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.     

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.     

Severe acute hypercalcemia in a child caused by accidental vitamin D poisoning

The authors report a case of acute severe hypercalcemia (5.20 mmol/l) in a 9-month-old boy. Vitamin D poisoning is confirmed by high serum level of 25 OHD (287 mcg/l; N = 10-60) while the source of intoxication is unknown. Individual idiopathic vitamin D hypersensitivity is eliminated because of a negative diagnosis test. Management with prednisone, high intravenous fluid saline intake, furosemide and calcitonin results in a favourable outcome. Vitamin D intoxication has always to be evoked when acute severe hypercalcemia occurs in infants.     

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.     

Severe hypercalcemia of an infant due to vitamin D toxicity associated with hypercholesterolemia

We report an 11 month-old infant with severe hypercalcemia associated with hyperlipidemia following bolus vitamin D administration. At the time of admission, serum concentration of calcium was 5.5 mmol/l (22 mg/dl); total cholesterol, high density lipoprotein cholesterol (HDL-C), very low density lipoprotein (VLDL), low density lipoprotein cholesterol (LDL-C), and triglyceride levels were respectively: 6.37 mmol/l (246 mg/dl), 0.77 mmol/l (30 mg/dl), 1.37 mmol/l (54 mg/dl), 4.1 mmol/l (162 mg/dl), 3 mmol/l (271 mg/dl). Physical examination revealed dehydration and irritability that was inappropriately mild according to the serum calcium level. On the 16th day of therapy that consisted of intravenous fluids with furosemide (sodium diuresis), steroid, calcitonin, magnesium sulfate, and phosphorus, serum calcium level declined below 3 mmol/l (12 mg/dl). The hyperlipidemia resolved gradually with a concomitant decline in serum calcium. This report is interesting in that hypercalcemia was associated with transient hyperlipidemia that disappeared with normocalcemia, which might suggest protection against hypercalcemic symptoms.     

Comparison between daily supplementation doses of 200 versus 400 IU of vitamin D in infants

The daily supplementation of vitamin D is mandatory for infants. However, there are still conflicting opinions about the exact daily dose. Thus, we aimed to evaluate a daily supplementation dose of 200 IU is sufficient and compared the supplementation doses of 200 and 400 IU per day. One hundred and sixty-nine infants were randomly assigned to two groups (group1, 200 IU/day; group 2, 400 IU/day) and there were 75 infants in group 1 and 64 were in group 2 with a total number of 139. The median levels of 25-hydroxyvitamin D3 were significantly increased in group 2 at the age of 4 months (group 1, 39.60 mcg/L; group 2, 56.55 mcg/L; p?<?0.0001). We clearly demonstrated that at the age of 4 months, none of the infants on the group 2 had a serum level of 25-hydroxyvitamin D3 less than 30 mcg/L. However, 21.3 % of the infants in group 1 had a level below 30 mcg/L. Thus, in order to avoid vitamin D deficiency and rickets, we recommend supplementation dose of vitamin D at 400 IU/day as a safe and effective dose.     

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.     

Low serum 25-hydroxyvitamin D levels and bronchiolitis severity in Spanish infants

This cross-sectional study was performed to examine the prevalence of hypovitaminosis D in infants with acute bronchiolitis compared with control subjects and to evaluate the relationship between serum 25-hydroxyvitamin D (25(OH) D) and the severity of bronchiolitis. Serum 25(OH) D levels were measured by radioimmunoassay in 48 infants with acute bronchiolitis (2.5?±?2.0 months) and in 30 healthy infants (3.2?±?2.3 months). 25(OH) D levels (ng/ml) in children with acute bronchiolitis were significantly lower than in the control group (median 29.9 ng/ml (interquartile range (IQR) 21.4–37.5) versus median 38.2 ng/ml ((IQR 26.1–48.1), p?=?0.022), mainly in infants with moderate–severe bronchiolitis (median 29.8 ng/ml, IQR 19.2–35.9). The prevalence of hypovitaminosis D was remarkably greater among infants with bronchiolitis than in control subjects (52.1 versus 26.6 %). A significant inverse correlation was found between serum 25-hydroxyvitamin D levels and disease severity (rho?=??0.457, p?<?0.001). Conclusion: The prevalence of hypovitaminosis D is high in Spanish infants with bronchiolitis. The severity of acute bronchiolitis increases with a decline in serum 25 (OH) D level.     

Severe hypercalcemia due to vitamin D intoxication]

We report on a case of severe hypercalcemia due to vitamin D intoxication in a 4-month-old infant, CASE REPORT: A 4-month-old boy was admitted for anorexia, weakness, hypotonia, constipation and lethargy. Initial physical examination evidenced a severe axial hypotonia, signs of moderate intracellular dehydration, polyuria and leucocyturia. Hemodynamic parameters were normal. The infant's origin was Turkish. Basic blood chemistry showed a high serum calcium concentration of 4.28 and 4.55 mmol/l on a second control. The EKG showed a short QTc interval calculated at 0.34 s. Due to worsening neurological condition, the infant was referred to the pediatric intensive care unit. Because of the association of neurological impairment, EKG abnormality and high serum calcium level, haemodialysis was performed. Treatment included hyperhydration, high doses of intravenous of loop diuretics and sodium pamidronate infusion. Hormonal, radiological, abdominal and cardiac investigations combined with a new parental interview led to the diagnosis of vitamin D intoxication due to excessive daily administration. We were unable to determine the exact total amount because of the language barrier. Clinical outcome was marked by nephrocalcinosis without renal function impairment, iliac venous thrombosis secondary to the dialysis catheter and a full neurological recovery without sequelae after 3 months. DISCUSSION: Fear of rickets, especially in Turkish families residing in France, can lead some parents to administer massive daily quantities of vitamin D. This practice is facilitated by the possibility of purchasing high dosage forms of vitamin D via the Internet. When faced with an infant presenting with digestive disorders such as vomiting and constipation, associated with neurological troubles (lethargy, hypotonia) and hypercalcemia, vitamin D intoxication should be considered after tumoral, hormonal or malformative (Williams-Beuren syndrome) causes have been eliminated. Combined with hyperhydration and loop diuretics, biphosphonate infusion often allows to control hypercalcemia. Nephrocalcinosis seems correlated to chronic administration while cardiovascular disorders are more likely associated with massive acute vitamin D administration, severe dysrhythmia being rare in children in this context.     

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.     

The Association Between Vitamin D Status and Recurrent Wheezing

Objective

To investigate association between vitamin D status and recurrent wheezing in infants.

Methods

Thirty infants with recurrent wheezing and 45 healthy, similar aged infants without any history of acute or chronic illness were included in the study. The clinical features of infants were recorded and serum 25-hydroxyvitamin D [25(OH)D] levels were measured. Data analysis was performed using SPSS 13 package program.

Results

The mean value of 25 (OH) D vitamin levels were 22.1?±?8.9 IU/L and 18.8?±?11 IU/L for the control and recurrent attack group respectively. Seventy-three percent of subjects with recurrent wheezing had vitamin D levels in the deficient range (<20 ng/ml) and 48.9 % had vitamin D levels under?<?20 ng/ml in the control group. The percentage of insufficient vitamin D levels (<30 ng/ml) were 90 and 77.8 for the patient and control group respectively. Eight patients had extremely deficient vitamin D (<10 ng/ml) levels. There was no statistical significance between the groups in terms of the distribution of 25 (OH)D level.

Conclusions

The present study did not demonstrate significant association between vitamin D status and recurrent wheezing in the infants.     

注意缺陷多动障碍患儿血清25羟基维生素D水平的检测

目的 了解注意缺陷多动障碍(ADHD)患儿维生素D的营养状况,探讨维生素D与ADHD的关系。方法 选取2014年 1月至2015年 1月符合美国精神障碍诊断与统计手册第五版(DSM-V)中ADHD诊断、分型标准的97例ADHD患儿为病例组,其中注意缺陷为主型(ADHD-I型)46例,多动冲动为主型(ADHD-HI型)10例,混合型(ADHD-C型)41例,以同期同年龄行健康体检儿童97例作为对照组。采用电化学发光法对ADHD组和对照组儿童血清中25羟基维生素D[25(OH)D]水平进行检测,比较两组儿童25(OH)D水平的差异。结果 ADHD组患儿血清25(OH)D水平(17±7 ng/mL)明显低于对照组(23±8 ng/mL)(P< 0.01);且各亚型ADHD患儿25(OH)D水平均明显低于对照组(P< 0.05)。ADHD组患儿25(OH)D水平正常、不足及缺乏的比例分布情况与对照组比较差异有统计学意义(P< 0.01);且各亚型ADHD患儿25(OH)D水平的分布情况与对照组比较差异均有统计学意义(P< 0.05)。结论 ADHD患儿25(OH)D水平明显低于健康儿童,25(OH)D水平与ADHD可能存在一定的相关性。     

Effect of Vitamin D Supplementation on Moderate to Severe Bronchial Asthma

Objective

To define the therapeutic role of vitamin D in children with moderate to severe bronchial asthma as an adjunct to standard treatment.

Methods

Hundred asthmatic children of either sex, attending the respiratory and asthma clinic were enroled in the study. Diagnosis was made on the basis of history and clinical examination. Randomization was done using sealed opaque envelop method. In addition to the treatment as per GINA guidelines, one group received oral vitamin D3 (Cholecalciferol) 60,000 IU per month for 6 mo and the other group received placebo powder in the form of glucose sachet with a double blinded design. Monthly follow up of every patient was done and during every visit change in severity, level of control, Peak expiratory flow rate (PEFR), steroid dosage, number of exacerbations and number of emergency visits were assessed.

Results

Monthly doses of 60,000 IU vitamin D significantly reduced the number of exacerbations as compared to placebo (p?=?0.011). PEFR significantly increased in the treatment group (p?=?0.000). Monthly doses of vitamin D significantly reduced the requirement of steroids (p?=?0.013) and emergency visits (p?=?0.015). Control of asthma was achieved earlier in patients who received monthly vitamin D. Vitamin D significantly reduced the level of severity of asthma patients over 6 mo of treatment (p?=?0.016).

Conclusions

Vitamin D has a definite role in the management of moderate to severe persistent bronchial asthma as an adjunct to standard treatment.     

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 NUTRITIONAL STATUS OF PREMATURE INFANTS SUPPLEMENTED WITH 500 IU VITAMIN D2 PER DAY

ABSTRACT. The vitamin D nutritional status of premature infants was assessed by determining plasma 25-hydroxyvitamin D concentrations before and during supplementation with 500 IU vitamin D₂ per day. Fifty-one samples were collected from 25 healthy infants fed breast milk and a vitamin D₃ fortified formula. Gestational age was 32.2±2.4 weeks (mean ± 1 SD). 25-hydroxyvitamin D levels before supplementation correlated well with maternal values ( r =0.81). The infants' mean plasma concentration increased from 30.6±13.7 nmol/l (mean±1 SD) after birth to 46.3±10.5 nmol/l after 9±1 days ( p <0.0025), and to 65.3±16.6 nmol/l after 37±10 days of vitamin D₂ treatment ( p <0.0005). 25-hydroxyvitamin D₂ and 25-hydroxyvitamin D₃ were determined separately, and it appeared that the rise was accounted for by the D₂ fraction while 25-hydroxyvitamin D₃ concentrations were unchanged. The results demonstrate that vitamin D₂ is well absorbed and hydroxylated in the 25 position by premature infants free of associated disease, and that a supplementation of 500 IU per day in addition to breast milk and a regular vitamin D fortified formula is adequate to rapidly establish 25-hydroxyvitamin D levels within the normal adult range.     

Vitamin D-dependent rickets type I and type II

Two distinct hereditary defects, vitamin D-dependent rickets type I (VDDR I) and type II (VDDR II), have been recognized in vitamin D metabolism. VDDR I is suggested to be a deficiency of the renal 25-hydroxyvitamin D (25(OH)D)-1α-hydroxylase. Muscle weakness and rickets are the prominent clinical findings. A normal physiologic dose of 1α-hydroxyvitamin D₃ and 1,25-dihydroxyvitamin D₃ is sufficient to maintain remission of rickets in this disorder. VDDR II consists of a spectrum of intracellular vitamin D receptor (VDR) defects and is characterized by the early onset of severe rickets and associated alopecia. This can be attributed to mutations in the VDR gene. Massive doses of vitamin D analogs and calcium supplementation is usually required for the treatment; however, the response to therapy is sometimes variable.     

Relation between biomarkers and clinical severity in patients with Smith–Lemli–Opitz syndrome

Smith–Lemli–Opitz syndrome (SLOS), a multiple congenital anomaly with severe mental retardation, is caused by decreased activity of 7-dehydrocholesterol reductase. Fifteen Hungarian patients were diagnosed with SLOS on the basis of clinical symptoms, serum cholesterol, 7-dehydrocholesterol, and molecular genetic testing. Their age at the time of diagnosis in mild SLOS (n?=?4, clinical score <20) was 0.5–18 years, cholesterol was 2.37?±?0.8 mmol/L, and 7DHC was 0.38?±?0.14 mmol/L. In the group of typical SLOS (n?=?7, score 20–50), the diagnosis was set up earlier (age of 0.1–7 years); t-cholesterol was 1.47?±?0.7 mmol/L, and 7DHC was 0.53?±?0.20 mmol/L. Patients with severe SLOS (n?=?4, clinical score?>?50) died as newborns and had the lowest t-cholesterol (0.66?±?0.27 mmol/L), and 7DHC was 0.47?±?0.14 mmol/L. Correlation coefficient with clinical severity was 0.74 for initial t-cholesterol and 0.669 for Cho/7DHC. Statistically significant difference was between the initial t-cholesterol of mild and severe SLOS (p?=?0.01), and between the Cho/7DHC ratios of groups (p?=?0.004). In severe SLOS, the percentage of α-lipoprotein was significantly lower than in typical (p?=?0.003) and mild SLOS (p?=?0.004). Although serum albumin, total bilirubin, and hemostasis parameters remained in the reference range during cholesterol supplementation (n?=?10) combined with statin therapy (n?=?9), increase of aspartate aminotransferase and alanine aminotransferase in 50 % of the patients probably refers to a reversible alteration of liver function; therefore, statin therapy was suspended. Conclusion: life expectancy is fundamentally determined by the initial t-cholesterol, but dehydrocholesterol and α-lipoprotein have prognostic value. Accumulation of hepatotoxic DHC may inhibit the synthesis of α-lipoproteins, decreasing the reverse cholesterol transport. During statin therapy, we suggest monitoring of lipid parameters and liver function.     

Hypercalcemia in children receiving pharmacologic doses of vitamin D

Vitamin D deficiency causes rickets, requiring vitamin D at doses greater than daily dietary intake. Several treatment regimens are found in the literature, with wide dosing ranges, inconsistent monitoring schedules, and lack of age-specific guidelines. We describe 3 children, ages 2 weeks to 2 and 9/12 years, who recently presented to our institution with hypercalcemia and hypervitaminosis D (25-hydroxyvitamin D levels >75 ng/mL), associated with treatment of documented or suspected vitamin D-deficient rickets. The doses of vitamin D used were within accepted guidelines and believed to be safe. The patients required between 6 weeks and 6 months to correct the elevated serum calcium, with time to resolution of hypercalcemia related to age and peak serum calcium, but not to peak 25-hydroxyvitamin D level. With recent widespread use of vitamin D in larger dosages in the general population, we provide evidence that care must be taken when using pharmacologic dosing in small children. With limited dosing guidelines available on a per weight basis, the administration of dosages to infants that are often used in older children and adults has toxic potential, requiring a cautious approach in dose selection and careful follow-up. Dosage recommendations may need to be reassessed, in particular, where follow-up and monitoring may be compromised.     

Idiopathic infantile hypercalcemia discovered in the newborn period

We report a male newborn with typical clinical signs of idiopathic infantile hypercalcemia (IIH); that is, hypercalcemia, hypercalciuria, an elfin face and nephrocalcinosis without giving Vitamin D₃ supplementation to the patient. He had been treated with a vitamin D-free, low calcium milk and rectal administration of exogenous calcitonin (elcatonin). The latter seemed to be more effective as a treatment for IIH. The serum calcium level came within the normal range and the serum 1,25-dihydroxyvitamin D₃ (1,25[OH]₂D₃) level decreased from 101.5 to 75.6 pg/mL with the treatments mentioned above. These results suggest that a high serum concentration of 1,25(OH)₂D₃ is part of the pathogenesis of IIH. However, we were not able to clarify the pathogenesis of the high serum concentration of 1,25(OH)₂D₃.