High dietary calcium intake and low adiposity: findings from a longitudinal study in Brazilian adolescents

Calcium, Phosphate, and Vitamin D in Children and Adolescents with Chronic Diseases: A Cross-Sectional Study

Chronic diseases may affect the nutritional status of children and adolescents. Calcium (Ca), phosphorus (P), and vitamin D (Vit-D) are crucial nutrients for their growth and development. Proper diagnosis and treatment are critical components of personalized and precision medicine. Hence, we conducted a cross-sectional and comparative study to evaluate Ca, P, and Vit-D levels in their non-skeletal functions and their association with health and nutritional biomarkers in children and adolescents with diverse chronic conditions. We performed anthropometric, body composition, clinical evaluation, biochemical analysis, and dietary survey methods. A total of 78 patients (1-19 years, 43 females, 42 children) took part in this study. Overall, 24, 30, and 24 participants were obese, undernourished, and eutrophic, respectively. Results found that 74% and 35% of individuals had deficient Vit-D and Ca intake, respectively. Most cases were normocalcemic. Results also found that 47% of the subjects had Vit-D deficiency (VDD), 37% were insufficient, and 37% had hypophosphatemia. Of the 46% and 31% of patients with VDD and insufficient levels, 19% and 11% were hypophosphatemic, respectively. Calcium, P, and Vit-D levels were associated with anthropometric parameters, body mass index, body composition, physical activity, diet, growth hormones, and the immune, liver, and kidney systems. These results show the coincident risk of altered Ca, P, and Vit-D metabolism in children and adolescents with chronic diseases.

Dietary calcium is inversely associated with hepatitis B virus infection: an analysis of US National Health and Nutrition Examination Survey (NHANES) 2007-2020

BACKGROUND

There have been studies on the relationship between hepatitis B virus (HBV) infection and diet. We hypothesized HBV infection is related to dietary calcium intake, but the evidence is limited. This study aimed to examine whether dietary calcium intake is independently related to HBV infection in the United States population.

METHODS

A total of 20,488 participants aged over 20 years from the National Health and Nutrition Examination Survey (NHANES), conducted from 2007 to 2020, were included in this study. Pearson correlation was used to test the association between dietary calcium and serum calcium. The relationships of HBV infection with dietary calcium and serum calcium were assessed by logistic regression models.

RESULTS

There was a weak correlation between dietary calcium and serum calcium (r = 0.048). Logistic regression models indicated that HBV infection had a linear negative correlation with dietary calcium (OR 0.37; 95%CI 0.19, 0.76). For each additional 10 mg dietary calcium, the possibility of HBV infection was reduced by 63%. Hepatitis B positive participants had lower serum calcium content than negative participants. Stratified analysis shown the linear relationship between calcium and HBV infection varied among sex, race/ethnicity, and body mass index.

CONCLUSION

Our findings demonstrated HBV infection was linearly and inversely correlated with dietary calcium. The current study is expected to offer a fresh perspective on reducing HBV infection.

Calcium plus vitamin D supplementation during pregnancy reduces postpartum fat mass in adolescents: A randomized trial

BACKGROUND

Pregnancy during adolescence may increase the risk of overweight/obesity. There is evidence that increasing calcium intake, alone or vitamin D-combined, may favor loss of weight and/or fat mass.

OBJECTIVES

We hypothesized that calcium supplementation during pregnancy reduces excessive fat accumulation during postpartum period. We aimed to investigate the effect of calcium plus vitamin D supplementation during pregnancy on body composition measurements throughout 1 year postpartum in Brazilian adolescents with habitually low calcium intake (~600 mg/day).

METHODS

Adolescents (14-19 years) were randomly assigned to receive a daily supplement (600 mg of calcium plus 200 UI of cholecalciferol, n = 30) or a placebo (n = 26) from 26 weeks of gestation until parturition. Body composition was determined at 5, 20, and 56 weeks postpartum by dual-energy x-ray absorptiometry. The effects of intervention group, time point, as well as their interaction were assessed using repeated measures mixed-effects models.

RESULTS

In the adjusted analysis, those supplemented showed lower total body mass [mean difference = -3.32 kg; confidence interval (CI) 95% -6.12 to -0.52 kg], trunk (-1.25 kg; CI 95% -2.34 to -0.15 kg), android (-0.29 kg; CI 95% -0.53 to -0.04 kg) and subcutaneous (-0.23 kg; CI 95% -0.43 to -0.03 kg) fat masses. In the supplemented group, BMI and postpartum weight retention significantly decreased from 5 to 20 weeks (-0.90 kg/m2 and -1.76 kg, respectively; p < .05). At 56 weeks, BMI was still lower (-1.22 kg/m2 ; p < .05) than 5 weeks.

CONCLUSIONS

Our findings suggest that increasing calcium intake through supplementation in combination with vitamin D contributes to a more pronounced reduction in total body mass overtime, mostly as a consequence of fat mass reductions in central body regions. This trial was registered at clinicaltrials.gov as NCT01732328.