Low levels of vitamin D in North Indian children with newly diagnosed type 1 diabetes

Borkar VV, Devidayal, Verma S, Bhalla AK. Low levels of vitamin D in North Indian children with newly diagnosed type 1 diabetes. Background: To find out whether vitamin D levels are lower in children with newly diagnosed type 1 diabetes (T1D) as compared to non‐diabetic subjects. Methods: Plasma levels of vitamin D (25‐OHD) were measured by high performance liquid chromatography (HPLC) in 50 children aged between 6 and 12 yr within a week of diagnosis of T1D, and in 50 healthy children. Results: The mean levels of vitamin D were significantly lower in patients as compared to their controls [20.02 ± 10.63 ng/mL (50.05 ± 26.57 mmol/L) vs. 26.16 ± 12.28 ng/mL (65.4 ± 30.7 mmol/L), p‐value 0.009]. Twenty‐nine (58%) children in the study group were vitamin D deficient (25‐OHD level < 20 ng/mL or < 50 mmol/L) as compared to only 16 (32%) in the control group. Overall, 43 (86%) diabetic and 38 (76%) healthy children were either vitamin D deficient or insufficient. Conclusion: These results suggest that vitamin D levels are low at the onset of T1D, and they strongly support the need for further clinical studies to prospectively evaluate the effect of vitamin D supplementation on T1D rates in this patient population.     

Vitamin D status,enterovirus infection,and type 1 diabetes in Italian children/adolescents

At the time of the clinical onset of type 1 diabetes (T1D), we investigated 82 pediatric cases in parallel with 117 non‐diabetic controls matched by age, geographic area, and time of collection. The occurrence of an enteroviral infection was evaluated in peripheral blood using a sensitive method capable of detecting virtually all human enterovirus (EV) types. While non‐diabetic controls were consistently EV‐negative, 65% of T1D cases carried EVs in blood. The vitamin D status was assessed by measuring the concentration of 25‐hydroxyvitamin D [25(OH)D] in serum. Levels of 25(OH)D were interpreted as deficiency (≤50 nmol/L), insufficiency (52.5‐72.5 nmol/L), and sufficiency (75‐250 nmol/L). In T1D cases, the median serum concentration of 25(OH)D was 54.4 ± 27.3 nmol/L vs 74.1 ± 28.5 nmol/L in controls (P = .0001). Diabetic children/adolescents showed deficient levels of vitamin D 25(OH)D (ie, 72.5 nmol/L) in 48.8% cases vs 17.9% in non‐diabetic controls (P = .0001). Unexpectedly, the median vitamin D concentration was significantly reduced in virus‐positive vs virus‐negative diabetics (48.2 ± 22.5 vs 61.8 ± 31.2 nmol/L; P = .015), with deficient levels in 58.5% vs 31.0%, respectively. Thus, at the time of clinical onset, EV‐positive cases had reduced vitamin D levels compared with EV‐negative cases. This could indicate either that the virus‐negative children/adolescents had been hit by a non‐infectious T1D‐triggering event, or that children/adolescents with proper levels of vitamin D had been able to rapidly clear the virus. Thus, it would be important to assess whether adequate vitamin D supplementation before or during the prediabetic phase of T1D may counteract the diabetogenic potential of infectious pathogens.     

The association between ketoacidosis and 25(OH)-vitamin D levels at presentation in children with type 1 diabetes mellitus

Background:  There is considerable evidence supporting the role of vitamin D deficiency in the pathogenesis of type 1 diabetes mellitus (T1DM). Vitamin D deficiency is also associated with impairment of insulin synthesis and secretion. There have been no formal studies looking at the relationship between 25(OH)-vitamin D₃ and the severity of diabetic ketoacidosis (DKA) in children at presentation with T1DM.
Objective:  To determine the relationship between measured 25(OH)-vitamin D₃ levels and the degree of acidosis in children at diagnosis with T1DM.
Subjects:  Children presenting with new-onset T1DM at a tertiary children's hospital.
Methods:  25(OH)-vitamin D₃ and bicarbonate levels were measured in children at presentation with newly diagnosed T1DM. Those with suboptimal 25(OH)-vitamin D₃ levels (<50 nmol/L) had repeat measurements performed without interim vitamin D supplementation.
Results:  Fourteen of the 64 children had low 25(OH)-vitamin D₃ levels at presentation, and 12 of these had low bicarbonate levels (<18 mmol/L) (p = 0.001). Bicarbonate explained 20% of the variation in vitamin D level at presentation (partial r² = 0.20, p < 0.001) and ethnic background a further 10% (partial r² = 0.10, p = 0.002). The levels of 25(OH)-vitamin D₃ increased in 10 of the 11 children with resolution of the acidosis.
Conclusions:  Acid–base status should be considered when interpreting 25(OH)-vitamin D₃ levels in patients with recently diagnosed T1DM. Acidosis may alter vitamin D metabolism, or alternatively, low vitamin D may contribute to a child's risk of presenting with DKA.     

25 Hydroxyvitamin D and vitamin E absorption in healthy children and children with chronic intrahepatic cholestasis

Patients with chronic cholestasis have reduced 25-hydroxyvitamin D (25 OHD) and vitamin E levels. We determined serum concentrations of 25 OHD, 1,25-dihydroxyvitamin D [1,25(OH)₂D] and vitamin E before and after oral administration of 10 g/kg body weight 25-hydroxyvitamin D₃ (25 OHD₃) and 100 IU/kg body weight vitamin E, respectively, in 4 patients with intrahepatic cholestasis and 6 healthy children. Vitamin E increased in all controls but in only one of the four patients. In contrast, oral 25 OHD₃ induced a normal rise in circulating 25 OHD and 1,25(OH)₂D. The low serum levels of 25 OHD in the patients before the oral bolus may have been due to inadequate parenteral vitamin D administration and/or to the simultaneous phenobarbital treatment. The latter possibility is supported by the increase of serum 25 OHD into the normal range after withdrawal of phenobarbital in one of the four patients.We conclude that vitamin E has to be supplemented parenterally or in water-soluble oral form. Further studies are necessary to clarify whether high-dose long-term oral 25 OHD₃ supplementation is sufficient to prevent vitamin D deficiency in patients with chronic cholestasis.Abbreviations 25 OHD 25-hydroxyvitamin D - 25 OHD₃ 25-hydroxyvitamin D₃ - 24,25(OH)₂D 24,25-dihydroxyvitamin D - DBP vitamin D binding protein This report was presented in part at the XIX European Symposium on Calcified Tissues in Stockholm, June 1986. This study was supported by the Deutsche Forschungsgemeinschaft Bu-199-9-1     

Prevalence and characteristics of diabetes among Somali children and adolescents living in Helsinki, Finland

Oilinki T, Otonkoski T, Ilonen J, Knip M, Miettinen PJ. Prevalence and characteristics of diabetes among Somali children and adolescents living in Helsinki, Finland. Objective: We compared the prevalence and characteristics of diabetes between Somali and Finnish children in the City of Helsinki. Subjects and methods: Ten Somali and 310 non‐Somali children <16 yr of age were treated for diabetes in Helsinki at the end of 2007. We analyzed autoantibodies, HLA alleles, and serum 25‐hydroxy‐vitamin D [S25(OH)D] concentrations. Results: The prevalence of diabetes was 40/10 000 (95% CI 19–73/10 000) for the Somali children and 37/10 000 (95% CI 33–41/10 000) for the background population. At least one autoantibody was detected in all seven Somali patients sampled within 18 months after the diagnosis. Most Somalis (75%) carried HLA‐conferred susceptibility to type 1 diabetes (T1D), DR3‐DQ2 being the dominating HLA haplotype. Low S25(OH)D levels (<40 nmol/L) were seen in 83% of the Somali patients and in 60% of their siblings. Conclusions: These data show that (i) Somali children have autoimmune diabetes, (ii) the prevalence of T1D is similar among Somali and Finnish children, and (iii) both affected and unaffected Somali children have low concentrations of S25(OH)D.     

Early response to vitamin D2 in children with calcium deficiency rickets

OBJECTIVE: To assess the effect of vitamin D(2) administration on serum vitamin D metabolite concentrations in calcium deficiency rickets. STUDY DESIGN: We administered vitamin D(2), 50,000 IU orally to 16 Nigerian children 15 to 48 months of age with radiographically active rickets. We measured calcium and vitamin D metabolites at baseline and at 1, 3, 7, and 14 days. RESULTS: At baseline, ranges of serum 25-hydroxyvitamin D (25(OH)D) concentrations were 18 to 40 nmol/L (7-16 ng/mL), and 1,25-dihydroxyvitamin D (1,25-(OH)(2)D) concentrations were 290 to 790 pmol/L (120-330 pg/mL). After vitamin D administration, serum 25(OH)D and 1,25(OH)(2)D concentrations rapidly rose and peaked at 2.8 and 1.9 times the baseline values (P < .001), respectively, at 3 days. Positive correlations between 1,25(OH)(2)D and 25(OH)D were strongest at day 3 (r = 0.84, P < .001) and weakest at day 14 (r = 0.41, P = .11). The relationship of 1,25(OH)(2)D with 25(OH)D at baseline and the increase in 1,25(OH)(2)D in response to vitamin D were similar to those described in children with vitamin D deficiency. However, unlike the pattern in vitamin D deficiency, 1,25(OH)(2)D remained positively correlated with 25(OH)D after administration of vitamin D. CONCLUSION: Dietary calcium deficiency increases the demand for 25(OH)D above that required in vitamin D deficiency to optimize 1,25(OH)(2)D concentrations. Assessment of vitamin D sufficiency in persons or communities may need to be adjusted for habitual dietary calcium intake.     

Parathormone--25(OH)-vitamin D axis and bone status in children and adolescents with type 1 diabetes mellitus

Hamed EA, Abu Faddan NH, Adb Elhafeez HA, Sayed D. Parathormone – 25(OH)‐vitamin D axis and bone status in children and adolescents with type 1 diabetes mellitus. Background: Skeletal involvement in patients with type 1 diabetes mellitus (T1DM) has complex pathogenesis and despite numerous researches on this problem, many questions remain unanswered. Objective: This study aimed to assess bone status by measurement parathormone (PTH), 25‐hydroxy vitamin D [25(OH)D] serum levels in children and adolescents with T1DM and its relation to insulin‐like growth factor‐1 (IGF‐1), disease duration, puberty stage, and metabolic control. Patients and methods: This study included 36 children and adolescents with T1DM and 15 apparently healthy controls. Serum levels of 25(OH)D, PTH, IGF‐1 measured using enzyme‐linked immunosorbent assay (ELISA), while glycosylated hemoglobin (HbA1c), calcium (Ca), inorganic phosphorus (PO₄) using autoanalyzer. Bone quality assessed using dual energy X‐ray absorptiometry (DEXA). Results: Diabetic patients showed significant increase in PO₄ and PTH levels, while significant decrease in Ca, IGF‐1, and 25(OH)D serum levels. As much as 52.8% of patients showed reduced 25(OH)D, and 30.65% showed elevated PTH serum levels. In diabetic patients, abnormal bone status (osteopenia‐osteoporosis) found mostly in total body (94.40%) then lumber‐spine (88.90%), ribs (88.90%), pelvis (86.10%), thoracic‐spine (80.60%), arms (80.60%) and legs (77.80%), while head bones showed no abnormalities. Long diabetic duration had negative; meanwhile PTH, onset age, and puberty age had positive impact on bone status. Conclusions: Children and adolescent with T1DM have abnormal bone status mostly in axial skeleton which may be contributed to impairment of formation of 25(OH)D and IGF‐1. Physical activity, calcium and vitamin D supplement seem important in T1DM. Elevated serum PTH level in diabetic patients is not uncommon and its positive correlation with bone status needs further investigations.     

Vitamin D status of White pregnant women and infants at birth and 4 months in North West England: A cohort study

The prevalence of vitamin D deficiency in pregnant white‐skinned women (WSW) and their infants has not been investigated at northern latitudes in a developed county. A 2‐year observational cohort study was undertaken in the North West of England to determine 25‐hydroxyvitamin D (25OHD) levels in WSW and their infants during pregnancy and 4 months postdelivery and to explore factors associated with these levels. Nutritional and lifestyle questionnaires were completed and 25OHD levels measured at 28 weeks and 4 months postdelivery. Twenty‐seven percent and 7% of WSW had insufficient and deficient levels of 25OHD during pregnancy and 48% and 11% four months postdelivery. WSW with Fitzpatrick skin‐type I (FST I) have significantly lower 25OHD than other skin types after controlling for time spent outside and vitamin D intake. Twenty‐four percent and 13% of infants had insufficient and deficient 25OHD levels at 4 months. Unsupplemented breast‐fed infants have the highest level of insufficiency (67%) compared with formula‐fed infants (2%). Factors associated with infant serum 25OHD levels at 4 months included breast feeding, supplementation, and time outside. WSW have a high prevalence of insufficiency and deficiency during pregnancy which doubles 4 months after birth. Breast‐fed infants of WSW are rarely considered at risk of vitamin D insufficiency but have high rates compared with formula‐fed infants. This is the first study to show the finding that FST I WSW have significantly lower levels of 25OHD than those with FST II–IV (difference adjusted for diet and time outside 14 (95%CI 7–21) nmol/L).     

Vitamin D supplementation is associated with higher serum 25OHD in Asian and White infants living in Vancouver,Canada

To prevent rickets, the Health Canada and the American Academy of Pediatrics recommend that breastfed infants receive a daily vitamin D supplement of 10 μg d^?1. Compliance with this recommendation is variable and its effect on infant vitamin D status is unclear. We measured serum 25‐hydroxyvitamin D (25OHD) in Asian immigrant (n = 28) and White (n = 37) mothers and their infants aged 2–4 months living in Vancouver (49°N). Mothers completed health and demographic questionnaires. All subjects were term infants who were primarily breastfed. Analysis of variance, χ², multiple regression and logistic regression analysis were performed as appropriate. Mean 25OHD of the infants was 31 (95% confidence interval 28–34) ng mL^?1. Only two infants had a 25OHD concentration indicative of deficiency, <10 ng mL^?1. Of the infants, 14% (n = 9) and 49% (n = 32) were vitamin D insufficient based on two commonly used cut‐offs of 20 and 30 ng mL^?1, respectively. Fifty‐eight (89%) infants had been given a vitamin D supplement. Mean 25OHD was 9.4 ng mL^?1 higher in infants consuming ≥10 μg d^?1 of vitamin D from supplements vs. those consuming less (P = 0.003). Mother's 25OHD, season, skin colour or ethnicity (Asian vs. White) did not influence infant 25OHD. The infants in our study, most of whom received vitamin D supplements, were generally protected against low 25OHD. The study was limited by sample size and the nature of the cross‐sectional study design.     

Vitamin D at the onset of type 1 diabetes in Italian children

Low vitamin D levels have been reported in multiple immune disorders such as type 1 diabetes mellitus (T1DM). The purpose of our study was to determine vitamin D levels in children at the onset of T1DM compared with children with other diseases and to test the hypothesis that low vitamin D may increase the odds for developing diabetes. All the children (n?=?58) that were consecutively admitted to our clinic at T1DM onset between May 2010 and July 2012 were compared with a control group of children (n?=?166) hospitalized for other diseases, matched for sex, season of visit, and age. For each subject, we considered clinical and anthropometric data, the season at time of hospitalization, and serum 25-hydroxyvitamin D (25(OH)D), which were analyzed and compared using multivariable conditional logistic regression. Median 25(OH)D was significantly lower in the diabetic patients (36.2 nmol/l, range?=?7.5–121.0 nmol/l) than in controls (48.7 nmol/l, range?=?7.5–190.2 nmol/l), p?=?0.010. Low 25(OH)D levels seem to increase the odds for developing T1DM (odds ratio (OR)?=?3.45 for 25(OH)D 51–74 nmol/l, OR?=?5.56 for 25(OH)D?≤?50 nmol/l). There was no seasonal effect on the risk of developing T1DM. Median 25(OH)D level was significantly lower in patients admitted with diabetic ketoacidosis (30.2 nmol/l, range?=?7.5–101.8 nmol/l) than in patients without ketoacidosis (40.7 nmol/l, range?=?15.2–121.1 nmol/l), p?=?0.019; but when adjusted for season, the p value was 0.116. Conclusions: Children at onset of T1DM have lower vitamin D serum levels than those with other diseases. Further longitudinal studies on children before the onset of T1DM will allow clinicians to explore the causal relationship between vitamin D and T1DM.     

Predictors of vitamin D status in New Zealand preschool children

Vitamin D deficiency has adverse health effects in young children. Our aims were to determine predictors of vitamin D status and then to use these factors to develop a practical tool to predict low 25(OH)D concentrations in preschool New Zealand children. A cross‐sectional sample of 1329 children aged 2 to <5 years were enrolled from throughout New Zealand in late‐winter to spring 2012. 25‐Hydroxyvitamin D (25(OH)D) was measured on dried blood spot (DBS) samples collected using finger‐prick sampling. Caregivers completed a questionnaire. Mean (SD) DBS 25(OH)D concentration was 52(19)nmol/L. 25(OH)D < 25 nmol/L was present in 86(7%), 25(OH)D < 50 nmol/L in 642(48%), 25(OH)D 50‐ < 75 nmol/L in 541(41%) and 25(OH)D > 75 nmol/L in 146(11%) of children. Factors independently associated with the risk of 25(OH)D < 25 nmol/L were female gender (OR 1.92,95%CI 1.17–3.14), other non‐European ethnicities (not including Māori or Pacific) (3.51,1.89–6.50), had olive‐dark skin colour (4.52,2.22–9.16), did not take vitamin D supplements (2.56,1.06–6.18), had mothers with less than secondary‐school qualifications (5.00,2.44–10.21) and lived in more deprived households (1.27,1.06–1.53). Children who drank toddler milk (vitamin D fortified cow's milk formula marketed to young children) had a zero risk of 25(OH)D < 25 nmol/L. The predictive tool identified children at risk of 25(OH)D < 25 nmol/L with sensitivity 42%, specificity 97% and ROC area‐under‐curve 0.76(95%CI 0.67–0.86, p < 0.001). Predictors of low vitamin D status were consistent with those identified in previous studies of New Zealand children. The tool had insufficient predictive ability for use in clinical situations, and suggests a need to promote safe, inexpensive testing to determine vitamin D status in preschool children.     

Vitamin D status in Norwegian children and adolescents with excess body weight

Lagunova Z, Porojnicu AC, Lindberg FA, Aksnes L, Moan J. Vitamin D status in Norwegian children and adolescents with excess body weight. Objectives: The prevalence of childhood and adolescent obesity has increased during the past decades. A high body mass index (BMI) is associated with a low vitamin D status. The purpose of this study was to determine the prevalence of vitamin D deficiency and insufficiency in Norwegian children and adolescents with excess body weight. Methods: Vitamin D status and seasonal variations of 25(OH)D and 1,25(OH)₂D were analyzed in 102 children and adolescents (70 girls and 32 boys), 8–19 yr of age, with overweight and obesity. Results: Overall, 50% of the children and adolescents included in the study had a low vitamin D status (25(OH)D <75 nmol/L) and 19% had vitamin D deficiency (25(OH)D <50 nmol/L). This was most prevalent in adolescents. Only 42% of teenagers had 25(OH)D levels ≥75 nmol/L vs. 72% of preteens. Both 25(OH)D and 1,25(OH)₂D showed seasonal variations. A peak in serum 25(OH)D concentrations was observed during the summer while the lowest values were seen during the spring. In contrast, serum 1,25(OH)₂D had a peak during the spring and the lowest concentrations during the winter. Conclusions: The prevalence of vitamin D deficiency and insufficiency is higher in obese and overweight adolescents than in overweight children. This might be related to low outdoor activities and low vitamin D intake in teenagers. Seasonal variations of both the vitamin D metabolites were observed.     

Neurocognitive functioning in preschool‐age children with type 1 diabetes mellitus

Patiño‐Fernández AM, Delamater AM, Applegate EB, Brady E, Eidson M, Nemery R, Gonzalez‐Mendoza L, Richton S. Neurocognitive functioning in preschool‐age children with type 1 diabetes mellitus. Neurocognitive functioning may be compromised in children with type 1 diabetes mellitus (T1DM). The factor most consistently implicated in the long‐term neurocognitive functioning of children with T1DM is age of onset. The pediatric literature suggests that glycemic extremes may have an effect on the neurocognitive functioning of children, but findings are mixed. The purpose of this study was to compare the neurocognitive functioning of young children with T1DM diagnosed before 6 yr of age and healthy children (i.e., without chronic illness). Additionally, in the children with T1DM, we examined the relationship between their neurocognitive functioning and glycemic control. Sixty‐eight (36 with T1DM and 32 without chronic illness) preschool‐age children (M age = 4.4 yr ) were recruited and administered a battery of instruments to measure cognitive, language, and fine motor skills. Children with T1DM performed similar to the healthy controls and both groups' skills fell in the average range. Among children with diabetes, poor glycemic control [higher hemoglobin A1c (HbA1c)] was related to lower general cognitive abilities (r = ?0.44,p < 0.04), slower fine motor speed (r = ?0.64,p < 0.02), and lower receptive language scores (r = ?0.39,p < 0.04). Such findings indicate that young children with T1DM already demonstrate some negative neurocognitive effects in association with chronic hyperglycemia.     

Optimal level of 25‐(OH)D in children in Nanjing (32°N Lat) during winter

Background: The optimal serum level of 25‐hydroxyvitamin D (25‐(OH)D) for bone health is still unclear, especially in children. Hypovitaminosis D is also re‐emerging in developed and developing countries. The purpose of the present study was therefore to determine optimal serum 25‐(OH)D level and preliminarily identify the vitamin D nutritional status in Nanjing children. Methods: All subjects (76 healthy, 66 suffering from infectious diseases) aged 0–10 years were recruited during the period December 2007–March 2008. Venous blood samples were collected before breakfast and the levels of serum 25‐(OH)D, parathyroid hormone (PTH), bone‐specific alkaline phosphatase (BAP), calcium (Ca), phosphorus (P) were determined. The optimal level of serum 25‐(OH)D was explored using the three response curves of 25‐(OH)D versus PTH, 25‐(OH)D versus BAP, and 25‐(OH)D versus Ca×P product. Results: For 25‐(OH)D ≤ 50 nmol/L, PTH and BAP were both inversely correlated with 25‐(OH)D (PTH, r=?0.864, P < 0.01; BAP, r=?0.856, P < 0.01). For 25‐(OH)D > 50–60 nmol/L, levels of PTH and BAP remained steady. With regard to the Ca×P product, for 25‐(OH)D ≤ 50 nmol/L, Ca×P product increased as 25‐(OH)D increased (r= 0.037, P > 0.05). For 25‐(OH)D > 50–60 nmol/L, Ca×P product remained steady. The mean serum level of 25‐(OH)D was 80.5 ± 29.3 nmol/L (mean ± SD) in the healthy children, and 65.7 ± 32.3 nmol/L in the sick children. Conclusion: The optimal 25‐(OH)D level may be 50–60 nmol/L for bone health in Nanjing children. The vitamin D nutritional status of Nanjing children is relatively good in winter.     

Lymphocyte subpopulations in children with vitamin D deficient rickets

Recent studies have shown 1,25(OH)₂D₃-mediated modulation of the immune system. We examined lymphocyte subpopulations of 16 children with nutritional rickets. Most of the patients suffered more frequent infection episodes than the control group of 15 healthy children and low serum levels of 25OHD and 1,25(OH)₂D, such as 38.2 ± 8.6 ng/mL and 15.7 ± 2.6 pg/mL respectively. This decrease correlated with a significant decrease in total T lymphocytes and an increase in B lymphocytes expressing surface IgA, IgM, IgG molecules. These results suggest that vitamin D plays an important role in the impaired functions of T lymphocytes which may lead to frequent infection episodes in nutritional rickets.     

Vitamin D status in children and adolescents with kidney transplants

Hypovitaminosis D is highly prevalent in adult kidney-transplanted patients. The knowledge of vitamin D status in kidney-transplanted children and adolescents is sparse. The present study investigated the vitamin D status of a cohort of kidney-transplanted children and adolescents, and the association between vitamin D status and plasma concentrations of PTH, ionized calcium, and phosphate. The study included 35 patients with a functioning graft. Their mean age was 12.0 yr, and the mean graft age was 2.8 yr. Forty percent of the patients were vitamin D insufficient (P-25-hydroxyvitamin D 40-75 nm), and 14% were deficient (P-25-hydroxyvitamin D < 40 nm). S-25-hydroxyvitamin D was inversely associated with PTH (p = 0.02) and positively associated with S-1,25-dihydroxyvitamin D (p = 0.02). There was no significant association between S-1,25-dihydroxyvitamin D and PTH. In conclusion, we found hypovitaminosis D in 54% of the study population despite the fact that samples were collected in spring and summer months. Hypovitaminosis D was associated with adverse effects on PTH and 1,25-dihydroxyvitamin D. Our data suggest that it is warranted to monitor vitamin D status of kidney-transplanted children and adolescents and indicate that correction of hypovitaminosis D might have favorable effects on calcium-phosphate metabolism.     

Frequency of vitamin D insufficiency in healthy children between 1 and 16 years of age in Turkey

Background: The aim of this study was to establish the frequencies of vitamin D deficiency and insufficiency among healthy children aged 1–16 years and also to determine the factors affecting the levels of vitamin D in Turkey. Methods: A total of 849 healthy individuals whose ages ranged from 1 to 16 years were included in the study. Serum 25(OH)D, calcium, phosphorous and alkaline phosphatase l levels were measured at the end of the winter period. The approximate daily calcium intake was calculated by using a 1‐week diet history. Results: We determined that the prevalence of vitamin D deficiency (<20 ng/mL) was 8% and that of vitamin D insufficiency (20–29 ng/mL) was 25.5% in the population investigated. The average daily intake of calcium was especially low in the >8‐year‐old age group (<1300 mg/day). Conclusion: Vitamin D insufficiency was found to be very common in the population investigated. The daily calcium intake was below the adequate levels especially in school children. Vitamin D supplementation after the first year of life could be beneficial especially for school children and adolescents. The government must develop public policies for the fortification of milk, milk products, and fruit juices with vitamin D.     

Regional differences in infant 25‐Hydroxyvitamin D: Pilot study of the Japan Environment and Children’s Study

Background

In recent years, a resurgence in the number of infants with vitamin D deficiency has been noted. In addition to seasonal differences in exposure to ultraviolet (UV) rays, regional differences in dietary habits and lifestyles may affect susceptibility to vitamin D deficiency. No studies have been conducted, however, on infants in multiple regions of Japan to determine the extent of differences in vitamin D status.

Methods

25‐Hydroxyvitamin D (25OHD) was measured on radioimmunoassay in 126 infants aged 2–4 years, who participated in the Pilot Study of the Japan Environment and Children's Study (JECS) by the Ministry of Environment of Japan. A multiple regression model with 25OHD level as the outcome variable, and season and region as explanatory variables, was generated.

Results

Both region and season during which infants participated in this study significantly affected 25OHD level (P = 0.0087 and <0.0001, respectively; Wald test). Reflecting decreased exposure to UV rays, infants who were examined in winter had lower 25OHD than those examined in summer. Infants from both Fukuoka Prefecture (33°N) and Kumamoto Prefecture (32°N), however, had lower 25OHD than those from Tochigi Prefecture (36°N), contrary to expectations given the extent of UV exposure.

Conclusions

Regional differences in daily habits and/or environmental factors affect 25OHD level in Japanese infants. The JECS is expected to identify those factors to provide guidance on preventing infantile vitamin D deficiency.     

Hypovitaminosis D among healthy adolescent girls attending an inner city school.

AIMS: To determine the prevalence of hypovitaminosis D among healthy adolescent schoolgirls attending an inner city multiethnic girls' school. METHODS: Fifty one (28%) of 182 girls (14 white, 37 non-white; median age 15.3 years, range 14.7-16.6) took part in the study. Biochemical parameters, dietary vitamin D intake, muscle function parameters, duration of daily sunlight exposure (SE), and percentage of body surface area exposed (%BSA) were measured. RESULTS: Thirty seven (73%) girls were vitamin D deficient (25-hydroxyvitamin D (25OHD) <30 nmol/l) and 9 (17%) were severely deficient (25OHD <12.5 nmol/l). The median (range) 25OHD concentration of white girls (37.3 nmol/l (18.3-73.3)) was higher than that of non-white girls (14.8 nmol/l (5.8-42.8)). The median (range) concentration of parathyroid hormone in white girls (2.8 pmol/l (1.0-3.7)) was lower than that of non-white girls (3.4 pmol/l (1.7-34.2)). Serum Ca, inorganic phosphate, alkaline phosphatase, and 1,25-dihydroxyvitamin D were not different in white and non-white girls. For the whole group, 25OHD concentration was related to the estimated SE and %BSA, but not to estimated intake of vitamin D. In white girls, the estimated SE and %BSA were significantly higher than that of non-white girls. The median times taken to complete the Gower's manoeuvre and grip strength were not different in the two groups; these variables were not related to serum 25OHD. CONCLUSIONS: Hypovitaminosis D is common among healthy adolescent girls; non-white girls are more severely deficient. Reduced sunshine exposure rather than diet explains the difference in vitamin D status of white and non-white girls.     

C-peptide in the classification of diabetes in children and adolescents

Ludvigsson J, Carlsson A, Forsander G, Ivarsson S, Kockum I, Lernmark Å, Lindblad B, Marcus C, Samuelsson U. C‐peptide in the classification of diabetes in children and adolescents. Aim: To report C‐peptide results in newly diagnosed patients and the relation to clinical diagnosis of diabetes. Methods: A nation‐wide cohort, the Better Diabetes Diagnosis study was used to determine serum C‐peptide at diagnosis in 2734 children and adolescents. Clinical data were collected at diagnosis and follow‐up. C‐peptide was determined in a validated and controlled time‐resolved fluoroimmunoassay. Results: The clinical classification of diabetes, before any information on human leukocyte antigen, islet autoantibodies, or C‐peptide was received, was type 1 diabetes (T1D) in 93%, type 2 diabetes (T2D) in 1.9%, maturity onset diabetes of the young (MODY) in 0.8%, secondary diabetes (0.6%), while 3.3% could not be classified. In a random, non‐fasting serum sample at diagnosis, 56% of the patients had a C‐peptide value >0.2 nmol/L. Children classified as T2D had the highest mean C‐peptide (1.83 + 1.23 nmol/L) followed by MODY (1.04 ± 0.71 nmol/L) and T1D (0.28 ± 0.25 nmol/L). Only 1/1037 children who had C‐peptide <0.2 nmol/L at diagnosis was classified with a type of diabetes other than T1D. Predictive value of C‐peptide >1.0 nmol/L for the classification of either T2D or MODY was 0.46 [confidence interval 0.37–0.58]. Conclusions: More than half of children with newly diagnosed diabetes have clinically important residual beta‐cell function. As the clinical diagnosis is not always straightforward, a random C‐peptide taken at diagnosis may help to classify diabetes. There is an obvious use for C‐peptide determinations to evaluate beta‐cell function in children with diabetes.