Serum 25-hydroxyvitamin D is associated with obesity and metabolic parameters in US children

Association of Blood Calcidiol Levels and Metabolic Syndrome in Children and Adolescents With Vitamin D Deficiency

This retrospective cohort study aimed to determine whether severe calcidiol deficiency [25-hydroxyvitamin (OH)D <30 nmol/L] improvement has a beneficial effect on cardiometabolic parameters in children and adolescents (5-17 years) with or without metabolic syndrome (MetS). Logistic regression analysis was performed to test for multivariate associations between potential confounders and changes in vitamin D (VD) status from baseline to follow-up care when predicting binary categorical outcomes. Of 562 participants, 146 (26%) had MetS. Individuals with severe VD deficiency (VDD) were more likely to have MetS with elevated blood pressure than those with sufficient (≥75 nmol) VD levels (adjusted odds ratio [AOR], 4.46; 1.08-18.43; p < .05) at follow-up. In the logistic regression model, every unit increase in VD across time decreased the odds of MetS (AOR, 0.98; 95% confidence interval: [0.96, 0.99]; p < .05). Improvement in VD status demonstrated a beneficial metabolic effect in children and adolescents with severe VDD.

Association between vitamin D and cardiovascular health in Chinese children and adolescents: Basing on Life's Essential 8

BACKGROUND AND AIMS

The relationship between vitamin D and cardiovascular health (CVH) in children remains unclear. We aimed to explore the association between vitamin D and CVH metrics using the latest Life's Essential 8 (LE8) among Chinese children and adolescents.

METHODS AND RESULTS

A cross-sectional study containing 2680 participants aged 7-18 years (1340 boys and 1340 girls) was performed in South China in 2013. Vitamin D levels were categorized as follows: ≥20 ng/mL (sufficiency), 12 - < 20 ng/mL (inadequacy), and <12 ng/mL (deficiency). The CVH metrics of LE8 was assessed by overall CVH score, health behavior score, health factor score and high CVH, among which the health behaviors included diet, physical activity, nicotine exposure, and sleep health, as well as the health factors contained body mass index, blood lipids, blood glucose, and blood pressure. Different regression models were used to assess the associations between vitamin D levels and CVH metrics of LE8. Results showed that the prevalence of vitamin D deficiency and inadequacy was 7.5% and 44.4%, respectively. Boys had lower levels in overall CVH score, health behavior score, and health factor score than girls. After adjusting for potential confounds, upward trends in diet score, health behavior score, and high CVH were observed with increasing vitamin D levels.

CONCLUSION

Vitamin D levels were positively associated with high CVH based on LE8, and more attention should be paid on boys due to whose lower levels in CVH metrics.

Serum 25-Hydroxyvitamin D Is Associated With Prediabetes, Type 2 Diabetes Mellitus, and Insulin Resistance in Children: A Systematic Review and Dose-Response Meta-analysis of Epidemiologic Studies

CONTEXT

Although several investigations have been conducted on the association between serum vitamin D levels and prediabetes and type 2 diabetes mellitus (T2DM) in children and adolescents, their findings are inconsistent.

OBJECTIVE

We conducted a systematic review and dose-response meta-analysis to summarize this subject.

DATA SOURCES

The electronic databases of ISI Web of Science, Scopus, PubMed, and motor engineering of Google Scholar were comprehensively searched up to May 2023.

DATA EXTRACTION

Epidemiologic studies that investigated the risk of hyperglycemia and insulin resistance in relation to serum 25-hydroxy vitamin D levels in children and adolescents were included.

DATA ANALYSIS

Twenty-two investigations, with a total of 38 622 participants, were systematically reviewed. Meta-analysis of 15 studies (n = 32 720 participants) showed that participants with the highest serum vitamin D levels had 42% lower risk of hyperglycemia, compared with those in the lowest category of serum vitamin D levels (relative risk [RR] = 0.58; 95%CI, 0.48, 0.71). Moreover, pooling 8 studies (n = 10 465 participants) illustrated that highest serum vitamin D level was associated with a 44% lower risk of insulin resistance compared with the lowest serum vitamin D level (RR = 0.56; 95%CI, 0.37, 0.83). Based on linear dose-response analysis, each 10 nmol/L increment in serum 25-hydroxy vitamin D was associated with a 6% decreased risk of hyperglycemia and insulin resistance in children. Furthermore, nonlinear dose-response analysis revealed that increasing serum vitamin D concentration from 40 nmol/L to sufficient values (>50 nmol/L) was associated with a decreasing trend in risk of hyperglycemia and insulin resistance.

CONCLUSION

This meta-analysis revealed inverse associations between serum vitamin D levels and hyperglycemia and insulin resistance in children and adolescents, in a dose-response manner. Increasing serum vitamin D concentration from 40 nmol/L to sufficient values (>50 nmol/L) was associated with a decreasing trend in hyperglycemia and insulin resistance risk. Systematic Review Registration: PROSPERO registration no. CRD42023458155.

The association between serum vitamin D levels and abnormal lipid profile in pediatrics: A GRADE-assessed systematic review and dose-response meta-analysis of epidemiologic studies

CONTEXT

Several studies have investigated the relationship between serum vitamin D and dyslipidemia in children and adolescents, but the findings have been contradictory.

OBJECTIVE

The current systematic review and dose-response meta-analysis investigated the serum vitamin D - dyslipidemia relationship in children and adolescents.

DATA SOURCES

ISI Web of Science, Scopus, MEDLINE (PubMed), EMBASE databases, and Google Scholar, were searched up to December 2022.

DATA EXTRACTION

Observational studies that investigated the odds of dyslipidemia in categories of serum vitamin D levels in children were included, and their data were extracted.

DATA ANALYSIS

Pooling of 17 effect sizes from 15 studies (39 342 participants) showed that subjects with higher serum vitamin D had 27% lower odds of hypertriglyceridemia (odds ratio [OR] = 0.73; 95% confidence interval [CI]: 0.60, 0.88). A meta-analysis of 18 effect sizes from 16 studies (39 718 participants) illustrated that highest vs lowest serum vitamin D was related to 22% lower odds of low high-density lipoprotein cholesterol (HDL-c) (OR = 0.78; 95% CI: 0.66, 0.91). Also, a nonlinear association between serum vitamin D and odds of abnormal lipid profile was found: elevating values of 25-hydroxyvitamin D from 35 nmol/L to 55 nmol/L was associated with a decreasing trend in odds of hypertriglyceridemia, hyper low-density lipoprotein cholesterolemia, hypercholesterolemia, and hypo HDL-cholesterolemia. However, no significant linear association was observed. Based on the Grading of Recommendations, Assessment, Development and Evaluations (GRADE), the certainty of all evidence was rated as high.

CONCLUSION

This meta-analysis revealed that the level of 25-hydroxyvitamin D was inversely related to odds of abnormal serum triglycerides and HDL-c in children and adolescents. Increasing serum vitamin D from 35 nmol/L to 55 nmol/L was associated with a decreasing trend in the odds of abnormal serum triglycerides, HDL-c, low-density lipoprotein cholesterol, and total cholesterol in children.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. 42023400787.

Seasonal and sex-related variation in vitamin D status and its association with other biochemical markers in young individuals: A cross-sectional study

BACKGROUND

While several studies have investigated the association between vitamin D deficiency and biochemical parameters, the results are still inconsistent and mostly overlook seasonal variations. This study explored the relationships between 25-hydroxy-vitamin D (25(OH)D) concentrations, biochemical markers, and seasonal variation among young males and females.

METHODS

A cross-sectional study was conducted among 203 individuals aged 18-24 years of both sexes residing in Brasilia, Brazil (latitude: 15°S). Sociodemographic variables, season of blood collection, and serum levels of 25(OH)D, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, glycated hemoglobin (HbA1c), glucose, insulin, hs-CRP, parathyroid hormone, ionized calcium, and alkaline phosphatase were included. Descriptive statistics and differences among groups, correlations, and linear regression tests were performed.

RESULTS

The mean age of the participants was 21.17±1.7 years, and the mean serum 25(OH)D level was 25.76±7.0 ng/mL. Of the participants, 50.7% had vitamin D insufficiency (20 to 29.9 ng/mL), and 23.2% were vitamin D deficient (≤20 ng/mL). Vitamin D deficiency was higher in the spring (53.2%) and among females (29.5%). In young men with vitamin D insufficiency/deficiency (≤29.9 ng/mL) (n = 49), 25(OH)D levels were inversely correlated with HOMA-β (r = -0.234, p = 0.032) and triglyceride (r = -0.415, p = 0.003) levels. However, there were no significant correlations between 25(OH)D concentrations and biochemical markers among women with insufficient and deficient vitamin D levels.

CONCLUSION

This study found a high prevalence of vitamin D insufficiency/deficiency among young individuals living in Brasília, Brazil, particularly women and during the spring season. Our findings suggest that lower 25(OH)D levels (≤29.9 ng/mL) may be associated with insulin resistance and an increased risk of cardiovascular disease in young men studied. However, further studies with larger representative samples are needed to explore the mechanisms underlying the association between vitamin D and biochemical parameters.

Vitamin D status in healthy Italian school-age children: a single-center cross-sectional study

BACKGROUND

Vitamin D is involved in calcium homeostasis and bone metabolism, although its extra-skeletal actions are also well-known. Low serum 25(OH)D levels are common both in adults and children worldwide.

METHODS

The purpose of this cross-sectional study was to determine the distribution of 25(OH)D levels in a cohort of healthy Italian school-age children, aged 5-10 years, in relationship to determinants of vitamin D deficiency such as season, BMI, gender, age and ethnicity.

RESULTS

The mean serum 25(OH) D level was 28.2 ng/mL; the prevalence of 25(OH)D sufficiency (> 30 ng/mL), insufficiency (20-30 ng/mL), deficiency (10-20 ng/mL) and severe deficiency (< 10 ng/mL) was 36%, 37%, 21% and 6% of the study-group population, respectively. The lower serum 25(OH)D values were observed during winter (21.6 ng/mL) and spring (22.9 ng/mL), as compared to summer (46.7 ng/mL) (p < 0.001). Higher BMI z-scores were associated with lower 25(OH)D level while no statistical difference was observed as related to gender and age groups.

CONCLUSIONS

Healthy Italian schoolchildren show low 25(OH)D levels, particularly during winter and spring time. Seasonality, ethnicity and overweight/obesity were confirmed to influence the vitamin D status, thus indicating the need for effective initiatives to support adequate vitamin D status in this population group.

High Prevalence of Hypovitaminosis D in Adolescents Attending a Reference Centre for the Treatment of Obesity in Switzerland

Background: Hypovitaminosis D is common in populations with obesity. This study aimed at assessing (1) the prevalence of hypovitaminosis D and (2) the associations between vitamin D levels and cardiovascular risk factors in adolescents attending a reference centre for the treatment of obesity. Design: Cross-sectional pilot study conducted in the paediatric obesity unit of the Lausanne university hospital, Switzerland. Methods: Participants were considered eligible if they (1) were aged between 10 to 16.9 years and (2) consulted between 2017 and 2021. Participants were excluded if (1) they lacked vitamin D measurements or (2) the vitamin D measurement was performed one month after the base anthropometric assessment. Hypovitaminosis D was considered if the vitamin D level was <30 ng/mL (<75 nmol/L). Severe obesity was defined as a BMI z-score > 3 SD. Results: We included 52 adolescents (31% girls, mean age 13 ± 2 years, 33% with severe obesity). The prevalence of hypovitaminosis D was 87.5% in girls and 88.9% in boys. The vitamin D levels were inversely associated with BMI, Spearman r and 95% CI: −0.286 (−0.555; −0.017), p = 0.037; they were not associated with the BMI z-score: −0.052 (−0.327; 0.224), p = 0.713. The vitamin D levels were negatively associated with the parathormone levels (−0.353 (−0.667; −0.039), p = 0.028) and positively associated with the calcium levels (0.385 (0.061; 0.708), p = 0.020), while no association was found between vitamin D levels and blood pressure and lipid or glucose levels. Conclusion: almost 9 out of 10 adolescents with obesity in our cohort presented with hypovitaminosis D. Hypovitaminosis D does not seem to be associated with a higher cardiovascular risk profile in this group.

Association between anthropometric markers of adiposity, adipokines and vitamin D levels

Inverse association between serum levels of vitamin D and obesity has been pointed out in several studies. Our aim was to identify to the associations between vitamin D levels and a large panel of anthropometric markers and adipokines. Cross-sectional study including 6485 participants. Anthropometric markers included body mass index (BMI), % body fat, waist, waist-to-hip (WHR), waist-to-height (WHtR), conicity index, body roundness index (BRI) and a body shape index (ABSI). 55.7% of women and 60.1% of men presented with vitamin D deficiency. Vitamin D levels were negatively associated with most anthropometric markers, with correlation coefficients ranging between −0.017 (ABSI) and −0.192 (BMI) in women and between −0.026 (weight) and −0.130 (% body fat) in men. Vitamin D levels were inversely associated with leptin levels in both sexes and positively associated with adiponectin levels in women only. The likelihood of vitamin D deficiency increased with increasing adiposity levels, except for ABSI (women) and BMI (men). Total body fat, rather than localized or unevenly distributed body fat, is the adiposity marker most associated with decreased vitamin D levels. Monitoring vitamin D levels in people with overweight/obesity is essential.

Adiposity Metabolic Consequences for Adolescent Bone Health

Infancy and adolescence are crucial periods for bone health, since they are characterized by intense physical growth and bone development. The unsatisfactory acquisition of bone mass in this phase has consequences in adult life and increases the risk of developing bone diseases at more advanced ages. Nutrient deficiencies, especially calcium and vitamin D, associated with a sedentary lifestyle; lack of sun exposure; and epigenetic aspects represent some of the main risk factors for poor bone quality. In addition, recent studies relate childhood obesity to impaired bone health; however, studies on the adiposity effects on bone health are scarce and inconclusive. Another gap concerns the implications of obesity on child sexual maturity, which can jeopardize their genetic potential bone mass and increase fracture risk. Therefore, we reviewed the analyzed factors related to bone health and their association with obesity and metabolic syndrome in adolescents. We concluded that obesity (specifically, accumulated visceral fat) harms bones in the infant–juvenile phase, thereby increasing osteopenia/osteoporosis in adults and the elderly. Thus, it becomes evident that forming and maintaining healthy eating habits is necessary during infancy and adolescence to reduce the risk of fractures caused by bone-metabolic diseases in adulthood and to promote healthy ageing.

Vitamin D and Obesity/Adiposity—A Brief Overview of Recent Studies

Observational studies classically find an inverse relationship between human plasma 25-hydroxyvitamin D concentration and obesity. However, interventional and genetic studies have failed to provide clear conclusions on the causal effect of vitamin D on obesity/adiposity. Likewise, vitamin D supplementation in obese rodents has mostly failed to improve obesity parameters, whereas several lines of evidence in rodents and prospective studies in humans point to a preventive effect of vitamin D supplementation on the onset of obesity. Recent studies investigating the impact of maternal vitamin D deficiency in women and in rodent models on adipose tissue biology programming in offspring further support a preventive metabolically driven effect of vitamin D sufficiency. The aim of this review is to summarize the state of the knowledge on the relationship between vitamin D and obesity/adiposity in humans and in rodents and the impact of maternal vitamin D deficiency on the metabolic trajectory of the offspring.

Vitamin D Trajectories and Cardiometabolic Risk Factors During Childhood: A Large Population-Based Prospective Cohort Study

Background and Objectives

Vitamin D has been indicated to play an important role in the optimal function of the cardiovascular system. However, with limited evidence, it remains unclear whether vitamin D status transition during childhood would affect cardiometabolic risk factors. Thus, we aimed to identify the associations of the longitudinal trajectory of vitamin D status with cardiometabolic risk factors in children.

Methods

A total of 10,482 participants with complete follow-up records from a large population-based prospective cohort study were included in this analysis. The 25-hydroxyvitamin D [25(OH)D] concentrations, blood pressure, blood lipids, and fasting blood glucose were determined. Vitamin D deficiency was defined as serum 25(OH)D concentrations below 30 nmol/L according to the Institute of Medicine recommendations. Based on the vitamin D status at baseline and follow-up, we identified four possible trajectories: (1) persistent non-deficiency (reference); (2) baseline non-deficiency to follow-up deficiency; (3) baseline deficiency to follow-up non-deficiency; (4) persistent deficiency. The relationships between cardiometabolic risk factors and vitamin D trajectories were evaluated using adjusted risk ratios (RRs).

Results

Overall, 35.1 and 24.2% of participants had vitamin D deficiency at the baseline and follow-up, respectively, and 15.1% were under the condition of persistent vitamin D deficiency. Compared to children with persistent non-deficiency, those who shifted from non-deficiency at baseline to deficiency at follow-up had a 2.09-fold (95% CI: 1.36, 3.23) increased risk of high triglyceride (TG). Besides, children with altered vitamin D status from deficiency to non-deficiency during follow-up were still at a significantly higher risk of high total cholesterol (TC) than the reference group [RR (95% CI): 1.39 (1.04, 1.86)]. Finally, children with persistent vitamin D deficiency were at the highest risks of high TC [RR (95% CI): 1.61 (1.18, 2.19), P _trend < 0.001], high low-density lipoprotein cholesterol (LDL-C) [RR (95% CI): 1.53 (1.04, 2.27), P _trend = 0.046], and high TG [RR (95% CI): 1.96 (1.34, 2.87), P _trend = 0.003].

Conclusion

Our results suggest that persistent vitamin D deficiency might increase the risk of dyslipidemia in children, and vitamin D deficiency could have has short- and long-term effects on TG and TC, respectively.

Serum Vitamin D Levels in Relation to Abdominal Obesity in Children and Adolescents: A Systematic Review and Dose-Response Meta-Analysis

Background

Findings of epidemiological studies that investigated the relationship between serum vitamin D levels and abdominal obesity were inconsistent. To evaluate the relationship between blood vitamin D levels and abdominal obesity in children and adolescents, we did a comprehensive review and dose-response meta-analysis.

Methods

A comprehensive search in electronic databases including Scopus, Web of Science (ISI), MEDLINE (Pubmed), EMBASE, and Google Scholar was conducted, up to May 2021, for epidemiological studies that investigated the linkage between serum vitamin D levels (as the exposure) and abdominal obesity (as the outcome) in children and adolescents.

Results

Combining 19 effect sizes from 14 cross-sectional studies that included 29,353 apparently healthy children illustrated that the highest vs. lowest level of serum vitamin D was related to a 35% reduced odds of abdominal obesity [odds ratio (OR): 0.65; 95% CI: 0.50, 0.84]. Linear dose-response analysis revealed that each 10 ng/ml increase in serum vitamin D levels was related to a 7% decrease in odds of abdominal obesity (OR: 0.93; 95% CI: 0.90, 0.95), only among investigations that used percentiles of waist circumference (>75th or 90th) to define the disorder (including 6,868 total subjects and 1,075 cases with abdominal obesity). Increasing serum vitamin D levels from 20 to 40 ng/ml was related to reduce odds of abdominal obesity in children.

Conclusion

A negative relationship between blood vitamin D levels and abdominal obesity in children and adolescents was discovered in this meta-analysis of epidemiologic studies. Among investigations that used waist circumference percentiles to define the disorder, the relationship was in a dose-response manner. To affirm this relationship, more research studies are needed, particularly using a prospective design.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021261319, PROSPERO 2021, identifier: CRD42021261319.

Association of vitamin D status and cardio-metabolic risk factors in children and adolescents: the CASPIAN-V study

BACKGROUND

Metabolic syndrome (MetS) starts from early life and is one of the important underlying factors for non-communicable diseases (NCDs) in adulthood. Controversial evidence exists on the role of vitamin D deficiency in increasing the risk of pediatric MetS.

OBJECTIVE

This study aimed to assess the relationship between vitamin D level with MetS and its components in children and adolescents.

METHODS

This nationwide cross-sectional study was performed as part of a surveillance program in Iran. Participants were 2596 students, aged 7 to 18 years, living in 30 provinces. In addition to filling questionnaires, a physical examination was conducted, and blood samples were collected. The serum concentration of 25-hydroxy vitamin D (25(OH)D) was measured using the direct competitive immunoassay chemiluminescence method.

RESULTS

2596 students with a mean age of 12.2 y (55.1% boys) were recruited. Prevalence of vitamin D deficiency and insufficiency in participants was 10.6% (n = 276), and 60.5% (n = 1570), respectively. The prevalence of MetS was higher in the vitamin D deficient group. Students with deficient vitamin D levels had higher odds of MetS (OR: 4.25, 95%CI: 2.26-7.98), abdominal obesity (OR: 2.24, 95%CI: 1.61-3.12), low HDL-C (OR: 1.65, 95%CI: 1.18-2.30) and high fasting blood sugar (OR: 2.56, 95%CI: 1.43-4.57) in comparison to those with sufficient level of vitamin D.

CONCLUSION

Vitamin D deficiency was associated with increased odds of MetS and its components in the Iranian pediatric population. These findings underscore the importance of prevention and control of vitamin D deficiency in preventative programs against NCDs.

Vitamin D supplementation and cardiometabolic risk factors among diverse schoolchildren: a randomized clinical trial

BACKGROUND

There remains a lack of evidence demonstrating a potential relationship between vitamin D and cardiometabolic risk among children.

OBJECTIVES

We examined the effect of 3 different dosages of vitamin D on cardiometabolic risk factors among children at risk of deficiency.

METHODS

Racially diverse schoolchildren aged 8-15 y were randomly assigned in a double-blind fashion to supplementation with 600, 1000, or 2000 IU vitamin D3/d for 6 mo. Changes in HDL cholesterol, triglycerides, LDL cholesterol, total cholesterol, and blood glucose over 6 mo and at 12 mo (6 mo post-supplementation) were assessed. Subgroup analyses were also performed by weight status and race.

RESULTS

Among 604 children, 40.9% were vitamin D-inadequate at baseline (<20 ng/mL; mean ± SD: 22.0 ± 6.8 ng/mL), 46.4% were overweight/obese, and 60.9% had ≥1 suboptimal blood lipids or glucose. Over 6 mo, serum 25-hydroxyvitamin D increased in all 3 dosage groups from baseline (mean ± SE change: 4.4 ± 0.6 ng/mL, 5.7 ± 0.7 ng/mL, and 10.7 ± 0.6 ng/mL for 600, 1000, and 2000 IU/d, respectively; P < 0.001). Whereas HDL cholesterol and triglycerides increased in the 600 IU group (P = 0.002 and P = 0.02, respectively), LDL cholesterol and total cholesterol decreased across dosage groups. At 6 mo post-supplementation, HDL cholesterol remained elevated in the 600 and 1000 IU groups ( P < 0.001 and P = 0.02, respectively) whereas triglycerides remained elevated in the 1000 and 2000 IU groups (P = 0.04 and P = 0.006, respectively). The suppression of LDL cholesterol and total cholesterol persisted in the 2000 IU group only (P = 0.04 and P < 0.001, respectively). There were no significant changes in blood glucose and similar responses were observed overall by weight status and racial groups across dosages.

CONCLUSIONS

Vitamin D supplementation demonstrated generally positive effects on HDL cholesterol, LDL cholesterol, and total cholesterol, especially at the lower dosage of 600 IU/d, with several significant changes persisting during the post-supplementation period. Increases in triglycerides across dosage groups may be due to natural changes during adolescence warranting further study.This trial was registered at clinicaltrials.gov as NCT01537809.

Serum vitamin E concentration is negatively associated with body mass index change in girls not boys during adolescence

BACKGROUND

Vitamin E is the most abundant lipid-soluble antioxidants present in plasma; however, the relationship between serum vitamin E and change in body mass index (BMI)-for-age Z scores in adolescents has not been well described.

METHODS

This study is a cross-sectional study. Data were analyzed from 4014 adolescents who participated in the National Health and Nutrition Examination Survey. The nutritional status was calculated by BMI Z scores and was classified into normal weight, overweight, and obese. Multivariable-adjusted logistic regression was used to examine the association between serum vitamin E levels with overweight/obesity. Besides, the interaction effects between potential confounders and vitamin E on obesity were further evaluated.

RESULTS

After adjusting potential confounders, serum vitamin E levels were negatively associated with overweight/obesity in girls but not in boys. Per standard deviation increment in vitamin E concentrations was associated with a 92% decreased risk of obesity in females. Besides, lower quartiles of serum vitamin E were associated with a higher risk of overweight/obesity in girls. Moreover, the inverse association between serum vitamin E levels and obesity was also found in most subgroups through subgroup analysis.

CONCLUSIONS

Our study supports the negative association between serum vitamin E levels and overweight/obesity in adolescents. A higher serum vitamin E level may be associated with a reduced probability of obesity in girls, but not in boys.

What Is New in Pediatric Bone Health

BACKGROUND

This review paper aims to report on the last 5 years of relevant research on pediatric bone health in regard to nutrition and obesity, ethnic disparities, common orthopaedic conditions, trauma, spine, and sports medicine.

METHODS

A search of the PubMed database was completed using the following terms: bone health, Vitamin D, pediatric, adolescent, sports medicine, fractures, spine, scoliosis, race, ethnicity, obesity, Slipped Capital Femoral Epiphysis, Osteogenesis Imperfecta, Duchenne's Muscular Dystrophy, neuromuscular, and cancer. Resultant papers were reviewed by study authors and determined to be of quality and relevance for description in this review. Papers from January 1, 2015 to August 31, 2020 were included.

RESULTS

A total of 85 papers were selected for review. General results include 7 key findings. (1) Obesity inhibits pediatric bone health with leptin playing a major role in the process. (2) Socioeconomic and demographic disparities have shown to have a direct influence on bone health. (3) Vitamin D deficiency has been linked to an increased fracture risk and severity in children. (4) Formal vitamin D monitoring can aid with patient compliance with treatment. (5) Patients with chronic medical conditions are impacted by low vitamin D and need ongoing monitoring of their bone health to decrease their fracture risk. (6) Vitamin D deficiency in pediatrics has been correlated to low back pain, spondylolysis, and adolescent idiopathic scoliosis. Osteopenic patients with AIS have an increased risk of curve progression requiring surgery. Before spine fusion, preoperative screening for vitamin D deficiency may reduce complications of fractures, insufficient tissue repair, loosening hardware, and postoperative back pain. (7) Increasing youth sports participation has resulted in increased bone health related injuries. However, improved understanding of Relative Energy Deficiency in Sport effects on bone health has recently occurred.

CONCLUSIONS

Increasing awareness of bone health issues in children will improve their recognition and treatment. Further research is needed on diagnosis, treatment, outcomes, and most importantly prevention of pediatric bone health diseases.

Serum and Dietary Vitamin D in Individuals with Class II and III Obesity: Prevalence and Association with Metabolic Syndrome

The association between vitamin D deficiency and metabolic syndrome (MS) in severe obesity is unclear and controversial. We analyzed serum and dietary vitamin D and their association with MS in 150 adults with class II and III obesity (BMI ≥ 35 kg/m²) from the DieTBra Trial (NCT02463435). MS parameters were high fasting blood glucose, low HDL cholesterol, high triglycerides, elevated waist circumference, and hypertension. Vitamin D deficiency was considered as a level < 20 ng/mL. We performed multivariate Poisson regression adjusted for sociodemographic and lifestyle variables. The prevalence of serum vitamin D deficiency was 13.3% (mean 29.9 ± 9.4 ng/mL) and dietary vitamin D median was 51.3 IU/day. There were no significant associations between vitamin D, serum, and diet and sociodemographic variables, lifestyle, and class of obesity. Serum vitamin D deficiency was associated with age ≥ 50 years (p = 0.034). After a fully adjusted multivariate Poisson regression, MS and its parameters were not associated with serum or dietary vitamin D, except for lower HDL, which was associated with serum vitamin D deficiency (PR = 0.71, 95% CI 0.52–0.97; p = 0.029). Severe obese individuals had a low prevalence of vitamin D deficiency, which was not associated with MS.

Prevalence and factors associated with hypovitaminosis D in adolescents from a sunny country: Findings from the ERICA survey

Vitamin D plays a role in bone and metabolic health in life long, however hypovitaminosis D is common in different settings. The aim of this study was to describe vitamin D status among adolescents from a large sunny country and analyze associated factors. This was a multicenter, cross-sectional, school-based study. A total of 1152 adolescents age 12-17 from four Brazilian cities, Rio de Janeiro, Fortaleza, Brasília, and Porto Alegre, were included. Anthropometric variables, diet, type of school, race and season of data collection were evaluated. Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were measured and categorized into three levels: ≤ 20 ng/mL, 21-29 ng/mL and ≥ 30 ng/mL. Ordered logistic regression models were used to explore the factors associated with hypovitaminosis D. The prevalence of vitamin D levels below 20 ng/mL, between 21 and 29 ng/mL and above 30 ng/mL was 21 % (95 %CI: 19 %-24 %), 42 % (95 %CI: 39 %-46 %) and 37 % (95 %CI: 33 %-40 %), respectively. In the final adjusted model, hypovitaminosis D was positively associated with gender, center (latitudes), data collected in winter or spring, non-whites, and private school students. A higher proportional odds ratio (POR) for hypovitaminosis D was found among obese boys (POR = 2.2, 95 %CI: 1.1-4.5), but not girls. Adequate dietary intake of vitamin D was a protective factor (POR = 0.4, 95 %CI: 0.2-0.6) against hypovitaminosis D. In conclusion, there is a high prevalence of Brazilian adolescents at risk of hypovitaminosis D, independent of region. Due to their potential benefits, lifestyle changes should be stimulated, including healthier food choices and spending more time outdoors (with sun protection).

Adequate 25-hydroxyvitamin D levels are inversely associated with various cardiometabolic risk factors in Chinese children, especially obese children

OBJECTIVE

Vitamin D deficiency has recently evolved as a major public health issue worldwide. But the relationship between vitamin D and cardiovascular health in children remains unclear. Accordingly, we aimed to examine the associations between 25-hydroxyvitamin D (25(OH)D) concentrations and cardiometabolic risk factors, and to assess the possible effect modification of obesity on the associations in a Chinese pediatric population.

RESEARCH DESIGN AND METHODS

A cross-sectional sample of 6091 children aged 6-18 years was obtained using a cluster sampling method. The 25(OH)D concentrations, and metabolic risk factors, including waist to height ratio, blood pressure, blood lipids, fasting blood glucose (FBG), and insulin were measured. Adjusted ORs and multiplicative or additive interaction were calculated to assess the associations and effect modification, respectively.

RESULTS

Triglycerides, FBG, insulin, and homeostasis model assessment of insulin resistance were inversely associated with 25(OH)D concentrations (p<0.05) in both sexes. The OR of hyperglycemia among individuals with insufficient vitamin D was higher than those with adequate vitamin D after adjusting for covariates (OR: 1.47; 95% CI 1.26 to 1.70). Moreover, girls with insufficient vitamin D had significantly higher odds for hypertension and high total cholesterol than those with adequate vitamin D, which was not observed in boys. Thirty-two percent (95% CI 14% to 51%) of the increased odds of hyperglycemia can be explained by the interaction between insufficient vitamin D and obesity.

CONCLUSIONS

Vitamin D insufficiency is associated with increased odds of various cardiometabolic risk factors in Chinese children and has a synergistic effect on hyperglycemia with obesity.