High prevalence of vitamin D deficiency in school-age children in Tehran, 2008: a red alert. Public Health Nutr. 2012;15:324-330. [PMID: 21356149 DOI: 10.1017/s1368980011000188]

Serum Biomarker Analysis in Pediatric ADHD: Implications of Homocysteine, Vitamin B12, Vitamin D, Ferritin, and Iron Levels

The current diagnosis of attention deficit hyperactivity disorder (ADHD) is based on history, clinical observation, and behavioral tests. There is a high demand to find biomarkers for the diagnosis of ADHD. The aim of this study is to analyze the serum profiles of several biomarkers, including homocysteine (Hcy), vitamin B12, vitamin D, ferritin, and iron, in a cohort of 133 male subjects (6.5-12.5 years), including 67 individuals with an ADHD diagnosis based on DSM-V criteria and 66 age-matched healthy boys (healthy controls, HC). Assessments for ADHD included the Iowa Conners' Teacher Rating Scale (CPRS) and the ADHDT test, as well as cognitive assessments using the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the TROG-2 language comprehension test. Hcy and iron were quantified using spectrophotometry, while vitamin B12 and total 25-hydroxy vitamin D levels were determined using an electrochemiluminescence immunoassay (ECLIA) and ferritin was measured using a particle-enhanced immunoturbidimetric assay. The results showed significantly increased Hcy levels and decreased vitamin B12 levels in ADHD patients compared to HCs. Multiple logistic regression analysis indicated that Hcy is a potential prognostic indicator for ADHD. These results suggest that elevated homocysteine and decreased vitamin B12 may serve as markers for the diagnosis and prognosis of ADHD.

Metabolic and Genetic Association of Vitamin D with Calcium Signaling and Insulin Resistance

Various evidences have unveiled the significance of Vitamin D in diverse processes which include its action in prevention of immune dysfunction, cancer and cardiometabolic disorders. Studies have confirmed the function of VD in controlling the expression of approximately nine hundred genes including gene expression of insulin. VD insufficiency may be linked with the pathogenesis of diseases that are associated with insulin resistance (IR) including diabetes as well as obesity. Thus, VD lowers IR-related disorders such as inflammation and oxidative stress. This review provides an insight regarding the molecular mechanism manifesting, how insufficiency of VD may be connected with the IR and diabetes. It also discusses the effect of VD in maintaining the Ca2+ levels in beta cells of the pancreas and in the tissues that are responsive to insulin.

Neurological Symptoms That May Represent a Warning in Terms of Diagnosis and Treatment in a Group of Children and Adolescents with Vitamin D Deficiency

AIM

This research was intended to evaluate the clinical and laboratory findings of children presenting to our pediatric neurology clinic with symptoms potentially linked to vitamin D deficiency and with low vitamin D levels and the distribution of those findings by sex, age groups, and vitamin D levels.

METHODS

This retrospective study involved patients presenting to our clinic with symptoms potentially associated with vitamin D deficiency and low serum concentrations of 25 OH vitamin D (25 OH D) (<75 nmol/L, 30 µg/mL). Patients' movement disorders and central nervous system-related symptoms at the time of presentation and serum 25 OH D, calcium (Ca), phosphorus (P), and magnesium (Mg) levels were recorded and evaluated in terms of age, sex, and vitamin D levels.

RESULTS

Eight hundred twenty-two cases of vitamin D deficiency were included in the study, 50.2% (n = 413) boys and 49.8% (n = 409) girls. Although cases of vitamin D deficiency were present across all the age groups between 1 and 18, they were most common in the 5-14 age range (n = 372, 45.3%). Movement disorders were observed in 14.6% (n = 120) of our cases, and neurological findings associated with the central nervous system were observed in 52.6% (n = 432). The most common accompanying movement in our cases was difficulty remaining in balance (n = 42, 35%), while the most frequent accompanying central nervous system finding was vertigo (n = 99, 22.92%). Other movement disorders encountered included limb shaking (n = 32, 26.7%), abnormal posture (n = 20, 16.67%), easy falling (n = 16, 13.33%), body rigidity (n = 15, 12.5%), and hand clenching (n = 5, 4.17%). Other frequently encountered neurological findings were headache (n = 88, 20.37%), epileptic seizures (n = 83, 19.21%), fainting (n = 58, 13.43%), developmental delay (n = 41, 9.49%), febrile seizures (n = 33, 7.64%), and numbness in the fingers (n = 20, 4.63%). Other neurological findings were sleep disorders (n = 10, 2.31%), nightmares (n = 8, 1.85%), pain in the extremities (n = 7, 1.62%), and sweating and frailty (n = 4, 0.93% for both). Ca, P, and Mg levels were lower in cases with vitamin D levels < 12 µg/mL. The prevalences of both movement disorders and central nervous system findings varied according to age groups, sex, and vitamin D levels.

CONCLUSIONS

Our study results show that vitamin D deficiency can present with different neurological findings and that these may vary according to age group, sex, and vitamin D levels. Clinicians must take particular care in pediatric cases with neurological findings in terms of the early diagnosis and treatment of vitamin D deficiency.

Relationship of Vitamin D Deficiency with Cervical Vertebral Maturation and Dental Age in Adolescents: A Cross-Sectional Study

Background

Considering the high prevalence of vitamin D deficiency and its effect on growth and development, the assessment of the dental age and skeletal age with regard to vitamin D deficiency status could influence the treatment planning of growth modification treatment. This study aimed to assess the relationship between vitamin D deficiency, cervical vertebral maturation (CVM) as an indicator of skeletal age, and dental age in adolescent patients.

Methods

In this cross-sectional study, the chronological age of 52 orthodontic patients aged between 10 and 14 years was recorded, and their serum level of vitamin D was determined using a radioimmunoassay test. The patients were then divided into three groups based on their serum vitamin D level: severe deficiency, moderate deficiency, and the control group with normal vitamin D. The panoramic radiographs of patients were assessed to determine their dental age using Demirjian's method. CVM was determined on lateral cephalograms using Baccetti's classification to specify the skeletal age. Data were analyzed using a t-test, linear regression, ordinal logistic regression, and Pearson's correlation coefficient (at P < 0.05, confidence interval = 95%).

Results

Skeletal age showed a significant difference between the group with severe vitamin D deficiency and the control group (P=0.01); however, such difference was not observed between the group with moderate vitamin D deficiency and the control group (P=0.12). Dental age was not significantly different between the groups with vitamin D deficiency and the control group (P=0.26 for severe, and P=0.39 for moderate deficiency).

Conclusions

A less advanced skeletal maturation was observed in adolescents with severe vitamin D deficiency; however, dental development was not affected by this deficiency. Vitamin D status is better to be considered in decision-making for the initiation of growth modification orthodontic treatments.

Deficiency of Daily Calcium and Vitamin D in Primary School Children in Lviv, Ukraine

This study was conducted to determine the prevalence of calcium and vitamin D deficiency in school children aged 6 to 11 years in Lviv (Ukraine). The aim of this study was also to assess the effect of nutritional intervention and supplementation on serum calcium and vitamin D levels in children diagnosed with calcium deficiency. A 3 day diet was analyzed in 172 children. In 56 children with a deficiency of calcium and/or vitamin D, the level of total calcium, ionized calcium, and 25-hydroxyvitamin D in blood, as well as the calcium content in hair samples, was determined. Thirty children with confirmed calcium and/or vitamin D deficiency underwent a dietary intervention to increase calcium and vitamin D intake for 3 months. The study group (n = 15) was provided with a nutritional correction by modifying their diet with supplementation of calcium and vitamin D. The control group (n = 15) received only a diet modification. Decreased daily calcium intake was observed in 50.68% of boys and 70.71% of girls. A decreased level of daily vitamin D consumption was found in 84.93% of boys and 96.97% of girls. Among 56 children with insufficient daily consumption of calcium and/or vitamin D, 26.8% had reduced levels of total calcium in the blood, 16.1% had reduced levels of ionized calcium in the blood, and 48.2% had reduced levels of vitamin D. After 3 months of correction, normal calcium level was found in the hair of 10 students (66.7%) from the study group and in three subjects (20.0%) from the control group. Modification of the diet along with supplementation of calcium and vitamin D seems to be a more effective method for increasing the level of calcium among children aged 6 to 11 years.

How Much Does Serum 25(OH)D Improve by Vitamin D Supplement and Fortified Food in Children? A Systematic Review and Meta-Analysis

OBJECTIVES

This study was conducted to respond certain important questions regarding the efficacy of vitamin D fortification and supplementation in children using a meta-analytical approach.

METHODS

MEDLINE, PubMed, Embase, Cochrane Library, and Google Scholar were searched, and 2341 studies were found in a preliminary search. After screening of titles and abstracts, 31 studies were selected.

RESULTS

Significant raises in circulating 25-hydroxy vitamin D (25(OH)D) concentrations were observed in both groups that took vitamin D supplement (mean difference [MD] 28.7, 95% confidence interval [CI] 22.5-34.9) and vitamin D-fortified foods (MD 20.29, 95% CI 13.3-27.2). The meta-regression revealed a significant association between age of participants (B -1.4, 95% CI -2.8, -0.02, P = 0.047) and dose of vitamin D (B 0.007, 95% CI 0.003, 0.01, P < 0.001), with the effect on serum 25(OH)D concentrations. The analysis showed that serum 25(OH)D concentration increases by 0.7 nmol/L for every 100 IU of vitamin D intake after adjustment for age, baseline serum 25(OH)D and latitude which is far less than the reported amount in adults.

CONCLUSIONS

Altogether, these findings indicate that in a mass vitamin D fortification program, circulating 25(OH)D concentration response in children may be lower in children than in adults and vitamin D supplementation may still be needed in this subpopulation.

Association of serum 25-hydroxyvitamin D concentration with anthropometric measures in children and adolescents: the CASPIAN-V study

BACKGROUND

Serum 25-hydroxyvitamin D (25(OH)D) concentrations reflect vitamin D status, with deficiency implicated as an underlying factor for many adverse health effects. This study aims to analyze the association between vitamin D status and different anthropometric measures in a large pediatric population.

METHODS

This nationwide cross-sectional study was conducted in 2019 in blood samples obtained from school students of 30 provinces in Iran. Participants were 2596 children and adolescents aged 7-18 years. Weight, height, waist circumference (WC), hip circumference (HC), neck circumference (NC), and wrist circumference (WrC) were measured. Body mass index (BMI) and waist-to-height ratio (W/HtR) were calculated. Serum 25(OH)D concentrations were measured using chemiluminescent immunoassay.

RESULTS

Participants consisted of 55% boys, 71.3% urban inhabitants, with a mean (SD) age of 12.1 (3.0) years. Overall, vitamin D deficiency was documented in 10.6% of participants, insufficiency in 60.4%, and sufficiency in 29% of the population studied. The mean of BMI and WC was higher in the vitamin D deficient than in the vitamin D sufficient group (19.31 kg/m² and 69.24 cm vs. 18.34 kg/m² and 65.73 cm, respectively, P < 0.01). Multivariate linear regression models revealed a significant association of vitamin D insufficiency with WC and W/HtR (P < 0.05). Likewise, in the multivariate regression models, vitamin D deficiency was associated with BMI, WC, and W/HtR (P < 0.05).

CONCLUSION

Our findings on the inverse association between vitamin D status and some anthropometric measures underscore the importance of providing vitamin D by fortification and supplementation programs of vitamin D for the pediatric population.

LEVEL OF EVIDENCE

V.

Independent and Combined Effects of Calcium and Vitamin D Supplementation on Blood Lipids in Overweight or Obese Premenopausal Women: A Triple-Blind Randomized Controlled Clinical Trial

Background:

Dyslipidemia is often associated with obesity and contributes to the increased risk of atherosclerosis, heart disease, and stroke. This study was designed to evaluate the independent or combined effect of calcium and vitamin D (Ca + Vit D) supplementation on blood lipid profile in overweight or obese premenopausal women.

Methods:

This study is a triple-blind, randomized, parallel, placebo-controlled trial. About 100 overweight or obese (body mass index (BMI) of 25–40 kg/m²) premenopausal (aged 30–50 years) women, recruited from Shiraz University of Medical Sciences (SUMS) clinics, were allocated into 4 groups: (1) calcium (Ca) supplementation (2 tablets per day; each containing 500 mg calcium carbonate), (2) vitamin D (Vit D) supplementation (2 tablets per day; each containing 200 IU vitamin D3), (3) Ca + Vit D supplementation (2 tablets per day; each containing 500 mg calcium carbonate plus 200 IU vitamin D3), (4) placebo supplementation (2 tablets per day, containing micro-cellulose). All participants received a 500 kcal energy-restricted diet. Blood lipids, serum vitamin D, and anthropometric indices were measured at baseline and after 8 weeks. Physical activity and 3-day dietary records were taken at baseline and every 4 weeks during the intervention.

Results:

At 8 weeks, triglyceride levels were significantly decreased in the Ca group (P = 0.002). Low-density lipoprotein (LDL) levels were decreased in the Ca + Vit D group (P = 0.04) and high-density lipoprotein (HDL) levels decreased in both the Ca and Ca + Vit D groups (P = 0.006, P = 0.004, respectively). The results of one-way ANOVA indicated that changes in the serum lipid profile levels were not significantly different among the four groups (P = 0.90, P = 0.86, P = 0.61, P = 0.27, and P = 0.19, respectively for TG, TC, LDL, HDL, and LDL/HDL). The results were not significant even after adjusting for potential covariates.

Conclusions:

Although the results were not significantly different among the four treated groups at 8 weeks, within-group changes like the reduction in triglyceride and LDL levels, respectively in the Ca group and Ca + Vit D group, and HDL levels in both the Ca and Ca + Vit D groups were significant. These changes may have potentially significant public health implications.

Vitamin D Deficiency in Children and Adolescents: Role of Puberty and Obesity on Vitamin D Status

Background:

Vitamin D deficiency is common among children and adolescents and can be affected by several factors such as puberty and obesity.

Objective:

The aim of this study was to evaluate vitamin D status in children and adolescents and to analyse the influence of puberty and obesity on its level.

Method:

A cross-sectional study was carried-out, in which clinical and biochemical data were gathered from 384 healthy children and adolescents between May 2019 to May 2020.

Results:

220 females and 164 males were enrolled (aged 7-16 years; mean ± SD: 11 ± 2.5). Vitamin D deficiency was found in 49% of the total cases and was significantly more prevalent in females than males (33.1% in female; 15.9% in male, P < .001). Mean vitamin D level was lower in obese children compared with non-obese (P < .001). Non-obese group had significantly higher levels of vitamin D in Tanner stage IV of puberty than obese individuals (20.1 ± 17.0 vs 5.4 ± 2.0) (P = .03). Vitamin D levels were significantly lower in females than males only in Tanner stage II (12.3 ± 9.0 vs 19.6 ± 16.6) (P = .005). The lowest level of Vitamin D was in Tanner stage Ⅳ-Ⅴ in boys and in Tanner stage Ⅱ-Ⅲ in girls (P < .001).

Conclusion:

Puberty is an additional risk factor for vitamin D deficiency especially in girls and obese children. This increased risk, together with the fact that most important time for building a proper skeleton is during childhood and adolescent, makes it essential to monitor vitamin D in these age groups.

Metagenomic analysis of the gut microbiome composition associated with vitamin D supplementation in Taiwanese infants

Early childhood is a critical stage for the foundation and development of the gut microbiome, large amounts of essential nutrients are required such as vitamin D. Vitamin D plays an important role in regulating calcium homeostasis, and deficiency can impair bone mineralization. In addition, most people know that breastfeeding is advocated to be the best thing for a newborn; however, exclusively breastfeeding infants are not easily able to absorb an adequate amount of vitamin D from breast milk. Understanding the effects of vitamin D supplementation on gut microbiome can improve the knowledge of infant health and development. A total of 62 fecal sample from healthy infants were collected in Taiwan. Of the 62 infants, 31 were exclusively breastfed infants and 31 were mixed- or formula-fed infants. For each feeding type, one subgroup of infants received 400 IU of vitamin D per day, and the remaining infants received a placebo. In total, there are 15 breastfed and 20 formula-fed infants with additional vitamin D supplementation, and 16 breastfed and 11 formula-fed infants belong to control group, respectively. We performed a comparative metagenomic analysis to investigate the distribution and diversity of infant gut microbiota among different types of feeding regimes with and without vitamin D supplementation. Our results reveal that the characteristics of infant gut microbiota not only depend on the feeding types but also on nutrients intake, and demonstrated that the vitamin D plays an important role in modulating the infant gut microbiota, especially increase the proportion of probiotics in breast-fed infants.

The association of serum levels of zinc and vitamin D with wasting among Iranian pre-school children

PURPOSE

Wasting is a main indicator of Child's undernutrition that is associated with several non-communicable diseases and child mortality. This is the first population-based study which evaluated the association of serum zinc and vitamin D levels with wasting in a Middle East region. We also reported the prevalence of vitamin D and zinc deficiencies among Iranian pre-school children aged 6 years.

METHODS

This was a multicenter cross-sectional study that included 425 children aged between 5 and 7 years (on average 6 years) with BMI-for-age Z-scores of < - 1 SD resident in urban and rural areas of Iran in the spring of 2012 as part of the National Integrated Micronutrient Survey 2 (NIMS-2). Anthropometric measurements and blood sampling were obtained. The prevalence of vitamin D and zinc deficiencies together with the correlations of these variables with the increase of BMI-for-age Z-scores were evaluated.

RESULTS

The prevalence of vitamin D and zinc deficiencies was 18.8% and 12.7%, respectively. In addition, 31.1% of children were wasted. Children in the second tertile of 25(OH)D levels were less likely to have wasting compared with those in the first tertile in both crude and adjusted models (OR 0.47, 95% CI 0.27-0.83). A significant inverse association was found between serum levels of zinc and wasting (OR 0.57, 95% CI 0.34-0.96); such that after adjusting for confounders, children in the highest tertile of serum zinc had 47% less odds of wasting compared with those in the first tertile (OR 0.53, 95% CI 0.31-0.91).

CONCLUSION

The prevalence of vitamin D and zinc deficiencies among Iranian pre-school children aged 6 years was 18.8 and 12.7%, respectively. Serum levels of vitamin D and zinc were inversely associated with wasting either before or after controlling for confounders.

LEVEL OF EVIDENCE

Level III, case-control analytic studies.

Association between variants in vitamin D-binding protein gene and vitamin D deficiency among pregnant women in china

BACKGROUND

The prevalence of vitamin D deficiency and insufficiency is extremely high in pregnant women worldwide. However, the association between single nucleotide polymorphisms (SNPs) in vitamin D metabolic pathway genes and 25-hydroxyvitamin D (25(OH)D) concentration among Chinese pregnant women is seldom reported. The risk of adverse neonatal outcomes due to maternal vitamin D deficiency has not been well investigated.

METHODS

A total of 815 pregnant women and 407 infants were enrolled in this study. Serum 25(OH)D concentration was detected. DNA was extracted from the maternal blood for genotyping genetic SNPs in vitamin D pathway. An XGBoost model was established based on SNPs combined with external variables.

RESULTS

Mean serum 25(OH)D level was 15.67 ± 7.98 ng/mL among the pregnant women. Seventy-five percent of pregnant women had 25(OH)D deficiency in China. SNPs of GC (rs17467825, rs4588, rs2282679, rs2298850, and rs1155563) were significantly associated with maternal 25(OH)D concentration. The influence of variants of rs17467825, rs4588, rs2282679, and rs2298850 on maternal 25(OH)D might be modified by vitamin D supplementation and sunshine exposure. An XGBoost model was established for monitoring 25(OH)D status in pregnant women and provided clinical advice to reduce the risk of 25(OH)D deficiency. Mothers with 25(OH)D deficiency hinted a risk for macrosomia.

CONCLUSION

A high prevalence of vitamin D deficiency in China has been confirmed. A clinical model was established to guide pregnant women to supplement vitamin D according to genotype. Furthermore, we suggest the effect of maternal vitamin D status on the risk of macrosomia.

Modulating effect of vitamin D status on serum anti-adenovirus 36 antibody amount in children with obesity: National Food and Nutrition Surveillance

Background

The association of ADV-36 infection and obesity has been reported in children.

The objective of this study was to examine the hypothesis that the association between ADV-36 infection and adiposity may be mediated by sub-optimal vitamin D status of the host.

Methods

Ninety one apparently healthy children in different weight categories (normal weight: 33, overweight: 33, obesity: 25) aged 5–18 years were randomly selected from the registered population at National Food and Nutrition Surveillance Program (NFNS). The groups were matched based on age and sex. Anthropometric, biochemical and serological assessments were performed.

Results

The amount of anti-ADV36-Ab increased whereas circulating concentrations of 25(OH) D decreased across BMI categories with higher amounts in children with normal weight than in children with overweight and obesity (31.0 ± 16.4, 22.5 ± 10.5 and 21.9 ± 9.8 nmol/L, respectively, p = 0.004). Logistic regression analysis revealed that for each unit increment of anti-ADV36-Ab, the chance of increase in weight was 8.5 times (OR: 8.5, p = 0.029). Interestingly, when 25(OH) D was introduced into the model, anti-ADV36-Ab was no longer the predictor of weight increment and the chance of increase in weight reduced 5% for each unit increase in 25(OH) D concentration (OR: 0.95, p = 0.012).

Conclusion

It is suggested that ADV36-induced lipogenesis may be mediated by vitamin D deficiency in children with obesity.

Vitamin D deficiency in school-age Iranian children with attention-deficit/hyperactivity disorder (ADHD) symptoms: A critical comparison with healthy controls

The associations between serum vitamin D levels and the severity of attention-deficit/hyperactivity disorder (ADHD) symptoms were assessed among Iranian hospitalized children (50 ADHD cases and 50 healthy (non-ADHD) controls) during 2014-2015. Levels of ADHD severity and serum 25-hydroxyvitamin D (25OHD) were determined by the Conners' Parent Rating Scale (CPRS) test and an ELISA kit, respectively. The serum 25OHD concentrations of <10, 10-29, and >30 ng/mL were respectively considered as deficient (severe deficiency), insufficient (mild deficiency), and sufficient levels of vitamin D. The association of nutrient bioavailability with ADHD was evaluated by statistical and regression analyses.There was no significant difference in the mean of socio-demographic variables (e.g., gender, age, weight, BMI, daily intake of dairy products, and daily sunlight exposure) between ADHD and non-ADHD subjects. The mean serum 25OHD concentration (16.57 ± 9.09 ng/mL) was found to be significantly lower in ADHD children with more parathyroid hormone (PTH) levels as compared to controls (22.01 ± 12.67ng/mL). The sufficient 25OHD concentration was more predominant in the controls than the cases (p = 0.002). A severe deficiency of vitamin D was more found in children with ADHD (3.36 times). There was a negative and significant association between the participants' age and their serum 25OHD levels. Although 25OHD levels in boys were significantly more than those in girls, the reduction of serum 25OHD concentration among boys with ADHD was more severe compared to the patient girls(p = 0.014). The results support the importance of vitamins D role in ADHD patients through the regular monitoring of serum 25OHD levels.

Efficacy of Vitamin D Supplementation in Physical Performance of Iranian Elite Athletes

Background:

There has been no report of the vitamin D status of the professional athletes from Iran to date. This study was performed to evaluate the efficacy of weekly vitamin D supplementation on athletic performance in Iranian athletes expedited to Asian competition in Taipei, China, 2015.

Methods:

This study was a randomized controlled clinical trial. Seventy subjects were enrolled in the study. The athletes were randomly divided into two groups: vitamin D supplement (D; received 50,000 IU of vitamin D supplement weekly) and control (P, received a placebo weekly). Duration of the study was 8 weeks. Anthropometric, dietary, athletic performance, and biochemical evaluations were performed for all subjects in the beginning and in the end of the intervention period.

Results:

A significant rise in circulating 25(OH)D concentration was observed in D group (17.3 ± 16.9 ng/mL, P < 0.001), whereas in P group, there was a statistically significant decrement (−3.1 ± 8.4 ng/mL, P = 0.040). There were no either within- or between-group significant differences in Ergo jump, vertical jump, and agility tests. In strength leg press tests, both groups showed a significant improvement. However, comparisons of changes revealed that the improvement in D group was significantly higher than in P group (P = 0.034). Moreover, in sprint test (one repetition-Max, 1RM), only D group had a significant within-group improvement (P = 0.030).

Conclusions:

Weekly supplementation with 50,000 IU vitamin D resulted in nearly 17 ng/mL increment in circulating calcidiol. This increase was associated with significant improvement of power leg press and sprint tests in D-supplemented group.

Association of Vitamin D Status and Metabolic Syndrome Components in Iranian Children

Background:

Recently, it has been found that Vitamin D can affect cardiometabolic risk factors. However, these findings have not been confirmed in younger population. We aimed to assess the associations of serum 25-hydroxyvitamin D (25(OH)D) and metabolic syndrome (MetS) components in Iranian children.

Methods:

This cross-sectional study was conducted on 240 children aged 6–9 years old. Anthropometric indices (weight, height, waist circumference, and body fat), biochemical parameters (low-density lipoprotein, high-density lipoprotein, triglyceride [TG], fasting blood sugar, and serum 25(OH)D), systolic blood pressure (SBP) and diastolic blood pressure (DBP) blood pressure, and dietary intake and physical activity were measured. Multivariate linear regression analysis was used to assess the association of MetS components and serum 25(OH)D.

Results:

Mean age of children was 7.8 ± 1.06 year. Mean serum 25(OH)D concentration was 14.6 ± 10.64 ng/ml, and the prevalence of Vitamin D deficiency (serum 25(OH)D lower than 10 ng/ml) was 41.66%. Dietary intake of Vitamin D was 1.91 ± 1.8 mcg/day. Serum 25(OH)D was inversely associated with TG (β = −0.16; CI: −0.27, −0.04) after adjusting by age, gender, body mass index, physical activity, and some dietary components. Serum 25(OH)D was negatively associated with SBP (β = −0.02; CI: (−0.05, −0.004), and DBP (β = −0.02; CI: −0.05, −0.003); however, it was not significant anymore after adjustment for sodium, potassium, and fiber.

Conclusions:

Vitamin D deficiency is alarming among Iranian children. Among the components of MetS, lower serum Vitamin D concentration was only associated with TG that could contribute in onset and progression of cardiometabolic disorders later in life.

Effect of vitamin D treatment in children with attention-deficit hyperactivity disorder

BACKGROUND

In this research the symptom improvement of attention-deficit hyperactivity disorder (ADHD) of children was assessed by oral vitamin D administration in Tabriz, Iran.

METHODS

In this double-blind, randomized clinical trials, 96 children (2-18 years) were enrolled to placebo and vitamin D groups. Children took vitamin D pearl (50,000 IU/week) or placebo for 6 weeks. Children, who had the change in methylphenidate dosage and received any anticonvulsants and corticosteroids were excluded from the research. ADHD symptoms were diagnosed by Conners parent rating scale (CPRS) test at baseline and after intervention. ADHD Conners divided into inattention (IA), hyperactivity/impulsivity (H/I) and combination type (C) subscales. Vitamin D serum level was assessed at baseline and after 8 weeks in both groups.

RESULTS

The differences between CPRS and its subscales were not significant at baseline (P > 0.05). The Conners IA score was decreased in vitamin D group (P < 0.05; adjusted with age and baseline values). ADHD Conners and all subscale scores reduced remarkably after intervention in patients with insufficient level of vitamin D compared to placebo (P < 0.05).

CONCLUSIONS

Oral vitamin D improved ADHD symptoms with a particular effect on inattention symptoms. In addition, symptoms related to all subscales were improved remarkably in patients with insufficient level of vitamin D. Vitamin D treatment in children with ADHD could be considered due to the expand benefit of vitamin D in body.

Prevalence of vitamin D deficiency in Iran: A systematic review and meta-analysis

BACKGROUND

The prevalence of vitamin D deficiency in the Iranian community is very high. Women and older people are at the higher risk of vitamin D deficiency.

AIM

This study aimed to estimate the prevalence of vitamin D deficiency in Iran by combining the results of various studies.

METHODS

This was a systematic review and meta-analysis. Separate strategies were developed for search in national databases (Irandoc, Magiran, SID) and international databases (Web of Science, PubMed, and Scopus) using the keywords of "vitamin D deficiency," "Iran," and "prevalence." The titles and abstracts of the articles were screened and related full texts were appraised. Those articles that met inclusion criteria were selected for meta-analysis. The heterogeneity of the articles was assessed via the Chi-square test. They were combined using the random-effect approach. In addition, the groups were categorized and analyzed in terms of age and gender.

RESULTS

Of 639 articles, 30 articles with a sample size of 26,042 people were included for data analysis. The overall prevalence of vitamin D deficiency was reported as 0.56. Subgroup analysis showed that 0.64 of women and 0.44 of men were suffering from vitamin D deficiency. The prevalence of vitamin D deficiency in the age groups under 20, 20-50, and over 50 years was 0.56.4, 0.72.4, and 0.59.8, respectively.

CONCLUSIONS

The Iranian Ministry of Health is expected to design strategies to improve the status of vitamin D at the national level.

High prevalence of vitamin D deficiency in pregnant women and its relationship with adverse pregnancy outcomes in Guizhou, China

OBJECTIVE

This study was performed to investigate the prevalence of vitamin D deficiency in pregnant women in Guizhou, China and its correlation with adverse infant and maternal outcomes during the perinatal period.

METHODS

In total, 220 pregnant women who received perinatal care and delivered in the Affiliated Hospital of Guizhou Medical University from November 2014 to April 2015 were enrolled. Each woman's serum vitamin D concentration was tested during early pregnancy, and its correlation with adverse infant and maternal outcomes in the perinatal period was analyzed.

RESULTS

The mean serum vitamin D concentration was 29.5 ± 5.8 nmol/L. More than 90% of pregnant women had vitamin D insufficiency. Additionally, 38.4% of women with vitamin D deficiency and 22.2% with vitamin D inadequacy developed adverse perinatal outcomes. The vitamin D level was negatively correlated with adverse pregnancy outcomes.

CONCLUSION

Vitamin D deficiency is highly prevalent among pregnant women in Guizhou, China. The incidence of adverse perinatal outcomes was far higher in association with vitamin D deficiency than sufficiency. A negative correlation was found between the vitamin D level and the incidence of adverse perinatal outcomes in pregnant women. Therefore, targeted screening and proper supplementation are needed during early pregnancy.

Effect of vitamin D supplementation on serum 25-hydroxyvitamin D concentration in children and adolescents: a systematic review and meta-analysis protocol

INTRODUCTION

The importance of vitamin D for bone health as well as its role in non-skeletal functions has long been documented. However, review investigations on the effect of vitamin D supplementation on serum 25-hydroxyvitamin D (25(OH)D) levels in children and adolescents are scarce. The aims of the current study were to assess the impact of various doses of vitamin D supplementation on serum 25(OH)D concentrations in children and adolescents, and to identify relevant determinants of variations in the effect of vitamin D supplementation.

METHODS

PubMed, Scopus, ISI Web of Science and Cochrane Central Register of Controlled Trials databases up to 27 September 2017 will systematically be searched for randomised controlled trials of vitamin D supplementation. We considered articles with the following control groups as eligible: placebo control, control group without any supplementation or a comparative arm investigation. Two reviewers will assess articles for eligibility according to prespecified selection criteria, after which data extraction and quality appraisal will be conducted by two independent reviewers. The quality assessment will be assessed using the Jadad scale. Meta-analyses will be conducted where appropriate. We will express continuous measures (ie, serum 25(OH)D concentration) as mean differences with 95% CIs. Heterogeneity of the data will be investigated via visual inspection of the forest plots and using χ² test on N-1 df, with a significance level of α=0.1. We will also assess individual study and subgroup characteristics and perform a sensitivity analysis. Publication bias will be assessed using funnel plot and statistical analysis of Egger's test.

ETHICS AND DISSEMINATION

Ethics approval is not required because the work will be carried out on published documents. The authors will publish findings from this review through peer-reviewed publication or conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42017067179.

Prevalence of vitamin D deficiency in healthy Iranian children: A systematic review and meta-analysis

Background: Vitamin D deficiency is related to rickets in children, and it can increase the risk of osteoporosis in adulthood. The aim of our study was to estimate the prevalence of vitamin D deficiency among healthy Iranian children and adolescents. Vitamin D levels less than 20ng/ml and between 20 and 30ng/ml was considered as vitamin D deficiency and insufficiency, respectively. Methods: Relevant observational studies evaluating the prevalence of vitamin D deficiency through 1 January 1990 to 28 Dec 2016, were searched in several electronic databases including Iran-Medex, Scientific Information Database (SID), Irandoc, PubMed and NLM Gateway (for MEDLINE), Web of Science, and Scopus with no restriction on language. Only full-text articles were used for data extraction and synthesis after considering the inclusion/exclusion criteria. Results: 11 studies included; the data of four studies of Iranian newborns were withdrawn because of their high heterogeneity. The prevalence of vitamin D deficiency in Iranian boys and girls were 35% (CI 95% 34-37) and 61% (CI 95% 60-63), respectively. The prevalence of vitamin D insufficiency in Iranian children and adolescents was 31% (CI 95% 30-31). Conclusion: It seems that the prevalence of vitamin D deficiency is very high among Iranian children and adolescents. The present findings could provide practical information for healthcare decision makers.

Lifestyle factors and multiple sclerosis: A population-based incident case-control study

OBJECTIVE

Although low sun exposure, low vitamin D, and smoking are established risk factor of multiple sclerosis (MS), there is less evidence on the role of the other lifestyle factors. We examined the association of sun exposure, physical activity, drug abuse, and alcohol intake with MS.

MATERIALS AND METHODS

This was population-based incident case-control study in Iran with 547 incident cases and 1057 general population controls (7/8/2013-17/2/2015). Logistic regression was used to analyse the data.

RESULTS

Higher sun exposure during adolescence was associated with a reduced risk of MS, both in summer (test for trend p < 0.001) and winter (P < 0.001), while physical activity was not associated with MS (test for trend p = 0.712). Lifetime drug abuse (OR for ever use 2.93 (1.83-4.70)), with a dose-response association (test for trend p < 0.001), and alcohol intake (OR for ever use 1.49 (1.05-2.12)) was significantly associated with an increased risk of MS.

CONCLUSION

In a middle-eastern setting, we found that sun exposure during adolescence, drug abuse, and alcohol use were all associated with MS. Increasing sun exposure and reducing drug abuse and the use of alcohol through educational programs is likely to reduce the rate of MS.

Healthy changes in some cardiometabolic risk factors accompany the higher summertime serum 25-hydroxyvitamin D concentrations in Iranian children: National Food and Nutrition Surveillance

OBJECTIVE

To investigate seasonal variations of vitamin D status at different latitudes and if these changes are accompanied by corresponding variations in certain health parameters in children living in a broad latitudinal range in Iran.

DESIGN

Longitudinal study.

SUBJECTS

In total, 530 apparently healthy children aged 5-18 years were randomly selected from six regions of Iran with a latitudinal gradient from 29°N to 37·5°N. All anthropometric and biochemical assessments were performed twice during a year (summer, winter). High BMI (Z-score >1), low HDL cholesterol (150 mg/dl) were considered cardiometabolic risk factors.

RESULTS

Serum 25-hydroxyvitamin D (25(OH)D) showed between-season variation, with significantly higher concentrations (mean (sd)) in summer v. winter (43 (29) v. 27 (18) nmol/l; P33°N v. <33°N: 4·5; 0·09, 9·0; P=0·04) were predictors of change of serum 25(OH)D between two seasons.

CONCLUSIONS

Summertime improvement of vitamin D status was accompanied by certain improved cardiometabolic risk factors, notably serum TAG, total cholesterol and BMI, in children.

Association of Serum 25-hydroxyvitamin D Levels and Liver Enzymes in a Nationally Representative Sample of Iranian Adolescents: The Childhood and Adolescence Surveillance and Prevention of Adult Noncommunicable Disease Study

Background:

Hypovitaminosis D is highly prevalent and has several adverse health effects. This study aims to assess the relationship of serum concentrations of 25-hydroxyvitamin D (25[OH] D) and liver enzymes in adolescents.

Methods:

This population-based cross-sectional survey was conducted among a nationally representative multistage sample of 1095 adolescents (52% boys), aged 10–18 years, living in different provinces of Iran. Serum 25(OH)D concentration <30 ng/mL was considered as hypovitaminosis D, and liver enzymes (alanine aminotransaminase [ALT] and aspartate aminotransaminase [AST]) of >40 U/L was considered as high level. To determine the association between serum 25(OH)D categories and elevated levels of liver enzymes, multiple regression models and linear regression analysis were applied, after adjustment for potential confounders. Odds ratios (95% confidence interval) of serum 25(OH)D and elevated liver enzymes were assessed by logistic regression analysis.

Results:

Higher rates of Vitamin D deficiency were documented among individuals with increased levels of liver enzymes. Compared to boys, median of 25(OH)D was lower in girls with elevated levels of liver function tests (12.75 vs. 25.60 ng/mL for ALT and 13 vs. 14.10 ng/mL for AST), with marginally significant gender differences regarding AST.

Conclusions:

We found a relatively high frequency of hypovitaminosis D among adolescents with abnormal liver function. Further prospective studies are needed to examine these associations from early life.

Current Evidence on Vitamin D Deficiency and Metabolic Syndrome in Obese Children: What Does the Evidence from Saudi Arabia Tell Us?

Obesity and vitamin D deficiency represent major health problems among Saudi children, and have been linked to chronic diseases. Obese children are at risk of developing vitamin D deficiency, which appears to have negative influences on energy homeostasis, impeded bone mineralisation, insulin resistance and inflammation. Evidence supporting the association between vitamin D deficiency of obese children and metabolic syndrome has not specifically been studied in early childhood. The mechanisms through which vitamin D deficiency is associated with metabolic syndrome in obese children needs further elucidation. This commentary aims to (i) summarise current knowledge of the association between vitamin D deficiency and metabolic syndrome in obese children; and (ii) discuss current evidence for the association among Saudi Arabian children.

Association between serum concentration of 25-hydroxyvitamin D and community-acquired pneumonia: a case-control study

Background

Community-acquired pneumonia (CAP) is a common disease with significant morbidity and mortality. There is evidence that vitamin D deficiency can be associated with infectious diseases. The aim of this study was to compare the levels of vitamin D between patients with CAP and healthy controls.

Methods

In a case-control study on 73 patients with CAP and 76 healthy controls, the serum concentration of 25-hydroxyvitamin D (25[OH]D) was measured. Severity and outcomes of disease and also duration of hospital stay were compared in patients with different levels of 25(OH)D. The severity of CAP was assessed using the CURB-65 score (confusion, uremia, respiratory rate, low blood pressure, age ≥65 years) and was also reflected by the length of hospital stay, admission to intensive care unit (ICU), and 30-day mortality.

Results

In total, 81.2% of the study population had vitamin D levels <30 ng/dL. The risk of pneumonia among subjects with deficient vitamin D levels was 3.69 (95% CI: 1.46, 9.31) times of those with sufficient vitamin D level (P=0.006). Prevalence of severe deficiency of vitamin D in scores three and four of CURB-65 (59.38%), was far more than scores one and two (31.71%). Also, results indicated patients with severe deficiency had a higher risk for ICU admission, 30-day mortality, and longer hospitalization stay, but these were not statistically significant.

Conclusion

According to findings, a low level of 25(OH)D is associated with a higher incidence of CAP and more severe disease. It is recommended to pay more attention to vitamin D deficiency in infectious diseases, particularly in CAP patients.

Vitamin D status and cardiometabolic risk factors across latitudinal gradient in Iranian adults: National food and nutrition surveillance

BACKGROUND

This study aimed to evaluate the vitamin D status in an adult population across latitudinal gradient and to investigate its possible associations with certain cardiometabolic risk factors.

METHODS

A total of 1406 healthy subjects aged 19-60 years were randomly selected from six regions of Iran across latitudinal gradient from 29° N to 37.5° N. Anthropometric and biochemical assessments were performed. The combination of high body mass index (>25 kg/m²), low high-density lipoprotein cholesterol (< 40 mg/dl in males and < 50 mg/dl in females) and high triglycerides (> 150 mg/dl) was defined as cardiometabolic risk factors.

RESULTS

The mean concentration of serum 25-hydroxycalciferol (25(OH)D) was 26.8±17.7 nmol/l. There were no significant differences in the mean serum 25(OH)D levels among different latitudes. Undesirable vitamin D status (deficiency and insufficiency) was found in 90.7% of the subjects. After adjustment for age and gender, the association between weight status and serum 25(OH)D was significant ( p< 0.04, odds ratio:1.49; confidence interval: 1.01-2.19). The prevalence of cardiometabolic risk factors among the subjects with serum 25(OH)D less than 27.5 nmol/l was significantly higher than those with serum calcidiol concentrations above 27.5 nmol/l (13.3% vs. 10.0%, p = 0.033).

CONCLUSION

Undesirable vitamin D status is highly prevalent among Iranian adults of both sexes irrespective of latitude and even in sunny regions. The occurrence of cardiometabolic risk factors was significantly higher in those subjects with circulating calcidiol concentrations below 27.5 nmol/l.

Impact of fortified biscuits on micronutrient deficiencies among primary school children in Bangladesh

BACKGROUND

Micronutrient deficiencies can compromise the development potential of school-aged children, and their later health and productivity as adults. School feeding and school-based fortification approaches have been utilized globally to redress nutritional deficiencies in this age group.

OBJECTIVE

We explored the acceptability and micronutrient impact of a Bangladesh Government supported school-based micronutrient fortification program for children attending rural primary schools in 10 disadvantaged sub-districts.

METHODS

We applied a mixed methods approach. The quantitative component assessed the impact of micronutrient fortification on 351 children aged 6-11 years using a cohort pre-post research design with a control group. The qualitative component explored the acceptability of the intervention using focus group discussions, body mapping and semi-structured interviews with teachers, school-going children and school authorities.

RESULTS

Daily consumption of fortified biscuits by primary school children had a significant positive impact on mean levels of iron, folic acid, vitamin B12, retinol and vitamin D controlling for sex, baseline deficiency status, CRP, and H. pylori. Levels of anemia and vitamin D deficiency were also significantly reduced. Qualitative findings indicated the widespread acceptability of the daily biscuit. Teachers perceived students to be more attentive in class, less tired, and some attributed better school performance to biscuit consumption. Children reported similar improvements in concentration and energy levels.

CONCLUSIONS

This study is among the first in Bangladesh to comprehensively assess a school-based fortification program in terms of its acceptability and impact on micronutrient status of children aged 6-11 years of age. While results strongly support this modality of school feeding, research on the cognitive impacts of micronutrient fortified biscuits will help clarify the case for scaled-up investments in school- based feeding program in Bangladesh and other low and middle income countries.

Vitamin D deficiency/insufficiency from childhood to adulthood: Insights from a sunny country

Vitamin D is known to be a key regulator of bone metabolism and is associated with muscle strength. Vitamin D deficiency is widely prevalent worldwide. In adults, vitamin D deficiency has been implicated in numerous health conditions including osteoporosis, cancer, diabetes, and autoimmune diseases. Considerable changes have occurred in lifestyles and childhood activities in the past years. Studies have shown that the children population is at high risks of vitamin D deficiency. The objective of this study was to learn about the extent of vitamin D deficiency in children worldwide and especially in sunny country like Israel. In this article we reviewed the extent and severity of vitamin D deficiency worldwide and especially in Israel, through a very comprehensive review of previous reports and research studies done during the last years. We found reports on vitamin D deficiency in children, which was associated with metabolic syndromes and obesity. It was more prevalent in children who spend less time on outdoor activities, in obese children, and in cases when there was imbalance between nutritional intakes and requirements. Vitamin D deficiency is common even in children living in sunny places like Israel. Health professionals should be aware of the fact that although vitamin D deficiency is prevalent in the elderly population, it is also common in children, and can be associated with different illnesses. We encourage supplementation of vitamin D to special populations (pregnant and lactating women, infants, and high risk groups). We also encourage implementation of international food fortification programs.

Vitamin D Status, Latitude and their Associations with Some Health Parameters in Children: National Food and Nutrition Surveillance

BACKGROUND

Recent data indicate a role for vitamin D in many health aspects including anthropometric measures and blood lipid profiles. Dermal vitamin D synthesis may be influenced by latitude. However, the contribution of latitude in vitamin D status and its association with anthropometric and blood lipid measures in Iranian children have not been studied to date.

METHODS

We used data from the National Food and Nutritional Surveillance Program. In total, 667 apparently healthy children aged 5-18 years were randomly selected from six provinces of Iran with different latitudes, from 29 to 37°. Weight, height, circulating 25-hydroxycalciferol; calcidiol [25(OH)D] and blood lipids were measured.

RESULTS

In total, 16.7 and 4.1% of children were overweight or obese, respectively. The mean 25(OH)D concentration was 27.3 ± 17.6 nmol/l (95% confidence interval: 26.0-28.7 nmol/l). Over 93% of all children had suboptimal circulating calcidiol concentrations. Undesirable status of vitamin D, serum triglyceride and low-density lipoprotein were all more prevalent in children living in regions  >33° latitude than those in  <33°, significantly. There was no significant difference in duration of sun exposure between children living in latitudes below and above 33° (p = 0.093). In multivariate regression model, sex, latitude, body mass index for age z-score and sun exposure duration were independently related to 25(OH)D concentrations, but age was not.

CONCLUSION

Despite significant association of latitude and vitamin D status, hypovitaminosis D is prevalent across latitude gradient in Iranian children. Our findings warrant immediate sustainable nutritional intervention, including supplementation, to protect children from hypovitaminosis D irrespective of the latitude of their residence.

Effect of vitamin D supplementation as adjunctive therapy to methylphenidate on ADHD symptoms: A randomized, double blind, placebo-controlled trial

OBJECTIVES

Previous studies have shown that serum levels of vitamin D were lower in attention deficit hyperactivity disorder (ADHD) children compared to healthy controls. The aim of the study was to determine the effect of vitamin D supplementation as adjunctive therapy to methylphenidate on symptoms of children with ADHD.

METHODS

Sixty-two children aged 5-12 years with a diagnosis of ADHD based on DSM-IV criteria were randomly assigned into two groups to receive either 2000IU vitamin D or placebo in addition to methylphenidate for 8 weeks. Symptoms severity was assessed by Conner's Parent Rating Scale-Revised[S] (CPRS), ADHD rating scale-IV (ADHD-RS), and Weekly Parent Ratings of Evening and Morning Behavior (WPREMB) at weeks 0, 4, and 8. Serum levels of 25(OH)D were measured at baseline and after 8 weeks. Anthropometric variables, dietary intake, physical activity, sun exposure, and side effects were assessed.

RESULTS

Fifty-four participants completed the trial. After 8 weeks of supplementation, serum levels of 25(OH)D significantly increased in the vitamin D group. ADHD symptoms decreased significantly in both groups (P < 0.05). Evening symptoms and total score of WPREMB scale were significantly different at weeks 4 and 8 between the two groups (P = 0.013, 0.016, respectively), but no differences were found in symptoms by CPRS and ADHD-RS scales.

DISCUSSION

Vitamin D supplementation as adjunctive therapy to methylphenidate improved ADHD evening symptoms. Future research is needed to clarify vitamin D effects as monotherapy in ADHD and its mechanism. The trial was registered in www.irct.ir is (IRCT201404222394N10).

Vitamin D supplementation during pregnancy on infant anthropometric measurements and bone mass of mother-infant pairs: A randomized placebo clinical trial

INTRODUCTION

Based on the essential role of vitamin D in the regulation of calcium metabolism, we evaluated the effects of 2000IUvitamin D/day in late pregnancy on infant's anthropometric measurements and bone mass parameters of mother-infant pairs.

MATERIAL AND METHODS

In this randomized clinical trial, the main inclusion criteria were: aged 18 or older, no history of internal diseases and pregnancy complications, and a singleton live fetus. The intervention group received two 1000IU vitamin D₃ pills (2000IU) daily from weeks 26-28 until childbirth. Maternal serum 25-hydroxyvitamin D, infants' anthropometric measurements (at birth, 4th and 8th weeks postnatal), and maternal and infant bone mass parameters were examined.

RESULTS

The two groups were not statistically different in relation to baseline 25-hydroxyvitamin D concentrations. However, there was a significant difference between the study groups with regard to change in vitamin D status over time (p<0.001). In cross-sectional analysis, the two groups were not different with respect to anthropometric measurements in three time points. Also, in repeated measure analysis, the two groups did not show any statistical differences concerning the infants' anthropometric measurements. The bone mass measurements of all the 28 mothers who belonged to the two study groups were not different. Finally, the bones mass measurements of the infants in the two study groups were not different.

CONCLUSION

Ingestion of 2000IUvitamin D₃/day during late pregnancy did not improve anthropometric measurements of infants from birth until the 8th week postnatal, nor improve the maternal and infant bone mass measurements.

Assessment of Vitamin D Status and Response to Vitamin D3 in Obese and Non-Obese Iranian Children

BACKGROUND

Obesity seems to be a critical issue nowadays because of its high prevalence and its adverse effects on health. There is some evidence indicating the relationship between obesity and lower serum 25-hydroxyvitamin D [25(OH)D] concentration. The aim of the present study was to examine serum 25(OH)D status of obese and non-obese Iranian children and compare their therapeutic response with identical oral vitamin D3 treatment.

METHODS

In a non-randomized clinical trial, serum 25(OH)D level of 45 obese and 45 non-obese Iranian children aged 2-14 years was measured. Those with serum 25(OH)D status <30 ng/ml (73 cases) were treated with one pearl of vitamin D3 (50 000 International Units) once a week for 6 weeks. Serum vitamin D was measured once more 2 weeks after treatment.

RESULTS

The frequency of hypovitaminosis D was 43/45 (95.6%) in obese and 30/45 (66.7%) in non-obese children at baseline (p < 0.001). After treatment of 73 cases (43 obese, 30 non-obese), the above percentages were decreased to 24/43 (55.8%) and 1/30 (3.3%), respectively (p < 0.001).

CONCLUSION

Our study demonstrated a high frequency of vitamin D deficiency among Iranian children, particularly the obese ones. Moreover, low therapeutic response in the obese group is witnessed.

The effect of a single dose of vitamin D on glycemic status and C-reactive protein levels in type 2 diabetic patients with ischemic heart disease: a randomized clinical trial

AIMS

To assess whether a single parental dose of 25-hydroxy vitamin D [25(OH)Vit D] could improve glucose control and inflammation in type 2 diabetic patients (T2D) with ischemic heart disease (IHD).

METHODS

A randomized, placebo-controlled, double-blind trial was performed on 95 patients (47-placebo and 48-vitamin D groups). Participants were randomized using a randomization table to a single dose of either vitamin D (300,000 IU, IM) or a matching placebo. Fasting blood sugar (FBS), glycosylated hemoglobin (HbA1c), 25(OH)Vit D and high-sensitivity C-reactive protein (hs-CRP) were measured at baseline and at 8 weeks.

RESULTS

No significant differences in baseline values were noted between groups, except in HbA1c, which was lower in the placebo group. In the supplemented group, the level of serum 25(OH)Vit D increased (29.6 ± 20.8 vs. 44.5 ± 19.2 ng/mL) and those of FBS and HbA1c decreased significantly [186.5 ± 64.1 vs. 165.1 ± 58.5 mg/dL and 8.2 ± 2.0 % (66.3 ± 21.8 mmol/mol) vs. 7.7 ± 1.8 % (61.7 ± 20.0 mmol/mol), respectively] (all p < 0.05), and no changes, however, were observed in the placebo group. We also compared change of marginal means of outcome variables (HbA1c, FBS, 25(OH)Vit D and hs-CRP) from baseline between the vitamin D versus placebo group, using ANCOVA, adjusted for the baseline of each variable itself, season at study entry, age and body mass index. During trial, only HbA1c level decreased significantly [0.48 % (standard error: 0.17), p = 0.04]. No any adverse effect was seen.

CONCLUSIONS

A single parenteral dose of vitamin D in T2D patients with IHD improved glycemic control, but not inflammatory status.

CLINICAL TRIAL REGISTRY

Australian New Zealand Clinical Trial Registry.

CLINICAL TRIAL NUMBER

ACTRN12614000529640.

Vitamin D-Fortified Bread Is as Effective as Supplement in Improving Vitamin D Status: A Randomized Clinical Trial

CONTEXT

Bread can potentially be a suitable vehicle for fortification with vitamin D.

OBJECTIVE

This study was undertaken to evaluate the following: 1) the bioavailability of vitamin D from the fortified Iranian bread and 2) the possible effects of daily consumption of the fortified bread on certain health aspects.

DESIGN, SETTING, AND PARTICIPANTS

This was a randomized, double-blind, placebo-controlled trial conducted over 8 weeks in 90 healthy subjects aged 20-60 years.

INTERVENTION

Subjects were randomly allocated to one of three groups: 1) fortified bread (FP; 50 g bread fortified with 25 μg vitamin D3 plus placebo daily; n = 30); 2) supplement (SP; 50 g plain bread plus 25 μg vitamin D supplement daily; n = 30); and 3) control (CP; 50 g plain bread plus placebo daily; n = 30).

OUTCOME MEASURES

Initial and final anthropometric and biochemical assessments were performed.

RESULTS

The within-group changes of serum 25-hydroxyvitamin D concentrations were 39.0 ± 22.6 (P < .001), 28.9 ± 31.2 (P < .001), and -9.2 ± 12.3 nmol/L in the FP, SP, and CP groups, respectively. Only in FP and SP groups, serum intact PTH concentrations decreased approximately 13.5% and 14.5%, respectively. Visceral fat also showed a significant decrement in FP (-1.05% ± 1.4%; P ≤ .001) and SP (-0.96% ± 1.7%; P = .006). Serum low-density lipoprotein cholesterol concentration showed a within-group reduction in FP (-10.4 ± 11.2 mg/dL; P < .001) and an insignificant decrement in SP (-6.6 ± 20.2 mg/dL; P = .083). Serum high-density lipoprotein increased in both vitamin D-supplemented groups (FP: 9.7 ± 7.6 vs SP: 5.7 ± 6.7 mg/dL; P < .001).

CONCLUSION

Vitamin D-fortified bread could be potentially effective in raising circulating 25-hydroxyvitamin D levels of the population to nearly adequate levels.

Comparison of the Vitamin D Status of Children Younger and Older Than 2 Years in Tehran: Are Supplements Really Necessary?

BACKGROUND

Vitamin D is a vital lipid-soluble vitamin in the body, helping the growth and development of bones. Vitamin D deficiency in children has several adverse effects. The most important preventative factor is determining the deficiency at an early stage and prescribing vitamin D-containing supplements.

OBJECTIVES

To investigate the vitamin D status of children younger and older than 2 years and determine the utility of prescribing vitamin D supplements.

PATIENTS AND METHODS

Three hundred healthy children who attended the pediatric clinic for routine assessments were enrolled in this study. Their parents were asked to complete a questionnaire, which included questions about demographics, nutrition, and supplements. Blood levels of vitamin D, calcium, and phosphorus were then measured.

RESULTS

The final study consisted of 286 children, 140 males and 146 females, with a mean age of 4.46 ± 2.82 yr. Of these, 218 (76.22%) children, with a mean age of 5.09 ± 2.82 yr, had vitamin D deficiency, and 76 children (23.78%), with a mean age of 2.58 ± 1.88 yr, had normal vitamin D levels (P = 0.001). The mean level of vitamin D was 29.71 ± 14.42 ng/mL in 88 (30.8%) patients up to 2 years and 17.11 ± 14.02 ng/mL in 198 (69.2%) patients older than 2 years (P = 0.0001).

CONCLUSIONS

The vitamin D levels of children aged more than 2 years are lower than those of children aged less than 2 years. Thus, prescribing vitamin D-containing supplements in children older than 2 years may be beneficial.

Vitamin D Status among Young Children Aged 1-3 Years: A Cross-Sectional Study in Wuxi, China

BACKGROUND

The increasingly recognized importance of vitamin D has been discussed and vitamin D status among young children has attracted widespread attention in recent years. However, study on vitamin D status in young children aged 1-3 y is limited in China.

OBJECTIVE

To evaluate the nutritional vitamin D status of young children aged 1-3 y in Wuxi, southeastern China.

METHODS

A large cohort of 5,571 young children aged 1-3 y were recruited in this study who visited the child health clinics at the Wuxi Maternity and Child Health Hospital (latitude 31.57°N) during January 2014 to January 2015. Wuxi was located in southeastern China at a latitude of 31.57°N. Finger-stick blood sampling was conducted in all the subjects and serum 25-Hydroxyvitamin D (25(OH)D) levels were measured to evaluate their vitamin D status.

RESULTS

In this study, serum 25(OH)D levels of young children at the age of 1-3 years ranged from 20.6-132.9 nmol/L (Median: 71.5 nmol/L). 16.1% of the population had vitamin D deficiency (<50 nmol/L), while 38.8% of the subjects had a sufficient (50-74.9 nmol/L) vitamin D level. An optimal vitamin D status (≥75 nmol/L) was found in 45.1% of the young children. The prevalence of vitamin D deficiency was higher in autumn (19.5%) than in summer (12.1%). There was no significant difference in vitamin D status between genders. The binary logistic regression analysis revealed that child age was strongly associated with vitamin D deficiency (adjusted OR: 1.173; 95%CI: 1.053-1.308; P = 0.004).

CONCLUSIONS

The prevalence of vitamin D deficiency was 16.1% among young children aged 1-3 y in Wuxi. Season and child age were associated with their vitamin D status. It is implied that young children should receive adequate amounts of vitamin D supplementation and spend more time outdoors to prolong the sunlight exposure when they grow older.

Competitive Protein-binding assay-based Enzyme-immunoassay Method, Compared to High-pressure Liquid Chromatography, Has a Very Lower Diagnostic Value to Detect Vitamin D Deficiency in 9-12 Years Children

Background:

The most reliable indicator of Vitamin D status is circulating concentration of 25-hydroxycalciferol (25(OH) D) routinely determined by enzyme-immunoassays (EIA) methods. This study was performed to compare commonly used competitive protein-binding assays (CPBA)-based EIA with the gold standard, high-pressure liquid chromatography (HPLC).

Methods:

Concentrations of 25(OH) D in sera from 257 randomly selected school children aged 9–11 years were determined by two methods of CPBA and HPLC.

Results:

Mean 25(OH) D concentration was 22 ± 18.8 and 21.9 ± 15.6 nmol/L by CPBA and HPLC, respectively. However, mean 25(OH) D concentrations of the two methods became different after excluding undetectable samples (25.1 ± 18.9 vs. 29 ± 14.5 nmol/L, respectively; P = 0.04). Based on predefined Vitamin D deficiency as 25(OH) D < 12.5 nmol/L, CPBA sensitivity and specificity were 44.2% and 60.6%, respectively, compared to HPLC. In receiver operating characteristic curve analysis, the best cut-offs for CPBA was 5.8 nmol/L, which gave 82% sensitivity, but specificity was 17%.

Conclusions:

Though CPBA may be used as a screening tool, more reliable methods are needed for diagnostic purposes.

The association of vitamin D deficiency with psychiatric distress and violence behaviors in Iranian adolescents: the CASPIAN-III study

Background

Subtle effects of vitamin D deficiency on behavior have been suggested. We investigated the association of vitamin D status with mental health and violence behaviors in a sample of Iranian adolescents.

Methods

This nationwide study was conducted in 2009–2010 in 1095 Iranian school students with mean age 14.7 ± 2.6 years. Items were adapted from the Global School-based Student Health Survey (GSHS). Psychiatric distress was considered as the self-reported anger, anxiety, poor quality sleep, confusion, sadness/depression, worry, and violence-related behaviors (physical fight, having bully, or getting bullied).

Results

Forty percent had serum 25(OH)D values below 10 ng/mL (vitamin D deficient), and 39 % had levels 10-30 ng/mL (vitamin D insufficient). The prevalence of self-reported anger, anxiety, poor quality sleep, sadness/depression, and worry was significantly lower (P < 0.05) in vitamin D sufficient participants compared with their other counterparts. The odds of reporting anger, anxiety, poor quality sleep, and worry, increased approximately 1.5 to 1.8 times in vitamin D insufficient compared with normal children and adolescents (P < 0.05). Risk estimates indicated that vitamin D insufficient and deficient subjects had higher odds of reporting worry compared to normal vitamin D group [OR = 2.417 (95 % CI: 1.483-3.940) for vitamin D insufficient students, and OR = 2.209 (95 % CI: 1.351-3.611) for vitamin D deficient students] (P-trend = 0.001). Violence behaviors did not show any association with vitamin D status (P > 0.05).

Conclusion

Some psychiatric distress such as anger, anxiety, poor quality sleep, depression, and worry are associated with hypovitaminosis D in adolescents. The clinical significance of the current findings should be determined in future longitudinal studies.

Vitamin D deficiency and its associated risk factors in children and adolescents in southern Iran

OBJECTIVES

To evaluate prevalence of vitamin D deficiency and its associated factors in southern Iranian children.

DESIGN

Cross-sectional study. Anthropometric and pubertal characteristics were assessed by a trained physician. Physical activity and sun exposure were evaluated using standard questionnaires. Body composition measurements were performed using dual-energy X-ray absorptiometry. Serum Ca, P alkaline phosphatase and 25-hydroxyvitamin D (25(OH)D) were assessed in all children. Statistical analysis was done using the statistical software package IBM SPSS Statistics 18·0.

SUBJECTS

Iranian children (n 477) aged 9-18 years.

SETTING

Fars Province, Iran, 2011.

RESULTS

Of the children, 81·3 % were 25(OH)D deficient. There was no significant difference in 25(OH)D concentration between boys and girls (P=0·3). 25(OH)D concentration was associated with BMI (r=-0·1, P=0·02), pubertal status (r=-0·08, P=0·04) and sun exposure (r=0·10, P=0·04). Fat mass index was associated with 25(OH)D concentration (r=-0·13, P=0·03), but not lean mass index (P=0·86). In multiple regression analysis with adjustment for confounding factors, age and puberty were found to be independently associated with 25(OH)D concentration (P=0·008 and P=0·006); there was a significant correlation between exercise and 25(OH)D concentration after adjustment for either BMI (P=0·01) or fat mass index (P=0·02).

CONCLUSIONS

25(OH)D deficiency is highly prevalent among children in the south of Iran. It is related to insufficient sun exposure, low physical activity, advancing age and pubertal stage. Measures should be taken to improve the health of southern Iranian children in this critical age group by preventing 25(OH)D deficiency.

Vitamin D status and its associations with components of metabolic syndrome in healthy children

AIM

High prevalence of vitamin D insufficiency/deficiency has been reported in populations of different countries. The aim of this cross-sectional study was to determine the prevalence and association of vitamin D status with components of metabolic syndrome.

METHODS

Lipid profile indices, anthropometric indices [body mass index and waist circumference (WC)], insulin resistance index (HOMA-IR), systolic blood pressure (SBP), diastolic blood pressure (DBP), C-reactive protein, intact parathyroid hormone (iPTH), and serum 25-hydroxyvitamin D [25(OH)D] concentration were evaluated in 297 healthy schoolchildren aged 7-11 years. Multivariate linear regression was used to determine independent predictors associated with low serum 25(OH)D concentrations.

RESULTS

The mean serum 25(OH)D concentration was 14.12±8.20 ng/mL (35.3±20.5 nmol/L); 96% of children had low serum 25(OH)D levels, 31.0% were deficient, and 65.0% had insufficient levels of 25(OH)D. Vitamin D deficiency was higher in girls (χ²=13.66; p=0.00); 25(OH)D level was negatively associated with WC, HOMA-IR, SBP, DBP, and iPTH. In the multivariate model, WC, DBP, and HOMA-IR were significant independent predictor of low 25(OH)D concentrations.

CONCLUSION

The prevalence of low vitamin D level in the studied healthy children was high and it is correlated with some components of metabolic syndrome. Outdoor activity for optimum sun exposure and additional studies are needed to evaluate the underlying metabolic syndrome components and hypovitaminosis D complications.

Vitamin D deficiency and its predictors in a country with thirteen months of sunshine: the case of school children in central Ethiopia

Studies examining vitamin D status among children living in sunny climates indicated that children did not receive adequate vitamin D, however, this has not been looked at among children living in Ethiopia. In this study, we determined vitamin D deficiency and its predictors among school children aged 11–18 years, examining circulating 25-hydroxy vitamin D [25(OH)D]. The school-based cross-sectional study was conducted in schools in Adama Town (n = 89) and in rural Adama (n = 85) for a total sample of 174. Students were randomly selected using multi-stage stratified sampling method from both settings. Socioeconomic status of parents and demographic, anthropometric, sun exposure status and blood 25(OH)D levels were obtained. Vitamin D deficiency, defined as circulating levels of 25(OH)D <50 nmol/L, was found in 42% of the entire study participants. Prevalence of deficiency was significantly higher among students in urban setting compared to rural (61.8% vs 21.2%, respectively, p<0.001). After controlling for potential confounders using multivariable logistic regression model, duration of exposure to sunlight, amount of body part exposed to sunlight, place of residence, maternal education, body fatness, having TV/computer at home and socioeconomic status were significant predictors of vitamin D deficiency. The findings suggest that Vitamin D deficiency was prevalent in healthy school children living both in urban and rural areas of a country with abundant year round sunshine providing UVB, with the prevalence of deficiency being significantly higher among urban school children who were less exposed to sunlight. Behaviour change communication to enhance exposure to ultraviolet light is critical to prevent vitamin D deficiency in tropical country like Ethiopia. Further study is required to assess the deleterious effect of its deficiency on bone mineral homeostasis of growing children in Ethiopia during their most critical period of bone development.

Calcium Intake, Major Dietary Sources and Bone Health Indicators in Iranian Primary School Children

Background:

Adequate calcium intake may have a crucial role with regards to prevention of many chronic diseases, including hypertension, hypercholesterolemia, different types of cancer, obesity and osteoporosis. In children, sufficient calcium intake is especially important to support the accelerated growth spurt during the preteen and teenage years and to increase bone mineral mass to lay the foundation for older age.

Objectives:

This study aimed to assess daily calcium intake in school-age children to ensure whether they fulfill the FGP dairy serving recommendations, the recommended levels of daily calcium intake and to assess the relationship between dietary calcium intake and major bone health indicators.

Patients and Methods:

A total of 501 Iranian school-age children were randomly selected. Calcium intake was assessed using a semi-quantitative food frequency questionnaire. Bone health indicators were also assessed.

Results:

Dairy products contributed to 69.3% of the total calcium intake of the children. Daily adequate intake of calcium was achieved by 17.8% of children. Only 29.8% met the Food guide pyramid recommendations for dairy intake. Dietary calcium intake was not significantly correlated with serum calcium and other selected biochemical indicators of bone health.

Conclusions:

The need for planning appropriate nutrition strategies for overcoming inadequate calcium intake in school age children in the city of Tehran is inevitable.