Vitamin D deficiency among native Dutch and first- and second-generation non-Western immigrants

The aim of this study was to determine the prevalence of 25-hydroxyvitamin D (25(OH)D) deficiency in a hospital-based population of both native Dutch and non-Western immigrants and to investigate the influence of immigrant status on the prevalence of vitamin D deficiency. A cross-sectional survey was conducted among 132 patients (1–18 years of age) visiting the paediatric outpatient department. Serum levels of 25(OH)D were measured using high-performance liquid chromatography. Cut-off levels of 30 and 50 nmol/l for serum 25(OH)D were evaluated. One third of the patients had serum 25(OH)D levels below 30 nmol/l, and half of the study population had serum levels below 50 nmol/l. Non-Western immigrants had an increased risk for vitamin D deficiency compared to their native Dutch peers [25(OH)D of <30 nmol/l, p?=?0.03, odds ratio (OR) 3.87 (95 % confidence interval (CI) 1.13–13.29); 25(OH)D of <50 nmol/l, p?=?0.02, OR 3.57 (95 % CI 1.26–10.14)] with the highest risk for first-generation non-Western immigrants. Conclusion: Vitamin D deficiency in the paediatric population is still a matter of concern in the Netherlands, in particular among first-generation non-Western immigrants. We therefore strongly recommend vitamin D supplementation for all non-Western immigrants, regardless of age, skin type or season. Health-care staff who work with non-Western immigrants should be aware of the prevalence and implications of vitamin D deficiency.     

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)₂D) 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)₂D [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.     

Vitamin D status and predictors of hypovitaminosis D in Italian children and adolescents: a cross-sectional study

Hypovitaminosis D affects children and adolescents all around the world. Italian data on vitamin D status and risk factors for hypovitaminosis D during pediatric age are lacking. Six hundred fifty-two children and adolescents (range 2.0–21.0 years) living in the northwestern area of Tuscany were recruited at the Department of Pediatrics, University Hospital Pisa. None of them had received vitamin D supplementation in the previous 12 months. 25-hydroxyvitamin D (25-OH-D) and parathyroid hormone (PTH) levels were analyzed in all subjects. Severe vitamin D deficiency was defined as serum levels of 25-OH-D?<?25.0 nmol/L (10.0 ng/mL) and vitamin D deficiency as?<?50.0 nmol/L (20.0 ng/mL). Serum 25-OH-D levels of 50.0–74.9 nmol/L (20.0–29.9 ng/mL) indicated vitamin D insufficiency, whereas 25-OH-D levels?≥?75.0 nmol/L (30.0 ng/mL) were considered sufficient. Hypovitaminosis D was defined as 25-OH-D levels?<?75.0 nmol/L (30.0 ng/mL). The median serum 25-OH-D level was 51.8 nmol/L, range 6.7–174.7 (20.7 ng/mL, range 2.7–70.0), with a prevalence of vitamin D deficiency, insufficiency, and sufficiency of 45.9, 33.6, and 20.5 %, respectively. The prevalence of severe vitamin D deficiency was 9.5 %. Adolescents had lower median 25-OH-D levels (49.8 nmol/L, range 8.1–174.7; 20.0 ng/mL, range 3.2–70.0) than children (55.6 nmol/L, range 6.8–154.6; 22.3 ng/mL, range 2.7–61.9, p?=?0.006). Non-white individuals (n?=?37) had median serum 25-OH-D levels in the range of deficiency (28.2 nmol/L, range 8.1–86.2; 11.3 ng/mL, range 3.2–34.5), with 36/37 having hypovitaminosis D. Logistic regression showed significant increased risk of hypovitaminosis D in the following: blood samples taken in winter (odds ratio (OR) 27.20), spring (OR 26.44), and fall (OR 8.27) compared to summer; overweight (OR 5.02) and obese (OR 5.36) subjects compared to individuals with normal BMI; low sun exposure (OR 8.64) compared to good exposure, and regular use of sunscreens (OR 7.06) compared to non-regular use. Gender and place of residence were not associated with vitamin D status. The 25-OH-D levels were inversely related to the PTH levels (r?=??0.395, p?<?0.0001). Sixty-three out of the 652 (9.7 %) subjects showed secondary hyperparathyroidism. Conclusion Italian children and adolescents who were not receiving vitamin D supplementation had high prevalence of hypovitaminosis D. Careful identification of factors affecting vitamin D status is advisable to promptly start vitamin D supplementation in children and adolescents.     

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.     

The association of vitamin D status with cardiometabolic risk factors,obesity and puberty in children

Low serum 25-hydroxyvitamin D3 (25(OH)D) levels have been associated with insulin resistance and cardiovascular diseases. The influences of gender, puberty and adiposity on vitamin D status and the relationship between 25(OH)D and cardiometabolic risk factors in obese and non-obese children were studied. A retrospective analysis was carried out on 168 Turkish children during late winter. Age, gender, puberty, body mass index (BMI), 25(OH)D levels and cardiometabolic risk factors including lipid profiles, high-sensitivity C-reactive protein and insulin resistance index calculated by homeostasis model assessment (HOMA-IR) were evaluated. The median age of the study population was 11 (4–16) years, and 102 children (60.7 %) were prepubertal. Overall, 98.2 % of patients had 25(OH)D levels lower than 20 ng/mL (median 10.0 (4.0–21.3) ng/mL). The 25(OH)D levels did not correlate with BMI. However, an inverse correlation was seen between serum 25(OH)D and HOMA-IR (rho?=??0.656, p?=?0.006) and insulin (rho?=??0.715, p?=?0.002) in pubertal obese subjects. Female gender and puberty were all negatively associated with 25(OH)D. Conclusion: The association between vitamin D status and BMI is complex, and it does not seem to be altered by mild obesity. In addition, potential influence of puberty should be kept in mind while assessing the relationship between serum 25(OH)D and cardiometabolic risk factors.     

Vitamin D levels in schoolchildren: a cross-sectional study in Kuwait

Background

Ongoing studies in the Middle East, particularly in the Arabian Gulf countries, have reported extremely low levels of serum vitamin D across age and gender. In Kuwait, vitamin D deficiency is prevalent in adolescent girls and in adult women. A number of risk factors have been reported, among which gender, age, and obesity are a few. Because adequate vitamin D status is necessary to promote bone mineral accrual in childhood, and because low vitamin D levels have been associated with a wide range of health problems, there is concern that growing children with low vitamin D may be at higher risk for developing diseases. The aim of this study was to assess vitamin D levels in elementary schoolchildren.

Methods

Kuwaiti schoolchildren were recruited and assessed for their serum vitamin D, 25(OH)D, parathyroid hormone (PTH) and adjusted serum calcium (adj-Ca). Anthropometric measurements and data on lifestyle and health status were recorded during an interview.

Results

In a total of 199 schoolchildren, median (IQR) age was 8.5 (7.0–9.5 years), 25(OH)D was 30 (22–39 nmol/L), PTH was 4.7 (3.8–5.9 pmol/L), and adj-Ca was 2.39 (2.33–2.44 mmol/L). Boys had higher levels of 25(OH)D (18.3% vs 6.6% had levels ≥50 nmol/L) and lower levels of PTH (94.6% vs 80.2% had levels <7 pmol/L) than girls. Significant risk factors for 25(OH)D levels <25 nmol/L included being ≤8.5 years old (OR 4.95, 95% CI: 1.92–12.74), having PTH ≥7 pmol/L (OR 2.28, 95% CI: 1.17–4.46), being female (OR 2.44, 95% CI: 1.22–4.88), and being overweight or obese (OR 2.18, 95% CI: 1.11–4.26).

Conclusions

The results show relatively low levels of 25(OH)D in young schoolchildren in Kuwait, with lower levels in girls. Given the association of 25(OH)D with a wide range of ailments, it is necessary to further examine the causes and risk factors of low vitamin D in this age group to prevent associated health problems.

     

Serum 25 Hydroxy Vitamin D Insufficiency Associated with Bronchial Asthma in Lucknow,India

Objectives

To assess the association between serum 25 hydroxy vitamin D levels and asthma and its control in Indian children.

Methods

This was a prospective case–control study conducted in tertiary care hospital. Cases of asthma and healthy age-matched controls were included, aged 1–15 y, who had not received any vitamin D supplementation in the last year and had no other co-morbidity, after obtaining written informed parental consent. 25 hydroxy vitamin D insufficiency was taken below level of ≤ 30 ng/mL.

Results

Fifty asthmatics and 25 age-matched controls were recruited from August 2011–July 2012. 25 hydroxy vitamin D insufficiency was associated with occurrence of asthma (OR?=?13.5; 95 % CI?=?4.25–42.85: p?=?0.000). With decreasing level of asthma control there was increasing strength of association with 25 hydroxy vitamin D insufficiency [χ ² for trend?=?24.96 (p?=?0.000)].

Conclusions

25 hydroxy vitamin D insufficiency is associated with bronchial asthma as well as its level of control.     

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.     

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 diabetic Egyptian children and adolescents: a case–control study

Background

Recently, studies suggesting that vitamin D deficiency correlates with the severity and frequency of Type 1 (insulin-dependent) diabetes mellitus (T1DM) and that vitamin D supplementation reduces the risk of developing T1DM have been reported.

Objective

In this study, we aimed to assess vitamin D status in Egyptian children and adolescents with T1DM.

Methods

This was a case–control study including 80 T1DM diagnosed cases aged 6 to 16 years and 40 healthy children with comparable age and gender as the control group. For all subjects, serum 25 (OH) D levels were measured by ELISA, Serum parathyroid hormone (PTH) and serum insulin were measured by an electrochemiluminesce immunoassay. Serum glucose, Glycosylated hemoglobin (HbA1c) levels and homeostasis model assessment of insulin resistance (HOMA-IR) were also assessed.

Results

Compared to the control group, serum vitamin D levels were not significantly lower in diabetic subjects (24.7?±?5.6 vs 26.5?±?4.8 ng/ml; P?>?0.05). Among diabetic cases 44(55%) were vitamin D deficient; meanwhile 36(45%) cases had normal vitamin D level (P?<?0.01). In addition, 26(32.5%) diabetic cases had 2ry hyperparathyroidism and 54(67.5%) cases had normal parathyroid hormone level; meanwhile, none of the control group had 2ry hyperparathyroidism (P?<?0.01). Furthermore, we found a significant difference between vitamin D deficient diabetic cases and those with normal vitamin D level as regards HOMA-IR and diabetes duration (P?<?0.01).

Conclusion

Public health message on the importance of vitamin D status; especially in diabetic children and adolescents, should be disseminated to the public.

     

Vitamin D fortification of growing up milk prevents decrease of serum 25-hydroxyvitamin D concentrations during winter: a clinical intervention study in Germany

Vitamin D plays an important role in human health. Current recommendations for vitamin D intake and endogenous supply through sun exposure are not met in German pre-school children, and suboptimal serum 25-hydroxyvitamin D concentrations, especially during the winter months, are common. Consequently, vitamin D supplementation or fortification have gained increased acceptance. The KiMi trial (Kindermilch?=?growing up milk) was a prospective, randomized, and double-blind study in which young children (2–6 years of age, n?=?92) were assigned to receive either vitamin D-fortified growing up milk (2.85 μg/100 ml) or semi skimmed cow's milk without added vitamin D. Daily consumption of fortified growing up milk contributed to the prevention of an otherwise frequently observed decrease in serum 25-hydroxyvitamin D concentration during winter (before winter: median 21.5 ng/mL (10.1–43.0 ng/mL) intervention vs. median 18.4 ng/mL (11.0–44.9 ng/mL) control; after winter: median 24.8 ng/mL (7.0–48.2 ng/mL) intervention vs. median 13.6 ng/mL (7.0–36.8 ng/mL) control) and proved to be safe during summer (median 27.6 ng/mL (18.8–40.5 ng/mL) intervention vs. median 27.4 ng/mL (17.8–38.7 ng/mL) control). Due to the high prevalence of vitamin D deficiency, fortification of growing up milk with vitamin D at a level used in this study could be an effective measure to improve vitamin D status.     

Vitamin D,Low-Grade Inflammation and Cardiovascular Risk in Young Children: A Pilot Study

Vitamin D has anti-inflammatory properties, and deficiency is prevalent in children. There is a paucity of data regarding vitamin D status and its correlation with low-grade inflammation and vasculature. We prospectively enrolled 25 children, 9–11 years old (13 male); 21 obese. Eight atherosclerosis-promoting risk factors were scored as categorical variables with the following thresholds defining abnormality: body mass index Z score ≥1.5; systolic blood pressure ≥95th percentile (for age, sex, and height); triglyceride ≥100 mg/dL; low-density lipoprotein cholesterol (LDL-C) ≥110 mg/dL; high-density lipoprotein cholesterol ≤45 mg/dL; hemoglobin A1C (HBA1C) ≥5.5; 25-hydroxyvitamin D [25(OH) D] ≤30 ng/mL, and tobacco smoke exposure. High-sensitivity C-reactive protein (hsCRP) was measured to assess low-grade inflammation and classified as low- (<1 mg/L), average- (1–3 mg/L), and high-risk (>3 to <10 mg/L) groups. The proportion of children within each hsCRP group who had above threshold risk factors was calculated. Carotid artery ultrasound was performed to measure carotid artery intima-media  thickness (CIMT). Median (range) for 25(OH) D was 24 (17–45) ng/mL. Eighteen were either 25 (OH) D deficient (<20 ng/mL) or insufficient (20–30 ng/mL), and seven were sufficient (>30 ng/mL). hsCRP was 1.7 (0.2–9.1) mg/L, with 11 being <1.0 mg/L, 8 between 1.0–3.0 and 6 > 3.0 to < 10.0 mg/L. Risk factor score was 3.9 ± 1.7 out of eight. 25(OH) D levels did not correlate with hsCRP or CIMT. While vitamin D deficiency, inflammation, and risk factors coexist at a very young age, causative mechanisms remain unclear.     

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 and acute lower respiratory infection in early childhood in Sylhet,Bangladesh

Aim: Acute lower respiratory tract infection (ALRI) is the most important global cause of childhood death. Micronutrient deficiencies may increase the risk of ALRI. A case–control study was conducted to assess the association between vitamin D status and ALRI in rural Bangladesh. Methods: Children aged 1–18 months hospitalized with ALRI (cases) were individually matched to controls on age, sex, and village (N = 25 pairs). The mean serum 25‐hydroxyvitamin D concentration [25(OH)D] in cases and controls was compared using paired t‐test. The unadjusted and adjusted odds of ALRI were assessed by multivariate conditional logistic regression. Results: Mean [25(OH)D] was significantly lower among ALRI cases than controls (29.1 nmol/L vs. 39.1 nmol/L; p = 0.015). The unadjusted odds of ALRI was halved for each 10 nmol/L increase in [25(OH)D] (OR 0.53, 95% CI 0.30–0.96). Adjustment for confounders increased the magnitude of the association. Conclusion: Vitamin D status was associated with early childhood ALRI in a matched case–control study in rural Bangladesh. Randomized trials may establish whether interventions to improve vitamin D status can reduce the burden of ALRI in early childhood.     

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.     

Prevalence of vitamin D insufficiency among healthy school-age Cree children

BACKGROUND:

First Nations children are at higher risk for vitamin D deficiency and rickets.

OBJECTIVE:

To assess the prevalence of vitamin D deficiency and the correlations between fat mass, parathyroid hormone and dietary habits with serum vitamin D level in a random sample of Cree children eight to 14 years of age.

METHODS:

Serum 25-hydroxyvitamin D (25[OH]D) levels and additional information regarding anthropometrics and dietary habits were obtained from participants in two Cree communities. Vitamin D deficiency and insufficiency was defined as serum 25(OH)D levels <30 nmol/L and <50 nmol/L, respectively. Proportions to estimate the vitamin D status were weighted to account for the complex sampling design, and Pearson’s correlation coefficients were used to estimate the associations of milk and fish intake, parathyroid hormone and fat mass with serum 25(OH)D levels.

RESULTS:

Data from 52 healthy Cree children (mean [± SD] age 11.1±2.0 years; 27 boys) were included in the analyses. The median serum 25(OH)D level was 52.4 nmol/L (range 22.1 nmol/L to 102.7 nmol/L). Forty-three percent (95% CI 29% to 58%) and 81% (95% CI 70% to 92%) of Cree children had vitamin D levels <50 nmol/L and <75 nmol/L, respectively. Vitamin D intake was positively associated with serum 25(OH)D levels. Obese children had lower vitamin D levels; however, the difference was nonsignificant.

CONCLUSION:

There may be a substantial proportion of Cree children who are vitamin D deficient. Increasing age, lower dietary vitamin D intake and, possibly, higher body mass index were associated with decreased vitamin D levels; however, causality cannot be inferred.     

Vitamin D concentrations among healthy children in Calgary, Alberta

OBJECTIVE:

To examine the relationship between serum vitamin D concentrations, dietary intake and body mass index among healthy children living in Calgary, Alberta.

METHODS:

The present cross-sectional study included healthy children two to 13 years of age who presented to the Alberta Children’s Hospital for elective surgery during a 12-month period. Data including the child’s weight, height, age, sex, ethnicity, dietary intake, use of vitamin supplements, physical activity and time spent outdoors were collected. Serum concentrations of 25-hydroxyvitamin D (25[OH]D) were measured using commercial immunoradiometric assay kits.

RESULTS:

Serum 25(OH)D concentrations were available for 1442 of 1862 participants, of whom 862 (59.8%) were boys. The mean (± SD) serum 25(OH)D concentration was 86.1±35.1 nmol/L (range 10 nmol/L to 323 nmol/L). Five hundred thirty-nine (37.4%) participants had insufficient vitamin D status (25[OH]D between 25 nmol/L and lower than 75 nmol/L), and vitamin D deficiency (25[OH]D 25 nmol/L or lower) was present in 29 subjects (2.0%). Children in the older age group (nine to 13 years) were more likely to have suboptimal vitamin D (P<0.001). Other risk factors significantly associated with suboptimal vitamin D status included overweight or obesity, nonwhite ethnicity, winter months, dietary vitamin D intake of less than 200 IU/day and less time spent outdoors.

CONCLUSION:

A high rate of suboptimal vitamin D concentrations was observed among the participants. Beyond promoting a vitamin D-enriched diet, physicians should also consider the body mass index and other risk factors to determine the optimal vitamin D intake for children living in the area studied.     

VITAMIN D METABOLISM IN PRETERM INFANTS

ABSTRACT. In order to evaluate after birth the changes in circulating vitamin D metabolite levels in preterm babies supplemented with vitamin D (2100 I. U./d), the serum concentration of 25-hydroxyvitamin D [25-OHD] and 1 α,25-dihydroxy vitamin D [1, 25(OH)₂D] were measured in 22 infants (31 to 35 weeks of gestation) from birth up to 96 hours of age. Compared to cord blood levels, serum calcium decreased significantly during the first 24 hours of life ( p <0.005) and remained low until day 4. Serum immunoreactive parathyroid hormone (iPTH) levels increased from birth to 24 hours and then plateaued. The 25-OHD levels at birth were 27.5±2.5 nmol/l and increased to 67.5±12.5 nmol/l ( p <0.005) during the four days of the study. During the same period, the 1, 25(OH)₂D serum levels increased steadily from 84<7 to 343<105 pmol/l ( p <0.005). At all times, there was a positive correlation between 25-OHD levels and those of 1, 25(OH)₂D. Our data demonstrate that in preterm infants after 31 weeks of gestation, absorption and activation of vitamin D is present as soon as 24 hours after birth and that early neonatal hypocalcemia is unlikely to be caused by an impairment of either PTH secretion or vitamin D activation.     

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.