Can the sunshine vitamin shed light on type 1 diabetes?

Vitamin D, pregnancy and caries in children in the INMA-Asturias birth cohort

BACKGROUND

Vitamin D is traditionally associated with the metabolism of calcium and phosphorus, a process essential for the mineralization of hard tissue such as bone or tooth. Deficiency of this vitamin is a problem worldwide, however. Given the possibly significant role of Vitamin D in odontogenesis in children, the objective of our study was to determine the influence of vitamin D levels in the blood on dental anomalies in children between 6 and 10 years of age, by means of 25-hydroxy vitamin D tests performed during pregnancy and the first years of life.

METHODS

The data analyzed were sourced from data belonging to the INMA-Asturias birth cohort, a prospective cohort study initiated in 2004 as part of the INMA Project. The 25-hydroxy vitamin D (25(OH)D) test was performed with samples from 188 children in the INMA-Asturias birth cohort with a dental examination performed between 6 and 10 years of age. The samples were taken at three stages: in the mother at 12 weeks of gestation, and subsequently in the child at 4 and 8 years of age. Diet, nutritional and oro-dental hygiene habits were also analyzed by means of questionnaires.

RESULTS

The results indicate a significant association between caries and correct or incorrect brushing technique. With incorrect brushing technique, the prevalence of caries was 48.89%, but this dropped to 22.38% with correct brushing technique. An association was also found between tooth decay and frequency of sugar intake. The prevalence of caries was 24.54% with occasional sugar intake, but this rose to 56% with regular sugar intake. On the other hand, levels < 20 ng/ml in both mother and child at 8 years of age would also be risk factors (ORgest = 2.51(1.01-6.36) and OR8years = 3.45(1.14-11.01)) for the presence of caries in children. The risk of caries practically tripled where 25(OH) D values were < 20 ng/ml.

CONCLUSIONS

Although incorrect brushing technique and regular sugar consumption was found to be the main cause of caries in the children, the low concentrations of vitamin D in the blood of the pregnant mothers may have magnified this correlation, indicating that the monitoring of vitamin D levels during pregnancy should be included in antenatal programmes. It is particularly striking that 50% of the children were deficient in vitamin D at the age of 4, and that dental floss was practically absent from regular cleaning routines.

Confirmation and Identification of Biomarkers Implicating Environmental Triggers in the Pathogenesis of Type 1 Diabetes

Multiple environmental triggers have been proposed to explain the increased incidence of type 1 diabetes (T1D). These include viral infections, microbiome disturbances, metabolic disorders, and vitamin D deficiency. Here, we used ELISA to examine blood plasma from juvenile T1D subjects and age-matched controls for the abundance of several circulating factors relevant to these hypotheses. We screened plasma for sCD14, mannose binding lectin (MBL), lipopolysaccharide binding protein (LBP), c-reactive protein (CRP), fatty acid binding protein 2 (FABP2), human growth hormone, leptin, total adiponectin, high molecular weight (HMW) adiponectin, total IgG, total IgA, total IgM, endotoxin core antibodies (EndoCAbs), 25(OH) vitamin D, vitamin D binding protein, IL-7, IL-10, IFN-γ, TNF-α, IL-17A, IL-18, and IL-18BPa. Subjects also were tested for prevalence of antibodies targeting adenovirus, parainfluenza 1/2/3, Coxsackievirus, cytomegalovirus, Epstein-Barr virus viral capsid antigen (EBV VCA), herpes simplex virus 1, and Saccharomyces cerevisiae. Finally, all subjects were screened for presence and abundance of autoantibodies targeting islet cell cytoplasmic proteins (ICA), glutamate decarboxylase 2 (GAD65), zinc transporter 8 (ZNT8), insulinoma antigen 2 (IA-2), tissue transglutaminase, and thyroid peroxidase, while β cell function was gauged by measuring c-peptide levels. We observed few differences between control and T1D subjects. Of these, we found elevated sCD14, IL-18BPa, and FABP2, and reduced total IgM. Female T1D subjects were notably elevated in CRP levels compared to control, while males were similar. T1D subjects also had significantly lower prevalence of EBV VCA antibodies compared to control. Lastly, we observed that c-peptide levels were significantly correlated with leptin levels among controls, but this relationship was not significant among T1D subjects. Alternatively, adiponectin levels were significantly correlated with c-peptide levels among T1D subjects, while controls showed no relationship between these two factors. Among T1D subjects, the highest c-peptide levels were associated with the lowest adiponectin levels, an indication of insulin resistance. In total, from our examination we found limited data that strongly support any of the hypotheses investigated. Rather, we observed an indication of unexplained monocyte/macrophage activation in T1D subjects judging from elevated levels of sCD14 and IL-18BPa. These observations were partnered with unique associations between adipokines and c-peptide levels among T1D subjects.

Prevalence and Risk Factors of Hypovitaminosis-D in Children with Cognitive and Movement Disorders

OBJECTIVES

To document the prevalence of hypovitaminosis-D in children with intellectual and movement disorders and to identify the risk factors in vitamin D deficient children.

METHODS

This is a cross-sectional study on 90 children with neurodevelopmental disabilities. The prevalence of hypovitaminosis-D and the risk factors such as sun exposure, age-appropriate mobility, diet, skin color and anti-epileptic medications were examined in children with cognitive disorders and movement disorders.

RESULTS

The mean serum vitamin D level in children with cognitive disability (n = 46) was found to be 26.7 ± 16.3 ng/L and in the children with movement disability (n = 44) it was 27.9 ± 10.5 ng/L. Though the risk factors were found in greater numbers in children in the deficient group (vitamin D < 30 ng/L), the difference between the two groups was not significant. Of the 90 children, 86 (95.5%) had at least one sign of vitamin D deficiency. Lowest levels of vitamin D were seen in autistic spectrum disorder and learning disabilities in the Cognitive Disability group and hemiplegia in the Movement Disability group.

CONCLUSIONS

The prevalence of vitamin D deficiency in children with neurodevelopmental disabilities was 72.2%, with 76.1% in the cognitive disability group and 68.2% in the movement disability group. The risk factors were more common in vitamin D deficient children.

Beneficial Effect of Oligofructose-Enriched Inulin on Vitamin D and E Status in Children with Celiac Disease on a Long-Term Gluten-Free Diet: A Preliminary Randomized, Placebo-Controlled Nutritional Intervention Study

Prebiotics have been shown to improve absorption of some nutrients, including vitamins. This pilot study evaluated the effect of the prebiotic oligofructose-enriched inulin (Synergy 1) on fat-soluble vitamins status, parathormone, and calcium-related elements in pediatric celiac disease (CD) patients (n = 34) on a strict gluten-free diet (GFD). Participants were randomized into a group receiving 10 g of Synergy 1 or placebo (maltodextrin) together with a GFD. At baseline and after 3 months of intervention, 25-hydroxyvitamin D [25(OH)D], parathormone, vitamin E and A, calcium, phosphate, magnesium, total protein, and albumin were determined. Concentration of 25(OH)D increased significantly (p < 0.05) by 42% in CD patients receiving Synergy 1 in GFD, whereas no change was observed in placebo. Vitamin D status reached an optimal level in 46% of patients receiving Synergy 1. No significant difference in parathormone, calcium, and phosphate levels was observed. Concentration of vitamin E increased significantly (p < 0.05) by 19% in patients receiving Synergy 1, but not in the placebo. Vitamin A levels were not changed. Supplementation of GFD with Synergy 1 improved vitamin D and vitamin E status in children and adolescents with CD and could be considered a novel complementary method of management of fat-soluble vitamins deficiency in pediatric CD patients.

Vitamin D deficiency and mild to moderate anemia in young North Indian children: A secondary data analysis

OBJECTIVES

The aim of this study was to examine the association between vitamin D deficiency and anemia status among young children in the resource-poor setting of northern urban India.

METHODS

We used data from a randomized controlled trial of daily supplementation with folic acid, vitamin B₁₂, or both for 6 mo in children 6 to 30 mo of age conducted in Delhi, India. We measured serum vitamin D status, hemoglobin, plasma vitamin B₁₂, folate, soluble transferrin receptor, and homocysteine levels at baseline. Children with severe anemia (hemoglobin [Hgb] <7 g/dL) were excluded from enrollment. Multivariable logistic and multinomial logistic regressions were used to examine the association between vitamin D and anemia status at baseline.

RESULTS

25-Hydroxyvitamin-D (25 OHD) concentration was measured for 960 (96%) children. Of the children, 331 (34.5%) were vitamin-D deficient (<10 ng/mL). Approximately 70% of the enrolled children were anemic, with ∼46% having moderate (Hgb 7-9.9 g/dL) and 24% mild (Hgb 10-10.9 g/dL) anemia. There was no association between vitamin D and anemia status after adjusting for confounders; however, the risk for moderate anemia was significantly higher among vitamin D-deficient children than those who were vitamin-D replete (relative risk, 1.58; 95% confidence interval, 1.09-2.31).

CONCLUSIONS

Vitamin D deficiency was associated with moderate anemia among young children and the effect was independent of iron deficiency. The causal association of vitamin D deficiency with anemia risk remains debatable. The role of vitamin D in risk for anemia needs to be examined in further studies.

Hypovitamininosis D in Childhood Cancer Survivors: Importance of Vitamin D Supplementation and Measurement Over Different Points of Time

This observational retrospective cross-sectional and case-controlled study measures levels of 25-hydroxy-vitamin D (25-OH-VD) in pediatric cancer survivors at different intervals and assesses the effect of 2 supplementation regimens over a period of 12 months. Sixty-eight patients were included in this quasi-experimental study, of which 32 were boys and 36 were girls. A control group of 30 healthy children were included. It was found that initial 25-OH-VD levels were insufficient (<30 ng/mL) in 61 patients (89.7%). Yet, no significant difference between the levels of 25-OH-VD in these patients as compared with the healthy control group was evidenced. However, 25-OH-VD levels were significantly higher at 18 months in patients who were supplemented with oral 50,000 IU/month vitamin D during the 12 months in comparison with patients supplemented with 1000 IU/day. Our findings indicate that pediatric cancer survivors who require frequent monitoring of their 25-OH-VD levels yielded better results when supplemented with higher doses of vitamin D over longer periods of time. A course of oral vitamin D supplementation regimen of 50,000 IU/month gave effective results with excellent compliance and no reports of any adverse or harmful effects.

Vitamin-D status and neurodevelopment and growth in young north Indian children: a secondary data analysis

Background

Vitamin-D deficiency has been linked with impaired development in animal studies; however, the evidence from human studies is scanty. Evidence as to whether vitamin-D deficiency during early childhood affects growth is also limited and conflicting. We examined the extent to which vitamin-D deficiency (<10 ng/ml) is associated with neurodevelopment and physical growth in young children.

Methods

We used data from a randomized controlled trial (RCT) of daily folic acid and/ or vitamin B12 supplementation for six months in children aged 6 to 30 months conducted in Delhi, India. We measured vitamin-D status and  neurodevelopment by the Ages and Stages Questionnaire-3 (ASQ-3) at 12 to 36 months of age. Multiple logistic and linear regressions were used to examine the association between vitamin-D deficiency at baseline and neurodevelopment and growth 6 months follow-up.

Results

25-hydroxy-vitamin-D (25OHD) concentration was measured at baseline for 960 (96%) children. Of these, 331 (34.5%) children were vitamin-D deficient. The total and subscale (except for the Personal social scale) ASQ-3 scores, were not different between the vitamin-D deficient and non-deficient children. Vitamin-D deficiency was also not associated with physical growth at baseline and at follow -up.

Conclusion

Our data do not support the hypothesis that vitamin-D deficiency is associated with poor growth and neurodevelopment.

Trial registration

NCT00717730 and CTRI/2010/091/001090. Date of registration: 08 October, 2010

Vitamin D and Parathyroid Hormone Status in Female Garment Workers: A Case-Control Study in Bangladesh

Despite the abundant sunlight, vitamin D deficiency is prevalent in South Asian countries including Bangladesh. Information on vitamin D level is insufficient in adults particularly in female garment workers in Bangladesh. This study was designed to evaluate the status of vitamin D, parathormone (PTH), calcium, and alkaline phosphatase (ALP) among the female garment workers in Bangladesh. Blood samples were collected from female garment workers (n = 40, case group) and general female workers (n = 40, control group) in Dhaka. Serum vitamin D, PTH, calcium, and ALP were measured by chemiluminescence microparticle immunoassay. The mean level of vitamin D was significantly (p < 0.001) lower in case (14.2 ± 2.6 ng/mL) than in the control (22.4 ± 2.4 ng/mL) group. No significant difference was found at mean of PTH and calcium between case (33.9 ± 17.2 pg/mL; 9.1 ± 0.6 mg/dL, resp.) and control (35.9 ± 16.3 pg/mL; 9.3 ± 0.6 mg/dL, resp.) group. The mean ALP in case (117.2 ± 14.4 U/L) group was significantly (p < 0.001) higher than the control group (80.5 ± 30.6 U/L). Overall, PTH level did not show significant correlation with vitamin D. However, calcium and ALP levels showed a significant positive (p < 0.05) and negative (p < 0.001) correlation with vitamin D, respectively. This study indicates a high prevalence of vitamin D deficiency in the female garment workers in Bangladesh.

Vitamin-D deficiency predicts infections in young north Indian children: A secondary data analysis

Background

Recent studies have demonstrated a relationship between poor vitamin D status and respiratory infections and diarrhea among young children. Acute lower respiratory infections (ALRI) and diarrhea are among the two most important causes of death in under-5 children. In this paper, we examined the extent to which vitamin-D deficiency (<10 ng/ml) predicts ALRI, clinical pneumonia and diarrhea among 6 to 30 months old children.

Methods

We used data from a randomized controlled trial (RCT) of daily folic acid and/or vitamin B12 supplementation for six months in 6 to 30 months old children conducted in Delhi, India. Generalized estimating equations (GEE) were used to examine the associations between vitamin-D deficiency and episodes of ALRI, clinical pneumonia and diarrhea.

Results

Of the 960 subjects who had vitamin-D concentrations measured, 331(34.5%) were vitamin-D deficient. We found, after controlling for relevant potential confounders (age, sex, breastfeeding status, wasting, stunting, underweight, anemia status and season), that the risk of ALRI was significantly higher among vitamin-D deficient (OR 1.26; 95% CI: 1.03 to 1.55) compared to vitamin-D-replete children in the six months follow-up period. Vitamin-D status was not associated with episodes of diarrhea or clinical pneumonia.

Conclusion

Vitamin-D deficiency is common in young children in New Delhi and is associated with a higher risk of ALRI. The role of vitamin D in Indian children needs to be elucidated in further studies.

Status of Serum Calcium, Vitamin D and Parathyroid Hormone and Hematological Indices Among Lead Exposed Jewelry Workers in Dhaka, Bangladesh

Jewelry utilizes lead either directly or as a base metal. Costume jewelry requires lead before molding and plating the product with valuable metals. Therefore, such ornaments have a great potential to release heavy metals having health hazards. Also, jewelry makers engaged in preparing German silver, an alloy, apply lead in smelting, alloying, rolling and milling silver wires and pieces. The metal is taken up by blood, soft tissues and bone. The biological effects of lead are dependent upon the level and duration of exposure. Lead inhibits three enzymes of heme biosynthesis- δ-amino-levulinic-acid dehydratase (ALAD), coproporphyrin oxidase, and ferrochelatase, impairing heme synthesis and depressing serum level of erythropoietin resulting in decreased hemoglobin synthesis. Lead exposure also affects calcium metabolism and impair the synthesis of Calcitriol. In the present study, jewelry makers from Dhaka, Bangladesh, were shown to have significantly high levels of lead, protein, albumin, and parathormone in their blood, and significantly high amount of zinc-protoporphyrin and δ-amino-levulinic-acid in their urine. The control group, on the other hand showed significantly higher amounts of calcium (both total and ionized form) Vitamin D3 and non-activated erythrocyte ALAD in their blood, along with hemoglobin. It might be due to inhibition of 1-α-hydroxylase enzyme in renal tubules. Lead causes nephro-toxicity and inhibits 1-α- hydroxylase enzyme leading to decreased calcitriol synthesis resulting in impaired calcium absorption across gastro-intestinal tract and renal tubules. Low Vitamin D3 and significantly increased Parathyroid hormone (PTH) in study group has been found.

High prevalence of vitamin D deficiency in 2-17 year olds presenting with acute fractures in southern Australia

AIM

To determine vitamin D deficiency risk and other lifestyle factors in children aged 2-17 years presenting with an acute fracture to Sunshine Hospital.

METHODS

A prospective observational study was undertaken using a convenience sample data collected from children aged 2-17 years of age presenting with an acute fracture. Recruitment was undertaken over a 3-month period from February to May 2014. Risk factors for vitamin D deficiency (skin pigmentation, hours spent outdoors, sunscreen use and obesity) were identified. Patients providing consent, had measurements of serum 25-hydroxyvitamin D (25-OHD). Vitamin D deficiency was defined as < 50 nmol/L.

RESULTS

Of the 163 patients recruited into this study, 134 (82%) had one or more risk factor(s) for vitamin D deficiency. Of these, 109 (81%) consented to 25-OHD testing, with a median of 53 nmol/l (range 14-110 nmol/l) obtained. A total of 57 (52% at risk, 35% of total participants) were found to be vitamin D deficient. 45 (80%) had mild deficiency (30-50 nmol/l) and 11 (20%) had moderate deficiency (12.5-29 nmol/l).

CONCLUSIONS

One third of all participants, and the majority participants who had one or more risk factor(s) for vitamin D deficiency, were vitamin D deficient. Based on our findings we recommend that vitamin D status be assessed in all children with risk factor of vitamin D deficiency living in urban environments at higher latitudes presenting with fractures. The effect of vitamin D status on fracture risk and fracture healing in children and teenagers is yet to be determined, as do the effects of vitamin D supplementation in vitamin D deficient paediatric patients presenting with acute fracture.

Expression-Based Genome-Wide Association Study Links Vitamin D-Binding Protein With Autoantigenicity in Type 1 Diabetes

Type 1 diabetes (T1D) is caused by autoreactive T cells that recognize pancreatic islet antigens and destroy insulin-producing β-cells. This attack results from a breakdown in tolerance for self-antigens, which is controlled by ectopic antigen expression in the thymus and pancreatic lymph nodes (PLNs). The autoantigens known to be involved include a set of islet proteins, such as insulin, GAD65, IA-2, and ZnT8. In an attempt to identify additional antigenic proteins, we performed an expression-based genome-wide association study using microarray data from 118 arrays of the thymus and PLNs of T1D mice. We ranked all 16,089 protein-coding genes by the likelihood of finding repeated differential expression and the degree of tissue specificity for pancreatic islets. The top autoantigen candidate was vitamin D-binding protein (VDBP). T-cell proliferation assays showed stronger T-cell reactivity to VDBP compared with control stimulations. Higher levels and frequencies of serum anti-VDBP autoantibodies (VDBP-Abs) were identified in patients with T1D (n = 331) than in healthy control subjects (n = 77). Serum vitamin D levels were negatively correlated with VDBP-Ab levels in patients in whom T1D developed during the winter. Immunohistochemical localization revealed that VDBP was specifically expressed in α-cells of pancreatic islets. We propose that VDBP could be an autoantigen in T1D.

Impact of the birth's season on the development of celiac disease in Italy

Celiac disease (CD) is an immune-mediated systemic disorder induced by a trigger factor in genetically susceptible individuals. There is emerging evidence about the impact of the month of birth on the development of several autoimmune diseases. Our aim was to investigate whether, in Italian CD children, the season of birth is associated with development of CD later in life. We report a survey conducted at two Italian referral centers for CD in Rome and Bari. The CD database was created to enable retrospective examination of the data of all the consecutive patients, born between 2003 and 2010, who had received a diagnosis of CD. This CD patient group comprising 596 children was compared with a reference group that included all subjects born in the same period and in the same cities (439,990 controls). Overall, there was a summer birth preponderance in CD patients compared to controls (28.2 % of CD patients vs 23.0 % of the control population; OR 1.315; 95 % CI 1.100 to 1.572). Stratifying the caseload by gender and age, the summer birth preponderance was maintained for females (28.6 % CD females vs 22.6 % control females; OR 1.368; 95 % CI 1.069 to 1.750).

CONCLUSIONS

our survey confirms that in Italy, children born in summer are at higher risk to develop CD than subjects born in other seasons. The identification of a responsible seasonal factor or factors, such as timing of the first introduction of gluten and/or acute viral gastrointestinal infections, would be very important for disease prevention strategies.

WHAT IS KNOWN

• Environmental factors could be involved in the pathogenesis of CD. • Data about the impact of season of birth on CD development is so far derived from North American, Northern European and Israeli surveys.

WHAT IS NEW

• This is the first study in Southern Europe to find a relationship between season of birth (summer) and development of CD. • Summer-born infants are introduced to complementary feeding (gluten) in winter, when the rotavirus infection is at its highest peak; this may be the link between season of birth and development of CD.

Vitamin D insufficiency and deficiency in pediatric renal transplant recipients

Vitamin D deficiency is prevalent in the pediatric CKD population. Recognizing that renal transplant recipients have CKD, we assessed the prevalence of vitamin D insufficiency and deficiency in pediatric renal transplant recipients, compared to a healthy pediatric population. We prospectively studied 25(OH)D levels in 29 pediatric renal transplant recipients and 45 control patients over one yr. The overall prevalence of vitamin D insufficiency and deficiency was common in both populations, at 76% (95% CI: 61, 87%) in the pediatric renal transplant recipients and 91% (95% CI: 80, 98%) in the control group. In the paired renal transplant samples, the mean 25(OH)D level was 52.3 ± 17.9 nmol/L in the winter and 65.6 ± 18.8 nmol/L in the summer (95% CI diff.: 3.9, 22.7), in keeping with a significant seasonal difference. The mean dietary intake of vitamin D in the renal transplant recipients, assessed by three-day dietary record, was 5.7 μg/day, with a vitamin D intake below the EAR in the majority. We did not find an association between vitamin D intake and 25(OH)D levels in this study, likely due to the low dietary intake of vitamin D within the transplant population, identifying a potential area for intervention and improvement.

[Vitamin A and D status among child participants in a food supplementation program]

Vitamin A and D serum concentrations and risk factors for their deficiencies were investigated in children participating in a government-sponsored fortified milk program. The study used multivariate linear regression analysis with hierarchical selection of independent variables: socio-demographic conditions, children's health, food consumption, breastfeeding, fortified milk, exposure to sunlight, anthropometric measurements, and serum concentration of retinol and 25(OH)D. Vitamin A and vitamin D insufficiency and deficiency values were defined as < 1.05 µmol/L, < 0.7 µmol/L, < 30 ng/mL, and < 20 ng/mL, respectively. Vitamin A and D intake was inadequate. Prevalence rates for vitamin A and vitamin D insufficiency and deficiency were 19%, 6%, 82%, and 58%, respectively. Factors associated with low serum vitamin A were exclusive breastfeeding for less than 120 days, low maternal schooling, maternal unemployment, more consumers of fortified milk in the family, and low serum vitamin D. Factors associated with vitamin D deficiency were low exposure to sunlight and low serum vitamin A. Nutritional education is needed to improve children's nutritional status.

Epilepsy treatment by sacrificing vitamin D

Epilepsy is one of the most common neurologic disorders in childhood that often requires long term treatment with antiepileptic drugs. Both antiepileptic treatment and the comorbidities associated with epilepsy have a negative impact on bone health in growing children. Given the fact that vitamin D deficiency is a major public health problem worldwide, clinicians caring for children with chronic diseases should be aware of effects of the medication on the bone metabolism. Yet, vitamin D deficiency due to antiepileptic treatment is an overlooked issue among neurologists. In this review, we briefly describe vitamin D metabolism and the effect of vitamin D in the brain. We also discuss the literature in terms of vitamin D deficiency and antiepileptic treatment in the pediatric population.

Comparison of ground-based measurements of solar UV radiation at four sites on the Tibetan Plateau

We compare results for the UV index (UVI), the total ozone column (TOC), and the radiation modification factor (RMF, being 1 in the absence of clouds and aerosols) at four sites on the Tibetan Plateau. The results were obtained by analyzing ground measurements by multichannel moderate-bandwidth filter instruments for the period July 2008-September 2010, and radiative transfer modeling was used to aid the interpretation of the results. The highest UVI of 20.6 was measured in Tingri (28.7°N; 4335 m). For July, monthly mean UVI values were 14.5 and 12.9 in Tingri and Lhasa (29.7°N; 3683 m), respectively. Generally, the UVI levels in Tingri and Lhasa were higher than in Nagchu (31.5°N; 4510 m) and Linzhi (29.7°N; 2995 m), due to less cloud cover at the former two sites. In 2009, the annual mean UVI and RMF values were 6.8 and 0.7 for Linzhi, 8.8 and 0.92 for Lhasa, 10.5 and 0.92 for Tingri, and 6.7 and 0.7 for Nagchu. Radiative transfer simulations indicate that the latitude difference would correspond to an increase in the UVI of about 0.3 from Nagchu to Tingri; whereas, the altitude difference would correspond to a reduction of about 1.5%, implying that the observed difference is due to the difference in cloud cover. The annual mean TOC values were found to be 260-264 Dobson units (DU) in Lhasa, Linzhi, and Nagchu, and 252 DU in Tingri. TOC values in Lhasa were found to agree within 3% with those derived from Ozone Monitoring Instrument (OMI) measurements.

Serum vitamin D levels are lower in Australian children and adolescents with type 1 diabetes than in children without diabetes

Vitamin D is synthesised in the skin through the action of UVB radiation (sunlight), and 25-hydroxy vitamin D (25OHD) measured in serum as a marker of vitamin D status. Several studies, mostly conducted in high latitudes, have shown an association between type 1 diabetes mellitus (T1DM) and low serum 25OHD. We conducted a case-control study to determine whether, in a sub-tropical environment with abundant sunlight (latitude 27.5°S), children with T1DM have lower serum vitamin D than children without diabetes. Fifty-six children with T1DM (14 newly diagnosed) and 46 unrelated control children participated in the study. Serum 25OHD, 1,25-dihydroxy vitamin D (1,25(OH)(2) D) and selected biochemical indices were measured. Vitamin D receptor (VDR) polymorphisms Taq1, Fok1, and Apa1 were genotyped. Fitzpatrick skin classification, self-reported daily hours of outdoor exposure, and mean UV index over the 35 d prior to blood collection were recorded. Serum 25OHD was lower in children with T1DM (n = 56) than in controls (n = 46) [mean (95%CI) = 78.7 (71.8-85.6) nmol/L vs. 91.4 (83.5-98.7) nmol/L, p = 0.02]. T1DM children had lower self-reported outdoor exposure and mean UV exposure, but no significant difference in distribution of VDR polymorphisms. 25OHD remained lower in children with T1DM after covariate adjustment. Children newly diagnosed with T1DM had lower 1,25(OH)(2) D [median (IQR) = 89 (68-122) pmol/L] than controls [121 (108-159) pmol/L, p = 0.03], or children with established diabetes [137 (113-153) pmol/L, p = 0.01]. Children with T1DM have lower 25OHD than controls, even in an environment of abundant sunlight. Whether low vitamin D is a risk factor or consequence of T1DM is unknown.

Relationship between vitamin D, parathyroid hormone, and bone mineral density in elderly Koreans

There is controversy regarding definition of vitamin D inadequacy. We analyzed threshold 25-hydroxyvitamin D (25[OH]D) below which intact parathyroid hormone (iPTH) increases, and examined age- and sex-specific changes of 25(OH)D and iPTH, and association of 25(OH)D and iPTH with bone mineral density (BMD) in elderly Koreans. Anthropometric parameters, serum 25(OH)D and iPTH, lumbar spine and femur BMD by dual-energy radiography absorptiometry (DXA) were measured in 441 men and 598 postmenopausal women. iPTH increased below serum 25(OH) of 36.7 ng/mL in men, but failed to reach plateau in women. Femur neck BMD above and below threshold differed when threshold 25(OH)D concentrations were set at 15-27.5 ng/mL in men, and 12.5-20 ng/mL in postmenopausal women. Vitamin D-inadequate individuals older than 75 yr had higher iPTH than those aged ≤ 65 yr. In winter, age-associated iPTH increase in women was steeper than in summer. In conclusion, vitamin D inadequacy threshold cannot be estimated based on iPTH alone, and but other factors concerning bone health should also be considered. Older people seemingly need higher 25(OH)D levels to offset age-associated hyperparathyroidism. Elderly vitamin D-inadequate women in the winter are most vulnerable to age-associated hyperparathyroidism.

Vitamin D deficiency in children living in Jeddah, Saudi Arabia

OBJECTIVE

Vitamin D deficiency is an unrecognized epidemic and a common health problem worldwide. This study was conducted to evaluate the vitamin D status in children living in Jeddah, Saudi Arabia and to study its relation to various variables.

MATERIALS AND METHODS

A cross-sectional study was conducted in the pediatric clinic in Jeddah Clinic Hospital-Kandarah, Jeddah, KSA, from October through December 2010, in which 510 healthy children aged 4-15 years were enrolled. Serum calcium, phosphorus, alkaline phosphatase and 25-hydroxyvitamin D [25(OH)D] were measured. Dietary vitamin D intake and duration of daily sunlight exposure were determined. 25(OH)D levels <20 ng/mL and <7 ng/mL were defined as relative and severe vitamin D deficiency, respectively.

RESULTS

The mean concentration of 25(OH)D was 13.07 ± 7.81 ng/mL. Seventy subjects (13.72%) had normal 25(OH)D level ranging 20-70 ng/mL. Three hundred (58.82%) had relative 25(OH)D deficiency and 140 (27.45%) had severe deficiency (P=0.000). 220 (43.14%) subjects were males and 290 (56.86%) were females having a statistically significant higher incidence of 25(OH)D deficiency (P=0.019). 54.9% were Saudis, 27.45% were Yemenis and 11.76% were Egyptians. Saudis and Yemenis were more subjected to 25(OH)D deficiency in comparison to Egyptians and other nationalities (P=0.01). There were significant inverse correlations between 25(OH)D levels and bony aches (P=0.000). 56.25% of asymptomatic children had vitamin D deficiency (P=0.000). Duration of sunlight exposure and daily intake of vitamin D had significant effects on serum level of vitamin D (P=0.000).

CONCLUSIONS

A high prevalence of vitamin D deficiency in children living in Jeddah was observed in this study. Vitamin D supplementation of food products can prevent vitamin D deficiency in these children.

Identification of the Biotransformation Products of 2-Ethylhexyl 4-(N,N-Dimethylamino)benzoate

Nowadays, 2-ethylhexyl 4-(N,N-dimethylamino)benzoate (EDP) is one of the most widely used UV filters in sunscreen cosmetics and other cosmetic products. However, undesirable processes such as percutaneous absorption and biological activity have been attributed to this compound. The in vitro metabolism of EDP was elucidated in the present work. First of all, the phase I biotransformation was studied in rat liver microsomes and two metabolites, N,N-dimethyl-p-aminobenzoic acid (DMP) and N-monomethyl-p-aminobenzoic acid (MMP), were identified by GC-MS analysis. Secondly, the phase II metabolism was investigated by means of LC-MS. The investigated reactions were acetylation and glucuronidation working with rat liver cytosol and with both human and rat liver microsomes, respectively. Analogue studies with p-aminobenzoic acid (PABA) were carried out in order to compare the well established metabolic pathway of PABA with the unknown biotransformation of EDP. In addition, a method for the determination of EDP and its two phase I metabolites in human urine was developed. The methodology requires a solid-phase extraction prior to LC-MS analysis. The method is based on standard addition quantification and has been fully validated. The repeatability of the method, expressed as relative standard deviation, was in the range 3.4-7.4% and the limit of detection for all quantified analytes was in the low ng mL(-1) range.

Vitamin D deficiency in children and its management: review of current knowledge and recommendations

Given the recent spate of reports of vitamin D deficiency, there is a need to reexamine our understanding of natural and other sources of vitamin D, as well as mechanisms whereby vitamin D synthesis and intake can be optimized. This state-of-the-art report from the Drug and Therapeutics Committee of the Lawson Wilkins Pediatric Endocrine Society was aimed to perform this task and also reviews recommendations for sun exposure and vitamin D intake and possible caveats associated with these recommendations.

Dietary proteins as environmental modifiers of type 1 diabetes mellitus

Type 1 diabetes is an autoimmune disease in which the patient's immune system destroys the insulin-secreting beta-cells in the pancreatic islets of Langerhans. A majority of cases is thought to occur as a result of gene-environment interactions. The identity of the environmental factors remains unknown mainly because of the difficulty in linking past exposures with later disease development. Overall, the data suggest a model in which individuals develop diabetes by several different pathways, each influenced by numerous genetic and environmental variables. The most investigated environmental factors are diet and viruses. In this review, we examine the evidence that the source of dietary proteins can modify diabetes outcome, describe new approaches to identify candidate diabetes-related dietary agents, examine possible links with gut dysfunction, discuss some of the limitations, and propose a multifactorial model for dietary modification of diabetes. The key to diabetes pathogenesis, its prevention, and the ultimate success of beta-cell replacement therapies lies in understanding how the environment controls disease expression. Dietary proteins could be one of these keys.

Vitamin D, parathyroid hormone levels and bone mineral density in community-dwelling older women: the Rancho Bernardo Study

Vitamin D (25(OH)D) increases the efficiency of intestinal calcium absorption. Low levels of serum calcium stimulate the secretion of parathyroid hormone (PTH), which maintains serum calcium levels at the expense of increased bone turnover, bone loss and increased risk of fractures. We studied the association between 25(OH)D and PTH levels, and their associations with bone mineral density (BMD), bone loss, and prevalence of hip fractures in 615 community-dwelling postmenopausal aged 50-97 years. Mean level of 25(OH)D and PTH were 102.0 nmol/l+/-35.0 nmol/l and 49.4 ng/l+/-23.2 nmol/l, respectively; 49% of women were current hormone therapy users. The overall prevalence of vitamin D insufficiency (25(OH)D<50 nmol/l) was 2%, and prevalence of high PTH levels (>65 ng/l) was 17.4%. In multiple linear regression analyses hip BMD was negatively and independently associated with PTH levels (p=0.04), and positively and independently associated with 25(OH)D levels (p=0.03). There were only 23 women (3.7%) who experienced a hip fracture. In age-adjusted analyses there were no significant differences of 25(OH)D and PTH levels by hip fracture status. Across the entire range of values, the overall correlation between 25(OH)D and PTH was moderate (r=-0.20). However, after the threshold vitamin D level of 120 nmol/l, all PTH values were below 65 ng/l. Further studies are necessary to identify the optimal vitamin D levels necessary to prevent secondary hyperparathyroidism.

VITAMIN D IN HEALTH AND DISEASE: Vitamin D for Health and in Chronic Kidney Disease

Vitamin D is taken for granted and is not appreciated for its importance in overall health and well-being. Vitamin D, known as the sunshine vitamin, is appreciated as being important for the prevention of rickets in children. It is now recognized that vitamin D is important for not only the growing skeleton, but for the maintenance of a healthy musculoskeletal system throughout life. Vitamin D deficiency in adults precipitates and exacerbates osteoporosis and causes the painful bone disease osteomalacia. The revelation that vitamin D is biologically inactive and requires sequential hydroxylations in the liver and kidney to form 1,25-dihydroxyvitamin D helps explain why patients with renal failure are often resistant to vitamin D and suffer from secondary hyperparathyroidism and renal osteodystrophy. In addition to its role in maintaining calcium and phosphorus homeostasis, vitamin D is now being recognized as important for maintaining maximum muscle strength and for the prevention of many chronic diseases, including type I diabetes, multiple sclerosis, rheumatoid arthritis, hypertension, cardiovascular heart disease, and many common cancers. Vitamin D status is best determined by the measurement of circulating levels of 25-hydroxyvitamin D. Vigilance for maintaining a 25-hydroxyvitamin D level of at least 20 ng/ml and preferably 30-50 ng/ml has important benefits for both healthy children and adults, as well as children and adults suffering from chronic kidney disease.

1,25-Dihydroxyvitamin D3 modulates expression of chemokines and cytokines in pancreatic islets: implications for prevention of diabetes in nonobese diabetic mice

1,25-Dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) is an immune modulator that prevents experimental autoimmune diseases. Receptors for 1,25-(OH)(2)D(3) are present in pancreatic beta-cells, the target of an autoimmune assault in nonobese diabetic (NOD) mice. The aim of this study was to investigate the in vivo and in vitro effects of 1,25-(OH)(2)D(3) on beta-cell gene expression and death and correlate these findings to in vivo diabetes development in NOD mice. When female NOD mice were treated with 1,25-(OH)(2)D(3) (5 microg/kg per 2 d), there was a decrease in islet cytokine and chemokine expression, which was accompanied by less insulitis. Complementing these findings, we observed that exposure to 1,25-(OH)(2)D(3) in three cell systems INS-1(E) cell line, fluorescence-activated cell sorting purified rat beta-cells, and NOD-severe combined immunodeficient islets) suppressed IP-10 and IL-15 expression in the beta-cell itself but did not prevent cytokine-induced beta-cell death. This 1,25-(OH)(2)D(3)-induced inhibition of chemokine expression in beta-cells was associated with a decreased diabetes incidence in some treatment windows targeting early insulitis. Thus, although a short and early intervention with 1,25-(OH)(2)D(3) (3-14 wk of age) reduced diabetes incidence (35 vs. 58%, P < or = 0.05), a late intervention (from 14 wk of age, when insulitis is present) failed to prevent disease. Of note, only early and long-term treatment (3-28 wk of age) prevented disease to a major extent (more than 30% decrease in diabetes incidence). We conclude that 1,25-(OH)(2)D(3) monotherapy is most effective in preventing diabetes in NOD mice when applied early. This beneficial effect of 1,25-(OH)(2)D(3) is associated with decreased chemokine and cytokine expression by the pancreatic islets.

Promoting health in type 2 diabetes: nurse-physician collaboration in primary care

The purpose of this study is to examine effects of a nurse-physician collaborative approach to care of patients with type 2 diabetes and to determine possible effect sizes for use in computing sample sizes for a larger study. Forty patients from a family practice clinic with type 2 diabetes were randomly assigned to control or experimental groups. The control group received standard care, whereas the experimental group received standard care plus home visits from a nurse, as well as consultation with an exercise specialist and/or nutritionist. Follow-up continued for 3 months. Clinical end points included standard measures of diabetes activity as well as quality-of-life indicators. Focus group interviews were used to explore patients' responses to the program. Although findings were not statistically significant, a trend toward small to moderate positive effect sizes was found in glycosylated hemoglobin and blood pressure. Quality of life measures also showed a trend toward small to moderate, but nonsignificant, improvements in physical functioning, bodily pain, vitality, social and global functioning, energy, impact of diabetes, and health distress. Focus group interviews indicated a very positive response from patients, who expressed feelings of empowerment. In this study, patients treated with nurse-physician collaboration demonstrated small, but nonsignificant, improvements in blood chemistry after only 3 months. Physical and social functioning, energy, and bodily pain also showed a small improvement. Changes in awareness of effects of diabetes on health and an expressed sense of self-efficacy suggest that effects could be sustainable over the longer term.

Diabetes in the young: a paediatric and epidemiological perspective

The spectrum of diabetes in the young has widened; it now includes monogenic diseases, for example the various forms of permanent and transient neonatal diabetes and MODY as well as the emerging obesity-associated Type 2 diabetes in late childhood, but the main form is still Type 1 diabetes. Age-related major medical, physiological, social and emotional problems make the clinical management of diabetes in children and adolescents a difficult task for the physician and the family. Overall glycaemic control remains moderate or poor despite a treatment schedule, which interferes with several elements of "normal" childhood. There is an up to tenfold geographical variation in the incidence of childhood Type 1 diabetes within Europe with relatively stable incidence rates in some countries (mainly northern), but dynamic increases in incidence in other countries (mainly central European).A number of nongenetic (environmental) factors have been associated with the risk of Type 1 diabetes. Among these, perinatal factors, early nutrition, growth and vaccinations, atopic diseases and vitamin D are discussed in detail. The important interplay between genes, organism and environment is illustrated with new genetic data supporting the importance of environmental pressures in the evolution of this major disease.Although Type 1 diabetes usually accounts for only a minority of the total impact of diabetes in a population, it is the predominant form of the disease in younger age-groups in most developed countries. It is estimated that on an annual basis almost 100 000 children younger than 15 years of age develop Type 1 diabetes worldwide. The autoimmune destruction of the pancreatic beta cells in Type 1 diabetes leads to absolute insulin dependence and a high rate of complications typically occurring at a relatively young age. Therefore, Type 1 diabetes places a particularly heavy burden on the individual, the family and health services.

Health effects from stratospheric ozone depletion and interactions with climate change

The potential health effects of elevated levels of ambient UV-B radiation are diverse, and it is difficult to quantify the risks, especially as they are likely to be considerably modified by human behaviour. Nevertheless epidemiological and experimental studies have confirmed that UV radiation is a definite risk factor for certain types of cataract, with peak efficacy in the UV-B waveband. The causal link between squamous cell carcinoma and cumulative solar UV exposure has been well established. New findings regarding the genetic basis of skin cancer, including studies on genetically modified mice, have confirmed the epidemiological evidence that UV radiation contributes to the formation of basal cell carcinomas and cutaneous melanomas, For the latter, animal models have demonstrated that UV exposure at a very young age is more detrimental than exposure in adulthood. Although suppression of certain immune responses has been recognised following UV exposure, the impact of this suppression on the control of infectious and autoimmune diseases is largely unknown. However, studies on several microbial infections have indicated significant consequences in terms of symptoms or reactivation of disease. The possibility that the immune response to vaccination could be depressed by UV-B exposure is of considerable concern. Newly emerging possibilities regarding interactions between ozone depletion and global climate change further complicate the risk assessments for human health but might result in an increased incidence of cataracts and skin cancer, plus alterations in the patterns of certain categories of infectious and other diseases.

Ultraviolet radiation and health: friend and foe

While excessive exposure to ultraviolet radiation (UVR) is a significant cause of disease burden in Australia and the Western Pacific region, there are well documented beneficial as well as adverse effects of UVR exposure. Ambient UVR levels do not translate directly to personal UVR dose and thus to biological effect - each person's sun-exposure behaviour and pigmentation also play a role. Exposure in childhood may be more important than exposure in adulthood for both beneficial and adverse effects. Stratospheric ozone depletion increases ambient UVR in the UVB wavelength, possibly the most important wavelength for both beneficial and deleterious health effects. There is ongoing research examining the effects of UVR exposure on immune function, including an examination of the possible role of lack of UVR exposure in the aetiology of multiple sclerosis and type 1 diabetes mellitus.