Vitamin D status and blood pressure in children and adolescents: a systematic review of observational studies

Vitamin D and its associations with blood pressure in the Chronic Kidney Disease in Children (CKiD) cohort

BACKGROUND

Vitamin D (25OHD) can modulate pathways and mechanisms that regulate blood pressure (BP). Observational studies in children and adults have shown an inverse association between 25OHD and BP. Studies evaluating associations between 25OHD and BP in pediatric chronic kidney disease are limited.

METHODS

We evaluated the associations between 25OHD and BP using data from the Chronic Kidney Disease in Children (CKiD) study. Clinic or ambulatory BP index was defined as participant's BP divided by 95th age-sex-height-specific BP percentile, an index > 1 suggests hypertension. Primary outcomes of interest were changes in systolic and diastolic clinic and ambulatory BP indices over follow-up. Linear mixed-effects models were used to evaluate associations between BP indices and 25OHD.

RESULTS

The study cohort consisted of 370 participants who contributed 970 person-visits. A subset of 194 participants with ambulatory BP data contributed 465 person-visits. There was an association between baseline 25OHD levels and clinic systolic BP index such that for every 10 ng/ml lower 25OHD, clinic systolic BP index was 1.0% higher (95%CI: 0.2-1.8, p = 0.016) between participants. The association between clinic diastolic BP index with baseline 25OHD was not significant. For within-person changes, longitudinal decreases in 25OHD were not significantly associated with concomitant increases in clinic systolic or diastolic BP index. There were no significant associations between 25OHD levels at baseline or longitudinally with 24-h ABPM indices.

CONCLUSIONS

Low 25OHD levels were associated with higher clinic systolic BP in children with CKD. Vitamin D supplementation to maintain normal 25OHD levels might be a useful adjunctive treatment in optimizing BP control in these high-risk patients.

Low socioeconomic status predicts vitamin D status in a cross-section of Irish children

Vitamin D is essential for bone and muscle health with adequate status in childhood crucial for normal skeletal development. We aimed to investigate vitamin D status in a convenience sample (n = 1226) of Irish children (aged 1-17 years) who had serum 25-hydroxyvitamin D (25(OH)D) tested by request of their GP at a Dublin Hospital between 2014 and 2020. We examined predictors including age, sex, season and socioeconomic status (SES). Vitamin D deficiency (<30 nmol/l) was prevalent affecting 23 % and was more common in disadvantaged areas (34 %) and in those aged >12 v. ≤12 years (24 % v. 16 %, P = 0⋅033). The greatest predictor was SES (disadvantaged v. affluent, OR 2⋅18, CI 1⋅34, 3⋅53, P = 0⋅002), followed by female sex (OR 1⋅57, CI 1⋅15, 2⋅14, P = 0⋅005) and winter season (October to February, OR 1⋅40, CI 1⋅07, 1⋅84, P = 0⋅015). A quarter of our sample of children were deficient, rising to one-third in those in disadvantaged areas. Females and those aged over 12 years had a higher prevalence of deficiency. Public health strategies to improve vitamin D status in Irish children, including systematic food fortification may need to be considered to address this issue.

Serum 25-Hydroxyvitamin D correlates with systolic blood pressure in obese male schoolchildren

INTRODUCTION

Childhood obesity is associated with an increased risk of chronic diseases. We aimed to examine the relation between serum levels of 25-hydroxyvitamin D (25[OH]D) and blood pressure in obese schoolchildren.

MATERIAL AND METHODS

Cross-sectional study in school-age children with obesity. The serum levels of 25(OH)D were measured and classified as sufficient or insufficient/deficient. Blood pressure was measured. Normal values were considered <90th percentile, elevated blood pressure ≥90th to <95th percentiles, and hypertension ≥95th percentile, according to blood pressure reference tables, specific for age, sex, and height. The Pearson correlation was performed.

RESULTS

256 obese schoolchildren (123 [48.0%] females and 133 [51.9 %] males) were evaluated. The prevalence rates of vitamin D deficiency, insufficiency, and sufficiency were 23.4%, 52.3%, and 24.2%, respectively. Normal blood pressure was observed in 101 (39.4%) children; the frequencies of elevated blood pressure and hypertension were 10.9% and 49.6%, respectively. A moderate inverse correlation of 25(OH) D levels with systolic blood pressure levels (r = -0.54, p = 0.03) was observed. When analyzed by sex, a significantly high inverse correlation between 25(OH)D levels and systolic blood pressure was observed in males (r=-0.85 and p=<0.001). No significant correlation was found in females (systolic r=-0.16 and p=0.67; diastolic r= -0.15 and p=0.812). When performing the multiple regression analysis, the 25(OH)D levels and body mass index (BMI) were the significant predictors for systolic blood pressure.

CONCLUSIONS

We identified an inverse correlation between 25[OH]D levels and systolic blood pressure in male schoolchildren with obesity.

Dietary Magnesium Intake Modifies the Association Between Vitamin D and Systolic Blood Pressure: Results From NHANES 2007–2014

Introduction

Although the association between blood pressure and vitamin D has been well studied, the effects of dietary magnesium intake on this relationship are still unclear. Thus, this study aimed to determine the effects of dietary magnesium intake on the association between vitamin D and blood pressure.

Methods

The present study analyzed data from the continuous the National Health and Nutrition Examination Survey (NHANES) 2007–2014. We included 8,799 participants aged 20 years or older. Multivariable linear regression was performed to assess the association between vitamin D and systolic blood pressure (SBP) and diastolic blood pressure (DBP). Dietary magnesium intake was stratified by low magnesium intake (<299 mg/d) and high magnesium intake (≥299 mg/d). Effect modification by dietary magnesium intake was assessed through interaction tests between vitamin D and SBP in the multivariable linear regression.

Results

In this cross-sectional study, we found that vitamin D was negatively related to SBP, but not to DBP. The relationship between vitamin D and SBP was different in the low and high magnesium intake group (β: −0.25 95%Cl: −0.4~0.07 vs β: −0.32 95%Cl: −0.52~-0.12). Furthermore, magnesium intake significantly modified the negative relationship between vitamin D and SBP in most of the models.

Conclusion

Our research showed that magnesium and vitamin D have an interactive effect in reducing SBP, which may have great importance for clinical medication.