Predictors of vitamin D status and its association with parathyroid hormone in young New Zealand children.

BACKGROUND: Despite increased awareness of the adverse health effects of low vitamin D status, few studies have evaluated 25-hydroxyvitamin D [25(OH)D] status in young children. OBJECTIVES: We aimed to assess vitamin D status on the basis of 25(OH)D and its relation with parathyroid hormone (PTH) and to identify possible predictors of 25(OH)D status in young children living in a country with minimal vitamin D fortification. DESIGN: Serum 25(OH)D and PTH concentrations were measured in a cross-sectional sample of children aged 12-22 mo [n = 193 for 25(OH)D, n = 144 for PTH] living in Dunedin, New Zealand (latitude: 45 degrees S). Anthropometric, dietary, and sociodemographic data were collected. RESULTS: The majority of children sampled in the summer (94%; 47 of 50) had 25(OH)D >50 nmol/L; however, nearly 80% of children sampled in the winter (43 of 55) had serum concentrations 60-65 nmol/L, a plateau in PTH was evident. CONCLUSIONS: Seasonal variation in 25(OH)D concentration implies that postsummer vitamin D stores were insufficient to maintain status >50 nmol/L year-round. Examination of the predictors of 25(OH)D in our model shows few modifiable risk factors, and thus effective dietary strategies may be required if future research determines that children with 25(OH)D concentrations <50 nmol/L are at significant health risk. This trial was registered at www.actr.org.au as ACTRN12605000487617

A practical approach to vitamin and mineral supplementation in food allergic children

The management of food allergy in children requires elimination of the offending allergens, which significantly contribute to micronutrient intake. Vitamin and mineral supplementation are commonly suggested as part of dietary management. However a targeted supplementation regime requires a complete nutritional assessment, which includes food diaries. Ideally these should be analysed using a computerised program, but are very time consuming. We therefore set out to evaluate current practice of vitamin and mineral supplementation in a cohort of children with non-Immunoglobulin E (IgE) mediated food allergies

Vitamin D in autoimmunity: Molecular mechanisms and therapeutic potential

Over the last three decades, it has become clear that the role of vitamin D goes beyond the regulation of calcium homeostasis and bone health. An important extraskeletal effect of vitamin D is the modulation of the immune system. In the context of autoimmune diseases, this is illustrated by correlations of vitamin D status and genetic polymorphisms in the vitamin D receptor with the incidence and severity of the disease. These correlations warrant investigation into the potential use of vitamin D in the treatment of patients with autoimmune diseases. In recent years, several clinical trials have been performed to investigate the therapeutic value of vitamin D in multiple sclerosis, rheumatoid arthritis, Crohn's disease, type I diabetes, and systemic lupus erythematosus. Additionally, a second angle of investigation has focused on unraveling the molecular pathways used by vitamin D in order to find new potential therapeutic targets. This review will not only provide an overview of the clinical trials that have been performed but also discuss the current knowledge about the molecular mechanisms underlying the immunomodulatory effects of vitamin D and how these advances can be used in the treatment of autoimmune diseases

Cooling in Surgical Patients: Two Case Reports

Moderate induced hypothermia has become standard of care for children with peripartum hypoxic ischaemic encephalopathy. However, children with congenital abnormalities and conditions requiring surgical intervention have been excluded from randomised controlled trials investigating this, in view of concerns regarding the potential side effects of cooling that can affect surgery. We report two cases of children, born with congenital conditions requiring surgery, who were successfully cooled and stabilised medically before undergoing surgery. Our first patient was diagnosed after birth with duodenal atresia after prolonged resuscitation, while the second had an antenatal diagnosis of left-sided congenital diaphragmatic hernia and suffered an episode of hypoxia at birth. They both met the criteria for cooling and after weighing the pros and cons, this was initiated. Both patients were medically stabilised and successfully underwent therapeutic hypothermia. Potential complications were investigated for and treated as required before they both underwent surgery successfully. We review the potential side effects of cooling, especially regarding coagulation defects. We conclude that newborns with conditions requiring surgery need not be excluded from therapeutic hypothermia if they might benefit from it

A meta-analysis of the association between pre-eclampsia and childhood-onset Type 1 diabetes mellitus

Aims To review and synthesize the evidence for an increased risk of childhood Type 1 diabetes mellitus in children born to mothers diagnosed with pre-eclampsia during pregnancy.Methods A comprehensive search of the published literature was performed in MEDLINE, Web of Science and EMBASE limited to studies published before August 2010. Crude odds ratios and 95% confidence intervals were calculated from the data reported in each study. Meta-analysis techniques were then used to derive a combined odds ratio and investigate heterogeneity. Sensitivity analyses were conducted by study design, ascertainment of pre-eclampsia and study quality.Results Data were available from 16 studies including 8315 children with Type 1 diabetes. Overall, there was little evidence of an increase in the risk of Type 1 diabetes in children born to mothers who had pre-eclampsia during pregnancy (OR = 1.10, 95% CI 0.96–1.27; P = 0.17). This association did not vary much between studies (I2 = 28%, P for heterogeneity = 0.14). The association was similar in three cohort studies (OR = 1.05, 95% CI 0.77–1.44; P = 0.75) and in seven studies with a low risk of bias (OR = 1.13, 95% CI 0.91–1.40; P = 0.27), but was more marked in 13 studies which ascertained pre-eclampsia from obstetrical records or birth registry data (OR = 1.18, 95% CI 1.03–1.36; P = 0.02).Conclusions This analysis demonstrates little evidence of any substantial increase in childhood Type 1 diabetes risk after pregnancy complicated by pre-eclampsia.<br/

Nonclassical Vitamin D Action

It is becoming increasingly clear that vitamin D has a broad range of actions in the human body. Besides its well-known effects on calcium/phosphate homeostasis, vitamin D influences muscle function, cardiovascular homeostasis, nervous function, and the immune response. Vitamin D deficiency/insufficiency has been associated with muscle weakness and a high incidence of various chronic diseases such as cardiovascular disease, cancer, multiple sclerosis, and type 1 and 2 diabetes. Most importantly, low vitamin D status has been found to be an independent predictor of all-cause mortality. Several recent randomized controlled trials support the assumption that vitamin D can improve muscle strength, glucose homeostasis, and cardiovascular risk markers. In addition, vitamin D may reduce cancer incidence and elevated blood pressure. Since the prevalence of vitamin D deficiency/insufficiency is high throughout the world, there is a need to improve vitamin D status in the general adult population. However, the currently recommended daily vitamin D intake of 5-15 µg is too low to achieve an adequate vitamin D status in individuals with only modest skin synthesis. Thus, there is a need to recommend a vitamin D intake that is effective for achieving adequate circulating 25-hydroxyvitamin D concentrations (>75 nmol/L)

HbA1c levels in schoolchildren with type 1 diabetes are seasonally variable and dependent on weather conditions

Aims/hypothesis: We evaluated seasonal HbA$_{1c}$ changes in children with type 1 diabetes and its relation with measures of weather conditions. Methods: HbA$_{1c}$ changes over more than 3 years were evaluated in type 1 diabetic patients who were younger than 18 years and had diabetes duration of more than 12 months, and correlated with measures of weather conditions (ambient temperature, hours of sunshine and solar irradiance). After comparison of autocorrelation patterns, patterns of metabolic control and meteorological data were evaluated using Spearman rank correlation. Results: A total of 3,935 HbA$_{1c}$ measurements in 589 school (≥7 years) and 88 preschool (<7 years) children were analysed. Mean (±SD) HbA$_{1c}$ level for the whole study period was 7.65±1.12%. The lowest HbA$_{1c}$ levels were observed in late summer and the highest in winter months, with differences consistently exceeding 0.44%. Autocorrelation analysis of HbA$_{1c}$ levels in schoolchildren showed a sine-wave pattern with a cycle length of roughly 12 months, which mirrored changes in ambient temperature. Strong negative correlations of HbA$_{1c}$ with ambient temperature (R=−0.56; p=0.0002), hours of sunshine (R=−0.52; p=0.0007) and solar irradiance (R=−0.52; p=0.0006) were present in schoolchildren, but not in preschoolers (p≥0.29 for each correlation). Conclusions/interpretation: Seasonal changes of HbA$_{1c}$ levels in schoolchildren with type 1 diabetes are a significant phenomenon and should be considered in patient education and diabetes management. They may potentially affect the results of clinical trials using HbA$_{1c}$ levels as their primary outcome, as well as HbA$_{1c}$-based diagnosis of diabetes

Seasonal variation in month of diagnosis in children with type 1 diabetes registered in 23 European centers during 1989-2008: little short-term influence of sunshine hours or average temperature

Background: The month of diagnosis in childhood type 1 diabetes shows seasonal variation. Objective: We describe the pattern and investigate if year-to-year irregularities are associated with meteorological factors using data from 50 000 children diagnosed under the age of 15 yr in 23 population-based European registries during 1989–2008. Methods: Tests for seasonal variation in monthly counts aggregated over the 20 yr period were performed. Time series regression was used to investigate if sunshine hour and average temperature data were predictive of the 240 monthly diagnosis counts after taking account of seasonality and long term trends. Results: Significant sinusoidal pattern was evident in all but two small centers with peaks in November to February and relative amplitudes ranging from ±11 to ±38% (median ±17%). However, most centers showed significant departures from a sinusoidal pattern. Pooling results over centers, there was significant seasonal variation in each age-group at diagnosis, with least seasonal variation in those under 5 yr. Boys showed greater seasonal variation than girls, particularly those aged 10–14 yr. There were no differences in seasonal pattern between four 5-yr sub-periods. Departures from the sinusoidal trend in monthly diagnoses in the period were significantly associated with deviations from the norm in average temperature (0.8% reduction in diagnoses per 1 °C excess) but not with sunshine hours. Conclusions: Seasonality was consistently apparent throughout the period in all age-groups and both sexes, but girls and the under 5 s showed less marked variation. Neither sunshine hour nor average temperature data contributed in any substantial way to explaining departures from the sinusoidal pattern