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

Lower levels of vitamin D are associated with an increase in carotid intima-media thickness in children and adolescents with obesity

BACKGROUND

the relationship between vitamin D deficiency and carotid intima-media thickness (CIMT) in children and adolescents with obesity is unknown. The aim of this study was to investigate the correlation between vitamin D levels and CIMT in children and adolescents with obesity.

METHODS

a total of 440 children and adolescents aged 6-16 with obesity were included in the study. Anthropometric measurements, blood pressure measurements, blood lipids, blood glucose, and vitamin D levels were measured. Bilateral carotid ultrasound was performed to assess CIMT. The relationships between vitamin D levels and CIMT were assessed using multivariate linear regression with Generalized Linear Models and restricted cubic splines. Binary logistic regression analyses were conducted to explore the association between vitamin D status and the risk of abnormal CIMT.

RESULTS

vitamin D levels were inversely correlated with CIMT in subjects with serum 25-hydroxyvitamin D [25(OH)D] levels less than or equal to 50 nmol/L (ß = -0.147, 95 % CI [-0.263, -0.030], p = 0.013), but this correlation was not significant in subjects with serum 25(OH)D levels above 50 nmol/L. After correcting for various confounders, the risk of abnormal CIMT was significantly higher in the vitamin D deficiency group (OR = 2.080, 95 % CI [1.112, 3.891], p = 0.022).

CONCLUSIONS

vitamin D deficiency is an independent risk factor for abnormal CIMT, and vitamin D deficiency may play a promoting role in the atherosclerotic process in children and adolescents with obesity.

Correlation of salivary cytokine IL-17A and 1,25 dihydroxycholecalciferol in patients undergoing orthodontic treatment

The management of malocclusion has developed greatly in terms of treatment simulation and biomechanics, but treatment duration has been a great concern to the clinician as well as the patient. 1-25dihydroxycholecalciferol (biologically active form of Vitamin D) stimulates both osteoclasts and osteoblasts and was found to be the most significant in Orthodontic Tooth Movement acceleration. Inflammatory cytokines like IL-17A also play an important role in osteoclastogenesis and can enhance the rate of Orthodontic Tooth Movement.To perform a simultaneous evaluation of pro-inflammatory salivary cytokine IL-17A and salivary 1-25dihydroxycholecalciferol and to correlate their role on orthodontic tooth movement.A prospective cohort study was conducted among n = 97 patients. Saliva samples were collected from the patients at three phases of the orthodontic treatment, centrifuged and stored at 4℃ for evaluation of salivary 1-25dihydroxycholecalciferol levels and Pro-inflammatory cytokine IL-17A using ELISA.The mean salivary 1-25dihydoxycholecalciferol levels were 41.250 ng/ml, 33.246 ng/ml and 35.043 ng/ml during the initial phase, lag phase and post lag phase of orthodontic treatment. The mean pro-inflammatory cytokine IL-17 A levels were 107.79 pg/ml, 102.98 pg/ml and 66.156 pg/ml during the initial phase, lag phase and post lag phase of orthodontic treatment. There was a correlation between the salivary 1-25dihydroxycholecalciferol level and salivary cytokine IL-17A levels during the various phases of orthodontic treatment using Spearman's correlation rho test and linear regression analysis. There was no significant difference (p > 0.05) between 1-25dihydroxycholecalciferol levels and gender during the various phases (initial phase, lag phase and post lag phase) of Orthodontic treatment.There was a negative correlation between salivary 1-25dihydroxycholecalciferol level and salivary cytokine IL-17A levels during the various phases of orthodontic treatment. The level of 1-25dihydroxycholecalciferol and salivary cytokine IL-17A have been quantified during the various phases of Orthodontic treatment and this can be used clinically for the supplementation of Vitamin D in patients with low vitamin D levels and can enhance the treatment duration for the patient with less damaging effects to the surrounding tissues.

Association between 25-hydroxyvitamin D concentrations and pubertal timing: 6-14-year-old children and adolescents in the NHANES 2015-2016

Background

The association between 25(OH)D and pubertal timing has not been well studied. The aim of this study was to assess the relationship between 25(OH)D levels and pubertal timing in children.

Methods

Participants aged 6-14 years who had available nutritional and serum sex hormone (total testosterone (TT) and estradiol (E2)) information (n =1318) were included. We conducted a cross-sectional analysis of the associations between 25(OH)D and sex steroid hormones among children in the National Health and Nutrition Examination Survey, 2015-2016. Puberty was indicated by high levels of steroid hormones (TT≥50 ng/dL in men, E2≥20 pg/ml in women) or menarche.

Results

Serum 25(OH)D and pubertal status showed the same trend in both males and females. In the male population, the OR values of serum 25(OH)D between 50 and <75 and ≥75 nmol/L were 0.52 (0.25, 1.08) and 0.64 (0.23, 1.75), respectively, compared with serum 25(OH)D<50 nmol/L. The OR of serum 25(OH)D ≥50 nmol/L compared with <50 nmol/L was 0.54 (0.26, 1.10), and the P value was statistically significant (P=0.048). In the female population, when the serum 25(OH)D concentration was <50 nmol/L, the ORs corresponding to a serum 25(OH)D concentration between 50 and <75 and ≥75 nmol/L were 0.53 (0.29, 0.98) and 0.50 (0.19, 1.30), respectively. The OR of serum 25(OH)D≥50 nmol/L compared with <50 nmol/L was 0.52 (0.19, 0.96), and the P value was statistically significant (P=0.037).

Conclusions

A lower 25(OH)D level was associated with earlier puberty in both girls and boys. There was a negative association between 25(OH)D concentrations and pubertal timing.

Effects of vitamin D on sex steroids, luteinizing hormone, and testosterone to luteinizing hormone ratio in 307 infertile men

OBJECTIVE

Vitamin D status has been associated with sex steroid production. The question is whether vitamin D supplementation has an impact on sex steroid production in infertile men with vitamin D insufficiency?

DESIGN

A single-center, double-blinded, randomized clinical trial. Differences in sex steroids and reproductive hormones were predefined secondary outcomes, vitamin D status at baseline was a predefined subgroup and the primary outcome was differences in semen quality.

METHODS

A total of 307 infertile men were included and randomized 1:1 to active or placebo treatment for 150 days. Men in the active group initially received an oral bolus of 300,000 IU cholecalciferol, followed by daily supplementation with 1400 IU cholecalciferol and 500 mg calcium.

RESULTS

After intervention, no differences were found in serum concentrations of sex steroids, luteinizing hormone, testosterone/luteinizing hormone ratio or SHBG between the vitamin D and placebo group. However, in a predefined subgroup analysis of men with serum 25OHD ≤ 50 nmol/L, men treated with vitamin D had a significantly higher testosterone/luteinizing hormone ratio [4.2 (3.8-4.4) vs. 3.7 (3.4-4.0); p = 0.033] compared with placebo treatment. In men with vitamin D deficiency, the difference between groups was larger but not significant due to few men with serum 25OHD < 25 nmol/L.

CONCLUSION

Vitamin D + calcium supplementation did not alter sex steroid production in infertile men. However, vitamin D insufficient men treated with vitamin D supplementation had a significantly higher testosterone/LH ratio compared with placebo-treated men, suggesting that optimal Leydig cell function are dependent on adequate vitamin D status.

Association of serum 25-hydroxyvitamin D with bone health measured by calcaneal quantitative ultrasound: a large cross-sectional analysis in children and adolescents

Background: Vitamin D plays a crucial role in bone health; however, findings in children and adolescents remain inconsistent, and few studies have examined its impact on bone health measured by quantitative ultrasound (QUS). This study aims at assessing the relationship between serum vitamin D levels and bone health, as evaluated by QUS, across varying pubertal stages and genders. Methods: A baseline cross-sectional survey of an ongoing cohort study included 4682 children and adolescents aged 6 to 18 years from Shenzhen, China. Serum levels of 25-hydroxyvitamin D (25(OH)D), which is the sum of 25(OH)D2 and 25(OH)D3, were quantified using liquid chromatography-mass spectrometry. Bone health was measured through calcaneal QUS, utilizing the speed of sound (SOS) in the heel as a principal measure-a higher SOS indicating a denser bone structure. Generalized linear models were used to evaluate the association of serum 25(OH)D, 25(OH)D2, and 25(OH)D3 levels with the SOS. Results: Forty-one point-one percent of this population was vitamin D deficient (serum 25(OH)D < 20 ng ml-1), with only 11.1% being sufficient. In the fully adjusted model, we observed a significant positive association between increased serum 25(OH)D quartiles and SOS. Compared with the participants in the lowest quartiles of serum 25(OH)D, those in successive quartiles of 25(OH)D were 3.54 (95% CI: 0.81, 6.28) m s-1, 5.74 (95% CI: 2.87, 8.61) m s-1, and 8.83 (95% CI: 5.83, 11.84) m s-1, respectively (P for trend < 0.0001). The correlations observed for serum 25(OH)D2 and 25(OH)D3 with SOS were similar to those of serum 25(OH)D. Importantly, this association was primarily observed in post-pubertal children and adolescents but was absent in pre- and mid-pubertal participants (P for interaction = 0.0004). Conclusion: Elevated serum 25(OH)D levels were associated with better bone health, as measured through calcaneal QUS, in children and adolescents, particularly among those who had reached the post-pubertal stage. These findings highlight the crucial importance of maintaining sufficient vitamin D levels to support optimal bone health in this demographic.

The Value of an Ecological Approach to Improve the Precision of Nutritional Assessment: Addressing Contributors and Implications of the "Multiple Burdens of Malnutrition"

Globally, children are exposed to multiple health risks associated with diet and nutrition. Rather than simply being a condition of having too much or too little food, malnutrition is more a syndrome comprising multiple burdens of coexisting and reciprocal malnutrition, infection, or other conditions. Importantly, children with such syndromes (e.g., stunting and anemia, which are neither specific nor necessarily sensitive to nutritional status) are more likely to also have irreversible functional outcomes such as poor growth, impaired immune function, or cognitive delays. The global health community has identified nutrition-related targets (e.g., Sustainable Development Goals (SDGs) and World Health Organization (WHO) Global Nutrition Targets) that, for multiple reasons, are difficult to address. Moreover, as the complexity of the global health context increases with persistent pandemics of infectious diseases and the rising prevalence of noncommunicable diseases, there is a growing appreciation that conditions selected as nutrition/health targets indeed represent syndromes for which nutritional status serves as both an input and outcome. In recognition of the impact of these combined challenges and the role of the multiple manifestations of malnutrition, we suggest an approach to nutritional assessment that is intended to improve the precision of context-specific, equitable approaches to health promotion, disease prevention, and treatment.

Monthly versus daily administration of vitamin D3 in children: a retrospective propensity score-matched study

Objectives

We aimed to evaluate the efficacy and safety of monthly vitamin D3 administration compared to a daily dosing regimen in healthy children with vitamin D deficiency.

Methods

This retrospective study included vitamin D deficient (serum 25-hydroxyvitamin D [25(OH)D] < 20 ng/mL) children with precocious puberty who received gonadotropin-releasing hormone agonist every 4 weeks between December 2019 and November 2022. We used propensity scores to 1:1 match daily (1,000 IU daily) and monthly (25,000 IU per 4 weeks) administration of vitamin D3 based on age, sex, body mass index Z-scores, season of blood collection, and baseline serum 25(OH)D concentrations.

Results

Of 299 children, 192 were matched based on propensity scores (126 girls and 66 boys, 10.5 ± 1.4years). After a mean follow-up of 5.9 months (standard deviation [SD] 2.5 months), the monthly group showed a statistically significant increase in serum 25(OH)D concentrations (10.9 ± 5.3 vs. 8.2 ± 7.2 ng/mL; p = 0.018), higher corrected dose-response (12.3 ± 5.9 vs. 8.2 ± 7.2 ng/mL increase per 1,000 IU daily; p = 0.002), and a higher proportion of patients attaining 25(OH)D > 20 ng/mL (78.1% vs. 58.3%,; p=0.005) compared with the daily group. No cases of hypercalcemia were observed in either group.

Conclusions

Monthly administration of vitamin D3 may be an effective and safe alternative to correct hypovitaminosis D in pediatric population, possibly attributed to enhanced compliance.

Symptomatic Hypocalcemia due to Nutritional Vitamin D Deficiency in Three Adolescents during the COVID-19 Pandemic

Background

Symptomatic hypocalcemia secondary to vitamin D deficiency (VDD) is rare among adolescents without underlying medical disorders, but its prevalence is higher in known risk populations. We report on three adolescent males with low nutritional intake of vitamin D and calcium and limited sun exposure who presented with hypocalcemic tetany and muscle cramps due to VDD during the COVID-19 pandemic. Case Reports. Three adolescent males (age range 14 to 16 years) presented with symptomatic hypocalcemia: paresthesia, carpopedal spasms, and muscle cramps. All reported limited dairy intake and sun exposure. Laboratory studies showed mean ionized calcium (iCa) 2.73 mg/dl (range 2.69-2.8), mean phosphorus 4.17 mg/dl (range, 3-5.4), mean parathyroid hormone (PTH) 431.67 pg/mL (range, 320-527), and mean 25-hydroxyvitamin D (25(OH)D) 7.37 ng/mL (range 5.3-10.8). All the patients presented during the COVID-19 pandemic, and one had COVID-19 infection. All were treated with oral calcium and high dose ergocalciferol. Patients 2 and 3 were also treated with intravenous calcium gluconate infusion and oral calcitriol.

Conclusion

Severe VDD with symptomatic hypocalcemia can occur among adolescents without underlying medical diagnoses due to dietary and behavioral habits that limit nutritional intake and sun exposure. Risk factors of the patients may have been potentiated by pandemic-related behaviors such as more time indoors at home related to social distancing, as well as diets with limited nutrient intake. Adolescents presenting with nonspecific musculoskeletal symptoms should be screened for VDD and hypocalcemia. Appropriate treatment and preventive measures can stop immediate and long-term complications.

The link between vitamin D, chemerin and metabolic profile in overweight and obese children - preliminary results

Background

Vitamin D affects adipogenesis, oxidative stress, inflammation, secretion of adipocytokines, lipid metabolism and thermogenesis. Some researchers postulate that those effects could be exerted by the influence of vitamin D on chemerin levels.

Aim of the study

We aimed to investigate if there is a link between serum 25-hydroksyvitamin D [25(OH)D], chemerin and metabolic profile in overweight and obese children before and after vitamin D supplementation.

Material and methods

The prospective study included 65 overweight and obese children aged 9.08-17.5 years and 26 peers as a control. None of the patients in the study group had received vitamin D within the last twelve months before the study.

Results

The study group had lower baseline 25(OH)D (p<0.001) and higher chemerin (p<0.001), triglycerides (TG, p<0.001), triglycerides/high density lipoprotein cholesterol (TG/HDL-C, p<0.001), C-reactive protein (CRP, p<0.05), fasting insulin (p<0.001), Homeostasis Model Assessment - Insulin Resistance (HOMA-IR, p<0.001), alanine aminotransferase (ALT, p<0.001) and uric acid (p<0.001) compared to the control group. Baseline vitamin D was related to fasting insulin (R=-0.29, p=0.021), HOMA-IR (R=-0.30, p=0.016), HDL-C (R=0.29, p=0.020) and uric acid (R=-0.28, p=0.037) in the study group. Baseline chemerin was related to insulin at 30' (R=0.27, p=0.030), 60' (R=0.27, p=0.033), 90' (R=0.26, p=0.037) and 120' (R=0.26, p=0.040) during the oral glucose tolerance test (OGTT) and ALT (R=0.25, p=0.041) in the study group. Correlation between vitamin D and chemerin (R=-0.39, p=0.046) was found only in the control group. After six months of vitamin D supplementation a decrease in CRP (p<0.01), total cholesterol (p<0.05), ALT (p<0.01), glucose at 150' OGTT (p<0.05) was observed. Moreover, we noticed a tendency for negative association between 25(OH)D and chemerin levels (p=0.085). Multivariable backward linear regression models were build using baseline vitamin D, baseline chemerin and six months chemerin as the dependent variables.

Conclusions

Our study confirmed that vitamin D has positive effect on metabolic profile in overweight and obese children. The relationship between vitamin D and chemerin is not clear, nevertheless we have observed a tendency to decrease chemerin concentrations after improving vitamin D status, even without a significant reduction in body fat mass.

Screening Questionnaire for Vitamin D Insufficiency in Children with Obesity

Non-invasive screening tools to identify children at high risk of vitamin D (VitD) deficiency are proactive measures in preventive care. Recently, a validated questionnaire (Evaluation dEficieNCy Questionnaire, EVIDENCe-Q) for identifying newly diagnosed VitD-insufficient adults has been developed. We tested the EVIDENCe-Q modified for children with obesity and evaluated the correlation between VitD and questionnaire scores to adapt this tool to the pediatric population. We enrolled 120 children with obesity (BMI ≥ 2). Clinical evaluation and VitD levels were considered. The modified EVIDENCe-Q included information regarding factors affecting control of VitD, with scores ranging between 0 (best) and 36 (worst). VitD and adiposity indices were inversely correlated. The threshold values for identifying severe deficiency (<10 mg/dL), deficiency (<20 mg/dL) and insufficiency (<30 mg/dL) were scores of 21, 19 and 23, respectively. According to those thresholds, the prevalence of severe deficiency, deficiency and insufficiency was 47.5%, 69.2% and 23.3%, respectively; the best accuracy was obtained with a questionnaire score cut-off of 19 for the VitD deficiency level. A novel simple screening tool such as the modified EVIDENCe-Q would be useful in clinical practice to identify potential cases of hypovitaminosis D and select at-risk patients. Considering the limited accuracy and specificity of our results, for the pediatric population a dedicated tool should be created. Phases of childhood and the role of adipose tissue could be considered in the definition of a questionnaire intended for pediatric patients with obesity.

Is There an Association between Vitamin D Concentrations and Overweight in Children and Adolescents?

OBJECTIVE

To describe the 25-hydroxyvitamin D [25(OH)D] concentrations in children and adolescents and to verify the association with the body mass index z-score (ZBMI), lipid profile and Homeostasis Model Assessment-Insulin Resistance (HOMA-IR).

METHOD

Cross-sectional study with 170 children and adolescents aged between 4 and 15 years (106 normal weight and 64 overweight) from a public institution in Santo André-Brazil. Weight, height and waist circumference were verified and ZBMI and waist-to-height ratio (WHtR) were calculated. Biochemical analysis: 25(OH)D levels [deficiency: 25(OH)D < 20 ng/ml]; glycemia and insulin (HOMA-IR), lipid profile and ultra-sensitive C-reactive protein.

RESULTS

Mean age was 8.37 ± 3.17 years; 89 (52.4%) were male; 77 (45.3%) Caucasians and 121 (71.2%) pre-pubescent. Overweight was observed in 64 (37.6%), dyslipidemia in 108 (63.5%) and 25(OH)D deficiency in 117 (68.8%) of the individuals. ZBMI (r = -0.209; p = 0.006), WHtR (r = -0.154; p = 0.045), triglycerides (TGs) (r = -0.161; p = 0.037) and TGs/high-density lipoprotein (HDL) ratio (r = -0.168; p = 0.028) were inversely correlated with 25(OH)D concentrations. Overweight children and adolescents were four times more likely to have vitamin D deficiency (odds ratio = 4.28; 95% confidence interval 1.152 to 4.907; p = 0.019), after adjustment for pubertal development (prepubertal), sex (male), HDL-c (<45 mg/dl), non-HDL (>120 mg/dl), TG/HDL ratio (>2.0) and HOMA-IR.

CONCLUSIONS

A high prevalence of vitamin D deficiency (68.8%) was observed. There was an independent association between vitamin D deficiency and overweight, not observed for dyslipidemia and insulin resistance. The data point to the need for periodic monitoring of serum concentrations of 25(OH)D and reinforcement of guidelines for combating and preventing overweight in the pediatric age group.