Concentration levels of serum 25-Hydroxyvitamin-D and vitamin D deficiency among children and adolescents of India: a descriptive cross-sectional study

Age-, season- and gender-specific reference intervals of serum 25-hydroxyvitamin D3 for healthy children (0 ~ 18 years old) in Nanning area of China

Establishing specific reference intervals (RIs) of serum 25-hydroxyvitamin D3 [25(OH)D] for children is essential for improving the accuracy of diagnosis and prognosis monitoring of diseases such as rickets and growth retardation. The study including 6,627 healthy children was conducted to establish specific RIs of 25(OH)D for children in Nanning area of China. The results showed that there were statistically significant differences among age, season, and gender of serum 25(OH)D levels, and the age-specific RIs of serum 25(OH)D were 20.3 ~ 53.6 ng/mL for 0 ~  ≤ 1 year and 18.9 ~ 49.6 ng/mL for 2 ~  ≤ 3 years. The age-, season-specific RIs of serum 25(OH)D for 4 ~  ≤ 6 years in spring-summer and autumn-winter were 15.8 ~ 42.6 ng/mL and 15.2 ~ 37.7 ng/mL, respectively. The age-, gender-specific RIs of serum 25(OH)D for 7 ~  ≤ 18 years for males and females were 12.1 ~ 36.1 ng/mL and 10.8 ~ 35.3 ng/mL, respectively. This study successfully established the RIs of serum 25(OH)D, which may help to improve disease diagnosis and monitoring for children in the Nanning area of China.

Factors Associated with Vitamin D Deficiency and Their Relative Importance among Indian Adolescents: An Application of Dominance Analysis

Vitamin D deficiency is a serious issue in developing nations, including India. This study investigates the determinants of vitamin D deficiency among Indian adolescents and assesses their relative importance using dominance analysis. Data from the Comprehensive National Nutrition Survey (CNNS) conducted between 2016 and 2018 were utilized in this study. Vitamin D levels were assessed based on serum 25-hydroxyvitamin D concentration, with a sample size encompassing 13,065 adolescents aged between 10 and 19 years. Backward stepwise multivariate logistic regression was used to identify the correlates of vitamin D deficiency, and the relative importance of these factors was assessed using dominance analysis. The study identified nine predictors that were significantly associated with vitamin D deficiency at a 1% level of significance (α = 0.001). Among these factors, sex was found to be the most significant predictor, with female adolescents being 2.66 (95% CI: 95% CI: 2.39-2.96) times more likely to be vitamin D deficient compared to male adolescents. Lifestyle and behavioral factors, such as "sex," "wealth index," and "place of residence," were more dominant in predicting vitamin D deficiency than biological indicators like "BMI" and "serum creatinine." This underscores the vital role of sunlight exposure in maintaining sufficient vitamin D levels. In summary, this study sheds light on the multifaceted factors contributing to vitamin D deficiency among Indian adolescents, emphasizing the significance of targeted interventions and public health awareness campaigns to mitigate this pressing issue.

Knowledge, Attitude, and Practices Regarding Vitamin D in Middle-Aged Pakistani Population and the Impact of Sun Exposure on Their Serum Vitamin D Levels

OBJECTIVE

This study aimed to assess the knowledge, attitude, and practices regarding vitamin D (D-KAP) among middle-aged individuals in Pakistan and examine the impact of sun exposure on their serum vitamin D levels.

METHODOLOGY

A cross-sectional study was conducted, involving 80 middle-aged individuals from Lahore, Pakistan. Data on demographics, sun exposure, and D-KAP were collected. Serum vitamin D levels were measured using enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS

The study revealed inadequate knowledge and awareness of vitamin D among the participants. There was a positive correlation between sun exposure duration and serum vitamin D levels, indicating the importance of sun exposure for maintaining optimal vitamin D status. However, there was no significant difference in practice scores between groups, highlighting the need for interventions to bridge the gap between knowledge and practice.

CONCLUSION

The study emphasizes the need to improve D-KAP in the middle-aged Pakistani population. Public health initiatives should focus on promoting accurate information, addressing cultural beliefs, and encouraging responsible sun exposure practices. Collaborative efforts are crucial to address vitamin D deficiency and its associated health consequences.

Association between serum 25-hydroxyvitamin-D and Triglycerides-Glucose index among Indian adolescents

Background

Vitamin D deficiency has been found to associated with numerous skeletal and non-skeletal diseases including Diabetes Mellitus. Insulin Resistance (IR) is considered as one of the primary reasons of Type-2 Diabetes Mellitus (T2DM). The association between vitamin D deficiency and IR has been extensively explore in previous studies, but none of them focused on Indian adolescents, and none of them used the TyG index as IR marker. Hence, this population-based cross-sectional study investigates the relationship between insulin resistance (IR) assessed using the Triglycerides Glucose Index (TyG index) and vitamin D measured by serum 25-hydroxyvitamin-D (25(OH)D).

Methods

For this study, we utilized data from the Comprehensive National Nutrition Survey (CNNS, 2016–18). The study is based on a sample size of 10,167 adolescents aged 10–19 years. The TyG index cut-off value of 4.65 was used to classify IR. We examined associations between the TyG index and serum 25(OH)D using multiple linear regression models adjusted for potential confounders. Odds of Insulin Resistance among vitamin D deficient/insufficient adolescents were assessed using multivariable logistic regression.

Results

A significant negative association was found between serum 25(OH)D and the TyG index, where a 10% increase in serum 25(OH)D was associated with 0.56 (95% CI = -0.67, -0.45) unit decrement in the TyG index. The odds of having IR were 90% higher among vitamin D deficient adolescents (OR: 1.90; 95% CI = 1.62—2.23) compared to adolescents with adequate levels of vitamin D. The association between vitamin D deficiency and IR was independent of sex; in other words, the association between vitamin D and IR was significant in both the sexes.

Conclusion

Independent of sex, this study found a significant inverse association between vitamin D and insulin resistance in Indian adolescents. The findings of this study highlight the utility of TyG index and the importance of vitamin D in lowering the risk of T2DM in future generations of the country.

Association Between Vitamin D Level and Neonatal Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

In recent years, vitamin D in the occurrence of lung diseases has gradually become a hot topic. Although the role of vitamin D in normal lung development has been confirmed, the correlation between vitamin D level and neonatal respiratory distress syndrome (NRDS) is not clear.

OBJECTIVE

To evaluate the association between vitamin D level and NRDS.

METHODS

We performed a comprehensive search of the following electronic databases: PubMed, Embase, Cochrane Library, Web of Science, and China National Knowledge Infrastructure (CNKI). Literature screening and quality assessment were performed according to inclusion and exclusion criteria. The Newcastle-Ottawa Scale was used to assess the methodological components of each study, and Stata 15.1 software to perform the Meta-analysis.

RESULTS

A total of nine case-control studies were included, with 653 infants with NRDS and 501 infants without NRDS. The Meta-analysis showed no heterogeneity across all studies(I²=0.0%, P=0.583). The fixed-effect model showed that 25 hydroxy vitamin D level of children in the NRDS group was significantly lower than that of the non-NRDS group(SMD = -0.51, 95%CI: -0.63 to -0.39, p ≤ 0.05).

CONCLUSION

This systematic review and meta-analysis study suggests that vitamin D deficiency is very likely to be a high-risk factor of NRDS, and reasonable vitamin D supplementation during pregnancy and after birth is of great significance.