not be beneficial and may even be toxic. Finally, a greater appreciation for the epidemic of obesity that is sweeping the United States and other countries suggests that children at high risk may represent a far more diverse population than had been recognized previously.