Cord blood vitamin D levels of term neonates

We estimated cord blood 25-hydroxy vitamin D levels of 50 term healthy neonates born in a tertiary care center of Kozhikode, Kerala, India. Vitamin D levels were normally distributed with a mean (SD) value of 11.36 (4.75) ng/mL and median (range) values of 10.85 (3.9-24.9) ng/mL. Majority of babies had values between 5 to 15 ng/mL. This study shows that even in tropical climates most of our neonates are born with deficient vitamin D levels.

Vitamin D and skeletal health in infancy and childhood

During growth, severe vitamin D deficiency in childhood can result in symptomatic hypocalcaemia and rickets. Despite the suggestion from some studies of a secular increase in the incidence of rickets, this observation may be driven more by changes in population demographics than a true alteration to age, sex and ethnicity-specific incidence rates; indeed, rickets remains uncommon overall and is rarely seen in fair-skinned children. Additionally, the impact of less severe vitamin D deficiency and insufficiency has received much interest in recent years, and in this review, we consider the evidence relating vitamin D status to fracture risk and bone mineral density (BMD) in childhood and adolescence. We conclude that there is insufficient evidence to support the suggestion that low serum 25-hydroxyvitamin D [25(OH)D] increases childhood fracture risk. Overall, the relationship between 25(OH)D and BMD is inconsistent across studies and across skeletal sites within the same study; however, there is evidence to suggest that vitamin D supplementation in children with the lowest levels of 25(OH)D might improve BMD. High-quality randomised trials are now required to confirm this benefit.

[Osteoporosis]

The quality of the management of patients with osteoporosis varies by country. The recommendations of the Swiss Association against osteoporosis propose intervention thresholds based on the results of the FRAX tool. Despite increasing number of observational studies with several hundred thousands of patients, it is not possible to conclude to a clear increased risk of cardiovascular disease with calcium intakes. A persistent effect of zoledronic acid is observed even after one single injection. There is no increased fracture risk within 7 months following Denosumab treatment cessation.

Nutritional rickets around the world

Nutritional rickets is a major public health problem in many countries of the world. The disease is characterized by deformities of the long bones, enlargement of the wrists and costochondral junctions, hypotonia and, in infants, craniotabes and delayed fontanelle closure. Predominantly caused by severe vitamin D deficiency, rickets can also be associated with hypocalcemic seizures and cardiac failure. First presentation is typically at 6-24 months of age, although hypocalcemia may be evident in younger infants. In many affluent industrialized countries, the prevalence of rickets in the general population diminished after the introduction of clean-air legislation and dietary supplementation. However, in such countries, vitamin-D deficiency rickets has re-emerged in recent years, particularly among groups with limited exposure to UVB-containing sunshine. Infants at risk of rickets tend to be those whose mothers had poor vitamin D status during pregnancy and those exclusively breast-fed for a prolonged period with little skin exposure to UVB. In other countries of the world, the prevalence of rickets can be high, even in regions with abundant year-round UVB-containing sunshine. In general, this is also due to vitamin D deficiency related to limited sun exposure. However, reports from Africa and Asia suggest that there may be other etiological factors involved. Studies in South Africa, Nigeria, The Gambia and Bangladesh have identified rickets in children, typically 3-5 years old at first presentation, in whom plasma 25-hydroxyvitamin D concentrations are higher than those characteristic of primary vitamin D deficiency. Calcium deficiency has been implicated, and in some, but not all, disturbances of phosphate metabolism, renal compromise and iron deficiency may also be involved. Continuing studies of the etiology of nutritional rickets will provide evidence to underpin guidelines for the prevention and treatment of rickets world-wide. This article is part of a Special Issue entitled 'Vitamin D Workshop'.

Prevalence of classic signs and symptoms of rickets and vitamin D deficiency in Mongolian children and women

In order to assess the current nutrition status of Mongolian population, including rickets and vitamin D deficiency of children and women, the Fourth National Nutrition Cross-Sectional Survey was conducted in 21 aimags (provinces) of 4 economic regions of the country and capital city Ulaanbaatar in 2010. Children of age under five years, and non-pregnant women of reproductive age were used as subjects for assessing rickets and vitamin D deficiency. A total of 400 households were randomly selected from each of 4 economic regions and Ulaanbaatar city. Clinical examinations were performed on 706 children of age under five years. Interviews were used to assess vitamin D supplement use. The serum level of 25-hydroxyvitamin D was measured in 524 children aged 6-59 months and in 867 women of reproductive age. This survey found that 21.8% of children had vitamin D deficiency, 20.6% had low vitamin D reserve, and 30.0% of women had vitamin D deficiency and 22.2% had low vitamin D reserve. The prevalence of vitamin D deficiency in children (35.0%, 95% CI, 24.7-47.0) and women (54.9%, 95% CI 45.5-64.0) in the Eastern Region was (35.0%, 95% CI, 24.7-47.0) significantly higher than in the Western, Khangai, Central Regions, and Ulaanbaatar. Further it was found that 27.4% of children under-two years had received vitamin D supplementation. The proportion of children, who did not receive vitamin D supplementation had a higher prevalence of vitamin D deficiency than that of the children of the Eastern Region. None of the women who were involved in this survey had received vitamin D supplementation; 10.2% of them had delivered in the past 12 months, and 22.5% were breastfeeding. The prevalence of classic signs and symptoms of rickets were commonly reported among children of age under five, and skeletal abnormalities more commonly reported in children aged 12-47 months. In conclusion, there is a high prevalence of classic signs and symptoms of rickets in children of age under five years. Vitamin D supplementation in adequate doses for the prevention and treatment of rickets in children is insufficient. Thus, a trial survey is needed to assess the safe and effective doses of vitamin D supplementation necessary for the maintenance of normal serum 25-hydroxyvitamin D concentrations in Mongolian children, and women. In addition, a vitamin D food fortification program is required. This article is part of a Special Issue entitled 'Vitamin D Workshop'.

Increasing incidence of nutritional rickets: a population-based study in Olmsted County, Minnesota

OBJECTIVE

To determine temporal trends in incidence and risk factors of nutritional rickets in a community-based population.

PATIENTS AND METHODS

Rochester Epidemiology Project data were used to identify all children (aged <18 years) residing in Olmsted County, Minnesota, between January 1, 1970, and December 31, 2009, with diagnostic codes corresponding to rickets, vitamin D deficiency, hypovitaminosis D, rachitis, osteomalacia, genu varum, genu valgum, craniotabes, hypocalcemia, hypocalcemic seizure, and tetany. Record abstraction was performed to select individuals with radiographic confirmation of rickets. Age- and sex-matched controls were identified for the evaluation of risk factors. The main outcome measure was radiographic evidence of rickets without identifiable inherited, genetic, or nonnutritional causes. Incidence rates were calculated using Rochester Epidemiology Project census data.

RESULTS

Of 768 children with eligible diagnostic codes, 23 had radiographic evidence of rickets; of these, 17 children had nutritional rickets. All 17 children were younger than 3 years, and 13 (76%) were of nonwhite race/ethnicity. Clinical presentation included poor growth (n=12), leg deformity (n=8), motor delay (n=5), leg pain (n=3), weakness (n=3), and hypocalcemia or tetany (n=2). The incidence of nutritional rickets in children younger than 3 years was 0, 2.2, 3.7, and 24.1 per 100,000 for the decades beginning in 1970, 1980, 1990, and 2000, respectively (P=.003 for incidence trend). Nutritional rickets was associated with black race, breast-feeding, low birth weight, and stunted growth (P<.05 for all). Four of 13 patients (31%) who underwent 25-hydroxyvitamin D testing had values less than 10 ng/mL.

CONCLUSION

Nutritional rickets remains rare, but its incidence has dramatically increased since 2000. Not all cases of rickets can be attributed to vitamin D deficiency.

High incidence of rickets in extremely low birth weight infants with severe parenteral nutrition-associated cholestasis and bronchopulmonary dysplasia

Risk factors for rickets of prematurity have not been re-examined since introduction of high mineral formula, particularly in ELBW infants. We analyzed the incidence and the risk factors of rickets in extremely low birth weight (ELBW) infants. As a retrospective case-control study from 2004 to 2008, risk factors were analyzed in 24 patients with rickets versus 31 patients without. The frequency of rickets in ELBW infants was 24/55 (44%). Infants with rickets were diagnosed at 48.2 ± 16.1 days of age, and improved by 85.3 ± 25.3 days. By radiologic evaluation, 29% were grade 1 rickets, 58% grade 2 and 13% grade 3. In univariate analysis, infants with rickets had significantly higher incidence of patent ductus arteriosus, parenteral nutrition associated cholestasis (PNAC), severe PNAC and moderate/severe bronchopulmonary dysplasia (BPD). In multiple regression analysis, after adjustment for gestation and birth weight, rickets significantly correlated with severe PNAC and with moderate/severe BPD. Serum peak alkaline phosphatase levels were significantly elevated in rickets (P < 0.001). In ELBW infants, the incidence of rickets of prematurity remains high and the incidence of severe PNAC and moderate/severe BPD was significantly increased 18 and 3 times, respectively.

Spatial distribution of calcium in food, water and soil and its possible influence on rickets disease in Northern Nigeria

Since the 1990s, children of the Gbagyi tribe in Northern Nigeria have been suffering severe rickets with an incidence of up to 40% in the children's generation. The disease seems to be prevalent in an area of approximately 100 km(2) south-east of Kaduna. According to broad medical studies in that area, there is no evidence for a genetic disposition but for a nutritional cause of the disease. A lack of calcium was found in blood and was calculated to originate from diet. We therefore checked parent material, soil, maize cobs (Zea mays) and drinking water for their specific Ca contents from a region with rickets problem (study area A) and compared the results to Ca amounts in similar samples from a region where rickets is unknown among the Gbagyi population (study area B). It thereby became apparent that there are no differences in mineralogical composition of the parent material between the study areas, but that Ca contents in soil, maize cobs and drinking water are 47.6%, 26.6%, respectively, 79.1% lower in study area A compared to study area B. This result suggests that there may indeed be a nutritionally and/or environmentally influence on rickets disease. Nevertheless, further research on this topic is required.

Iron status and fibroblast growth factor-23 in Gambian children

A relationship between iron and fibroblast growth factor-23 (FGF23) metabolic pathways has been proposed. Iron deficiency anaemia is prevalent in The Gambia and concentrations of fibroblast growth factor-23 FGF23 are elevated in a large percentage of Gambian children with rickets-like bone deformity. We speculate that low iron status may be involved in the aetiology of Gambian rickets. The aim of this study was to determine if there was a relationship between haemoglobin, as a marker of iron status, and FGF23 in samples from children with and without a history of rickets-like bone deformities in The Gambia. We conducted a retrospective analysis of studies carried out from 2006 to 2008 in children from a rural community in The Gambia where iron deficiency anaemia is endemic and where elevated circulating concentrations of FGF23 have been found. To investigate the relationship between circulating FGF23 and haemoglobin concentrations we used an age-adjusted linear regression model on data from children <18y of age with a family or personal history of rickets-like bone deformity (BD) (n=108) and from the local community (LC) (n=382). We found that circulating concentration of FGF23 was inversely correlated with haemoglobin concentration. This effect was more pronounced in BD children compared with LC children (interaction: P≤0.0001). Anaemia and elevated FGF23 were more prevalent in BD children compared to LC children (P=0.0003 and P=0.0001 respectively). In conclusion, there is a stronger relationship between FGF23 and haemoglobin in Gambian children with a history of rickets compared to local community children. This study provides support for the contention that iron may be involved in FGF23 metabolic pathways.

Time to see the light

There is growing concern about low vitamin D levels in the UK population, and children from a range of backgrounds are now presenting with rickets, the bone disease associated with poor nutrition in the 19th century. However, the evidence linking vitamin D deficiency to a range of conditions unconnected to bone health, such as heart disease and multiple sclerosis, is inconclusive.

Rickets in Denmark

Rickets is a heterogeneous group of diseases of the growing child caused by defect mineralization of bone. Nutritional rickets is caused by deficiency of vitamin D, calcium or both. Several hereditary forms of rickets exist where the disease proceeds into adulthood. Nutritional rickets was common in the past, but by introduction of preventative administration of cod liver oil and vitamin D supplementation, nutritional rickets became a rarity. During the last decades, case reports of nutritional rickets reappear in the industrialized countries. It is the general conception that in the industrialized countries, hereditary rickets is the most prevalent cause of rickets today. However, the incidence of nutritional rickets and the incidence and prevalence of hereditary rickets in Scandinavia are unknown. The most common form of hereditary rickets is hypophosphatemic rickets (HR). The geno- and phenotype among Scandinavian patients have not been characterized. Especially, the disease in adult patients is not well described. Moreover, there are conflicting reports of the benefits of medical treatment throughout childhood, and in addition on gender differences in disease severity.

Prevalence of vitamin D deficiency and rickets in children with cholestasis in Iran

This study was aimed to determine prevalence of vitamin D deficiency and rickets in children with cholestatic liver diseases. Forty eight children with established cholestatic liver disease who referred to gastrointestinal clinic of Children Medical Center (Tehran, Iran) between April 2010 and March 2011 were enrolled in a cross-sectional study. Laboratory analysis including calcium, phosphate, albumin, total and direct bilirubin, aminotransferases, alkalinephosphatase (ALP), prothrombin time (PT), parathyroid hormone (PTH), total protein determined by routine laboratory techniques. Mean age of participants was 299.1 ± 676.8 days (range 2-3600 days) whereas twenty one were female (43.8%) and 27 (56.3%) were male. Twenty two (45.8%) had evidences of rickets in X-ray evaluation. Three children with rickets and two with normal X-ray had vitamin D deficiency while ten in rickets group and 16 in normal group had vitamin D insufficiency. The main underlying diseases were anatomical biliary atresia in cases with rickets and idiopathic in other group. Rickets and vitamin D deficiency should be considered in chronic cholestatic children.

Vitamin D deficiency and prevention: Turkish experience

A nationwide 'vitamin D prophylaxis augmentation programme' initiated in 2005 in Turkey reduced the prevalence of rickets from 6% in 1998 to 0.1% in 2008 in children under 3 years of age. The programme included free distribution of vitamin D drops to all newborns and infants (0-12 months) visiting primary health stations throughout the country. Free disposal of vitamin D to infants is an effective strategy for preventing vitamin D-deficient rickets.

Rickets: concerns over the worldwide increase

Rickets is a childhood disease that causes a softening of the bones, potentially leading to fractures and deformity. Eighty years ago it was thought to have largely been eradicated from the U.K. However a recent increase in cases of rickets, not just in Britain but around the world, has proven this isn't the case. Today the disease affects children from all types of socio-economic backgrounds, not just the poorer ones, and it is primarily caused by low levels of vitamin D and certain foods. In January 2011 the government's chief medical officer Dame Sally Davies recommended all children aged six months to five should be given vitamin D supplements, particularly during winter months when natural sunshine is limited. The irony is that the advice in recent years for children to wear a high factor sunscreen and remain covered up while playing outdoors are partly felt to be behind the reason for its re-emergence. Parents and health professionals alike were shocked when it was revealed that a school girl living on the Isle of Wight developed rickets precisely because of her mother's vigilance at following sun safety rules. NICE, in their latest report (Jan 2011) stated that: "Exposure to the sun has a number of benefits. For example, it increases people's sense of wellbeing, allows them to synthesise vitamin D and provides opportunities for physical activity". A tendency for children to stay indoors and watch TV or play on computer games, rather than play outside when the sun is shining, is arguably also another contributing factor.

An outbreak of rickets in Corriedale sheep: Evidence for a genetic aetiology

CASE HISTORY

A skeletal disease characterised by lameness, limb deformities and reduced growth rate occurred over two successive years in lambs born on a commercial sheep farm in Marlborough. A genetic aetiology was considered likely following exclusion of other known causes of rickets and because of the progressive nature of the disease, even after affected animals were transferred to another property.

CLINICAL FINDINGS

Affected lambs appeared normal at birth but developed clinical signs during the first 2 months of life. The most severely affected animals either died or were euthanised within the first year of life, but some survived to breeding age. Serum biochemistry revealed hypocalcaemia, hypophosphataemia and increased concentrations of 1,25 dihydroxyvitamin D. The mean serum 25 hydroxyvitamin D concentration was similar to that of control lambs.

PATHOLOGICAL FINDINGS

Gross lesions included enlarged costochondral junctions, bilateral irregularity of articular surfaces on humeral heads due to collapse of subchondral bone, thickened cortices in long bones and irregular thickening of physeal cartilages. Microscopically, tongues of hypertrophic chondrocytes extended from physes into metaphyseal regions; metaphyseal trabeculae were thick, disorganised and often lined by wide osteoid seams. Osteoclastic activity was excessive both in cortical and trabecular bone.

DIAGNOSIS

Inherited rickets in Corriedale sheep. CLINICAL RELEVANCE AND CONCLUSIONS: This disease is likely to be present in several Corriedale sheep flocks in New Zealand and may have been misdiagnosed as arthritis or other diseases causing lameness and/or poor growth. A defect in end-organ responsiveness to 1,25 dihydroxyvitamin D is the likely mechanism. This disease of sheep may be a useful model for studying vitamin D metabolism and the treatment of inherited forms of rickets in human beings.

Proceedings of the Rank Forum on Vitamin D

The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations>75 nmol/l). Any discussion of 'optimal' concentration of serum 25(OH)D needs to define 'optimal' with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations.

Evaluation of children with nutritional rickets

AIM

To evaluate the clinical findings, risk factors, therapy and outcome in 946 children with nutritional rickets.

PATIENTS AND METHODS

This retrospective study included a review of medical records of patients with nutritional rickets between March 2004 and 2009. Patients who displayed both the biochemical inclusion criteria and the clinical signs/symptoms or radiological signs of rickets were included in the study.

RESULTS

The present study included 946 patients aged between 4 months and 15 years. Distribution of the cases showed a density between December and May. The age at diagnosis, showed two peaks and most of the patients were in the age range 0-23 months and 12.0-15 years. In infants and young children, most of the patients had been admitted to the hospital due to infectious diseases. In older children, short stature and obesity were the most common complaints.

CONCLUSION

Children aged between 0-23 months and 12.0-15 years were under most risk for nutritional rickets, especially in winter and spring and vitamin D should be given to them as supplementation dose.

Frequency of nutritional rickets in children admitted with severe pneumonia

OBJECTIVE

To determine the frequency of nutritional rickets in children hospitalized with severe pneumonia.

METHOD

This study was carried out at the department of paediatric medicine at National Institute of Child Health Karachi. It is a case series done over a period of six months from 15th November 2008 to 15th may 2009. Patients admitted (n=137) with severe pneumonia were included in the study and were investigated for presence of rickets with serum calcium, phosphorus and alkaline phosphatase. Those having low to normal calcium low phosphorus and raised alkaline phosphatase were labeled as having rickets. All data collected were entered on Performa. Children with familial, vitamin D dependent/resistant rickets, secondary rickets, and cerebral palsy or on anti convulsant therapy were excluded from this study.

RESULTS

Out of 137 patients, with severe pneumonia, 83 were male and 54 female. Frequency of nutritional rickets in children with severe pneumonia was observed in 101(74%) cases. Rickets was more common in 2 to 12 months of age, i.e., 79.8% (67/84) and in those children who were breast fed (85.3% vs. 40%). Frequency was higher in those children who were not exposed to sunlight.

CONCLUSION

Pneumonia is a very common presentation of rickets. This study suggests that rickets may be more common in children who are breast fed and those who have less exposure to sunlight.

Maternal vitamin D status: implications for the development of infantile nutritional rickets

The mother is the major source of circulating 25-hydroxyvitamin D concentration in the young infant. Maternal vitamin D status is an important factor in determining the vitamin D status of the infant and their risk of developing vitamin D deficiency and infantile nutritional rickets. There is evidence that the current supplementation recommendations, particularly for pregnant and lactating women, are inadequate to ensure vitamin D sufficiency in these groups. A widespread and concerted effort is needed to ensure daily supplementation of breastfed and other infants at high risk with vitamin D 400 IU from birth and of pregnant women in high-risk communities with 2000 IU. Future studies are required to determine the optimal doses of vitamin D supplementation in pregnancy and during lactation, and for normalizing vitamin D stores in infancy to reduce the prevalence of infantile nutritional rickets. Operational research studies are needed to understand the best methods of implementing supplementation programs and the factors that are likely to impede their success.

Nutritional rickets and vitamin D deficiency in infants, children and adolescents

Nutritional rickets continues to be a public health problem in many countries despite the presence of cheap and effective means of preventing the disease. Deficiency of vitamin D is associated with rickets in growing children and osteomalacia in adults. Vitamin D deficiency is attributed to a variety of causes including diet, atmospheric pollution, religious practices that restrict sunlight exposure (clothing), geographic latitude and altitude, season, and time of the day. The clinical findings of rickets can vary among stages of the disease. It is recommended that healthy infants, children and adolescents take at least 400 IU vitamin D per day to prevent rickets and vitamin D deficiency. Pediatricians and other healthcare professionals should try to ensure that children and adolescents receive daily vitamin D requirements appropriate for their risk factors, traditions, and customs. Additionally, it is important to use every opportunity to ensure that effective preventive strategies are put in practice.