Vitamin D and adolescent health

Association between Blood Vitamin D Levels and Regular Physical Activity in Korean Adolescents

This study aimed to investigate the relationship between vitamin D levels and physical activity in adolescents using data from the Korea National Health and Nutrition Survey (KNHANES). The serum vitamin D concentrations were measured between 2008 and 2014 and analyzed. Adolescents aged 13 to 18 years comprised 4527 of the 61,370 participants surveyed. A final dataset including 2811 adolescents was obtained after those with missing data were excluded. Those who did not participate or only participated in 1−3 days of intense physical activity (p < 0.001), moderate physical activity (p = 0.002), and muscular exercise (weight training) (p < 0.001) showed a higher level of vitamin D deficiency than those who performed the same activities 4−7 days per week. Our results showed that most of the adolescents (76%) were vitamin D-deficient, and the risk was higher among high school than middle school students (odds ratio (OR) = 1.70, 95% confidence interval (CI) = 1.40−2.06; p < 0.001) and higher in girls than boys (OR = 1.43, 95% CI = 1.18−1.72; p < 0.001). Reduced participation in physical activity was correlated with vitamin D deficiency. Furthermore, vitamin D deficiency was associated with a lower frequency of participation in all forms of physical activity, and the association increased significantly with an increase in body mass index.

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.

Prevalence and Risk Factors for Hypovitaminosis D among Healthy Adolescents in Kota Bharu, Kelantan

OBJECTIVE

We aim to study the prevalence and risk factors of hypovitaminosis D among healthy adolescents in Kota Bharu, Kelantan based on the most recent Paediatric Consensus guideline.

METHODOLOGY

Ten public schools were selected from Kota Bharu, Kelantan. We analysed their demography (age, gender, ethnicity, income), measured their anthropometry (height, weight, BMI) and finally analysed their vitamin D and intactParathyroid hormone levels.

RESULTS

The prevalence of hypovitaminosis D was 16.9% among healthy teenagers with mean age of 15.9±1.39 years. Multivariate analysis showed female gender (adjusted OR, 95% CI): 23.7 (5.64, 100.3) and Chinese 0.24 (0.07, 0.84) were the significant predictors for hypovitaminosis D.

CONCLUSION

The prevalence of healthy adolescents with hypovitaminosis D in Kota Bharu, Kelantan was 16.9% using the most recent cut off value of 30 nmol/L from the global consensus 2016. Female and Malay were the significant risk factors associated with hypovitaminosis D. Higher cut off value would result in overestimation of prevalence rate of hypovitaminosis D.

Transcriptional activity of vitamin D receptor in human periodontal ligament cells is diminished under inflammatory conditions

Background

Although vitamin D₃ deficiency is considered as a risk factor for periodontitis, supplementation during periodontal treatment has not been shown to be beneficial to date. Human periodontal ligament cells (hPDLCs) are regulated by vitamin D₃ and play a fundamental role in periodontal tissue homeostasis and inflammatory response in periodontitis. The aim of this study is to investigate possible alterations of the vitamin D₃ activity in hPDLCs under inflammatory conditions.

Methods

Cells isolated from six different donors were treated with either 1,25(OH)₂D₃ (0 to 10 nM) or 25(OH)D₃ (0 to 100 nM) in the presence and absence of ultrapure or standard Porphyromonas gingivalis lipopolysaccharide (PgLPS), Pam3CSK4, or interferon‐γ for 48 hours. Additionally, nuclear factor (NF)‐κB inhibition was performed with BAY 11‐7082. The bioactivity of vitamin D in hPDLCs was assessed based on the gene expression levels of vitamin D receptor (VDR)‐regulated genes osteocalcin and osteopontin. Additionally, VDR and CYP27B1 expression levels were measured.

Results

The vitamin D₃‐induced increase of osteocalcin and osteopontin expression was significantly decreased in the presence of standard PgLPS and Pam3CSK4, which was not observed by ultrapure PgLPS. Interferon‐y had diverse effects on the response of hPDLCs to vitamin D₃ metabolites. NF‐kB inhibition abolished the effects of standard PgLPS and Pam3CSK4. Standard PgLPS and Pam3CSK4 increased VDR expression in the presence of vitamin D₃. CYP27B1 expression was not affected by vitamin D₃ and inflammatory conditions.

Conclusions

This study indicates that the transcriptional activity of VDR is diminished under inflammatory conditions, which might mitigate the effectiveness of vitamin D₃ supplementation during periodontal treatment.

A systematic review and meta-analysis of prevalence of vitamin D deficiency among adolescent girls in selected Indian states

BACKGROUND:

Vitamin D deficiency among adolescents is an emerging public health priority as adolescence marks a period of rapid growth and the onset of the reproductive phase. However, lack of national prevalence data and intervention strategies is of public health concern.

OBJECTIVE:

The objective of this study was to determine the pooled prevalence of vitamin D deficiency among adolescent girls in selected Indian states.

METHODS:

A systematic literature review was performed using three different search engines. The searches yielded nine eligible articles. Study quality was assessed for 10 different criteria. Meta-analysis was performed to estimate pooled prevalence of vitamin D deficiency among adolescent girls and to assess the heterogeneity among selected studies.

RESULTS:

A sample of n=1352 was used to study prevalence among adolescent girls. The random effects combined estimate for overall prevalence was 25.70% (95% CI 3.89-2137.9). High heterogeneity (tau²=1.71, I²=100%) was observed and seven out of nine studies showed low to moderate risk and two showed high risk of bias. The test for overall effect was observed to be Z=0.77 ( p=0.44).

CONCLUSIONS:

High prevalence of vitamin D deficiency among adolescent girls identifies the need to introduce screening of adolescents and introduce proven public-health interventions such as fortification of foods to address deficiency.

[Prevalence of hypovitaminosis D and associated factors in Spanish population of school children and adolescents]

Objetivo

Analizar la prevalencia de hipovitaminosis D y factores asociados en escolares y adolescentes residentes en una región del norte peninsular.

Diseño

Estudio descriptivo transversal (muestreo de conveniencia).

Emplazamiento

Atención primaria.

Participantes

Fueron incluidos 602 sujetos sanos de raza caucásica con edades comprendidas entre 3,1 y 15,4 años.

Mediciones principales

Se ha calculado la prevalencia de hipovitaminosis D (variable dependiente) según los criterios de la US Endocrine Society: deficiencia (calcidiol < 20 ng/ml), insuficiencia (calcidiol: 20-29 ng/ml) y suficiencia (calcidiol ≥ 30 ng/ml). Se han registrado como variables independientes: sexo, edad, índice de masa corporal, lugar de residencia y estación del año, analizándose su asociación con la hipovitaminosis D mediante regresión logística múltiple.

Resultados

La prevalencia de hipovitaminosis D era del 60,4% (insuficiencia: 44,6%; deficiencia: 15,8%). Las variables asociadas con la hipovitaminosis D eran el sexo femenino (OR: 1,6; IC 95%: 1,1-2,3), la edad puberal (OR: 1,8; IC 95%: 1,2-2,6), las estaciones de otoño (OR: 9,5; IC 95%: 4,8-18,7), invierno (OR: 8,8; IC 95%: 4,5-17,5) y primavera (OR: 13,2; IC 95%: 6,4-27,5), el entorno urbano (OR:1,6; IC 95%: 1,1-2,2) y la obesidad severa (OR: 4,4; IC 95%: 1,9-10,3).

Conclusiones

En la población infantojuvenil existe una alta prevalencia de hipovitaminosis D, y los factores asociados son el sexo femenino, la edad puberal, el otoño, el invierno y la primavera, la obesidad severa y el entorno urbano. Habría que considerar la necesidad de administrar suplementos vitamínicos o ingerir mayores cantidades de sus fuentes dietéticas naturales y/o alimentos enriquecidos durante los meses de otoño, invierno y primavera.

Effect of a program of short bouts of exercise on bone health in adolescents involved in different sports: the PRO-BONE study protocol

BACKGROUND

Osteoporosis is a skeletal disease associated with high morbidity, mortality and increased economic costs. Early prevention during adolescence appears to be one of the most beneficial practices. Exercise is an effective approach for developing bone mass during puberty, but some sports may have a positive or negative impact on bone mass accrual. Plyometric jump training has been suggested as a type of exercise that can augment bone, but its effects on adolescent bone mass have not been rigorously assessed. The aims of the PRO-BONE study are to: 1) longitudinally assess bone health and its metabolism in adolescents engaged in osteogenic (football), non-osteogenic (cycling and swimming) sports and in a control group, and 2) examine the effect of a 9 month plyometric jump training programme on bone related outcomes in the sport groups.

METHODS/DESIGN

This study will recruit 105 males aged 12-14 years who have participated in sport specific training for at least 3 hours per week during the last 3 years in the following sports groups: football (n = 30), cycling (n = 30) and swimming (n = 30). An age-matched control group (n = 15) that does not engage in these sports more than 3 hours per week will also be recruited. Participants will be measured on 5 occasions: 1) at baseline; 2) after 12 months of sport specific training where each sport group will be randomly allocated into two sub-groups: intervention group (sport + plyometric jump training) and sport group (sport only); 3) exactly after the 9 months of intervention; 4) 6 months following the intervention; 5) 12 months following the intervention. Body composition (dual energy X-ray absorptiometry, air displacement plethysmography and bioelectrical impedance), bone stiffness index (ultrasounds), physical activity (accelerometers), diet (24 h recall questionnaire), pubertal maturation (Tanner stage), physical fitness (cardiorespiratory and muscular), bone turnover markers and vitamin D will be measured at each visit.

DISCUSSION

The PRO-BONE study is designed to investigate the impact of osteogenic and non-osteogenic sports on bone development in adolescent males during puberty, and how a plyometric jump training programme is associated with body composition parameters.

First-trimester maternal serum 25-hydroxyvitamin D₃ status and pregnancy outcome

OBJECTIVE

To determine the pregnancy outcome as a function of the first-trimester serum 25-hydroxyvitamin D(3) [25(OH)D] status and to compare the 25(OH)D levels in the first and third trimesters.

METHODS

Pregnant women (n=466) tested for serum 25(OH)D levels during the first trimester were followed up until the end of pregnancy, and the obstetric and neonatal outcomes were compared in reference to the baseline 25(OH)D status. The third-trimester 25(OH)D levels were additionally measured in a subset of women (n=148).

RESULTS

The obstetric and neonatal outcomes did not vary as a function of the first-trimester 25(OH)D status. Neither did the 25(OH)D levels vary as a function of pregnancy outcomes. Overall, the 25(OH)D levels significantly decreased from the first to the third trimester. The first- and third-trimester 25(OH)D levels of samples initially taken during autumn/winter were significantly lower than those that were initially taken during spring/summer. Interestingly, the decrease in 25(OH)D levels during the third trimester was independent of the season of sampling.

CONCLUSION

The pregnancy outcome was independent of the first-trimester 25(OH)D status. Overall, the 25(OH)D levels significantly decreased in the third trimester. More research in this area is warranted.

Vitamin D and aging: beyond calcium and bone metabolism

BACKGROUND

Low serum 25-hydroxyvitamin D (25[OH]D) levels are common and may be associated with morbidity and mortality (and indeed with frailty more generally). This association is not restricted to the links between vitamin D and calcium and bone metabolism.

OBJECTIVE

To review the influences of vitamin D on the aging process other than those related to bone and calcium. Its effect on mortality is also assessed.

METHODS

The PubMed database was searched for English-language articles relating to vitamin D, using the following MeSH terms: vitamin D, mortality, cardiovascular diseases, and frailty. In addition, searches were carried out with Google.

RESULTS

Although some of the reported results have proved controversial, overall the evidence seems to support an association between low serum 25[OH]D levels and mortality rates (all-cause and cardiovascular). Frailty is a condition frequently associated with low serum 25[OH]D levels.

CONCLUSION

The aging process and mortality are associated with low vitamin D levels. Prospective controlled trials are warranted to determine whether vitamin D supplements can increase longevity and reduce the incidence of certain conditions.