Relationship between 25(OH)D levels and circulating lipids in African American adolescents

Vitamin D levels and lipid profile in children and adolescents: a tight correlation

INTRODUCTION

Vitamin D is an essential hormone for humans, playing an important role in musculoskeletal and calcium homeostasis. Its deficiency/insufficiency seems to contribute to the development of cardiometabolic diseases in adults: this correlation appears less clear for children and adolescents. The aim of this paper was to review literature data on the relationship between vitamin D and lipid profile alterations in pediatric population.

EVIDENCE ACQUISITION

We carried out a comprehensive research in electronic databases, including MEDLINE and PubMed up to December 2022, for cross-sectional or prospective studies that investigated the correlation between serum vitamin D levels and lipid profile in children and adolescents. At the end of the process, 37 articles were included in this review.

EVIDENCE SYNTHESIS

According to our findings, vitamin D deficiency/insufficiency is strongly associated with lower high-density lipoprotein (HDL) cholesterol levels and higher levels of triglycerides and total cholesterol. Data about low-density lipoproteins (LDL) cholesterol are inconsistent. The potential role of vitamin D supplements for the prevention of cardiometabolic disease currently remains a speculation.

CONCLUSIONS

An increasing number of studies shows how hypovitaminosis D in the pediatric age may play a role in the pathogenesis of metabolic disorders and lipid profile alterations. Data regarding the potential role of vitamin D supplements for the prevention of cardiometabolic disease are currently controversial. Further studies are needed to evaluate the causality of this association and to assess the underlying pathogenetic mechanisms.

Vitamin D deficiency and cardiometabolic risk factors in adolescents: systematic review and meta-analysis

Vitamin D deficiency is associated with an increase in the occurrence of cardiometabolic events, but the evidence of this relationship in adolescence is still limited. Thus, we analyzed the association between vitamin D deficiency and cardiometabolic risk factors in adolescents. Observational studies were searching in PubMed/Medline, Embase, Scopus, Web of Science, Science Direct, Lilacs, and Google Scholar database. Random effects models were used to summarize standardized mean differences for as a summary measure. The certainty of the evidence was verified using the Cochrane recommendations. A total of 7537 studies were identified, of which 32 were included in the systematic review and 24 in the meta-analysis.Vitamin D deficiency was associated with increased systolic pressure (SMD = 0.22; 95%CI = 0.10; 0.34), diastolic pressure (SMD = 0.23; 95%CI = 0.10; 0.35), glycemia (SMD = 0.13; 95%CI = 0.05; 0.12), and insulin (SMD = 0.50; 95%CI = 0.15; 0.84), an increase in the HOMA index (SMD = 0.48; 95%CI = 0.36; 0.60), high triglyceride values (SMD = 0.30; 95%CI = 0.11; 0.49), and reduced HDL concentrations (SMD= -0.25; 95%CI = -0.46; -0.04). No statistically significant association was observed for glycated hemoglobin, LDL cholesterol, and total cholesterol. Most of the studies presented low and moderate risks of bias, respectively. The certainty of the evidence was very low for all the outcomes analyzed. Vitamin D deficiency was associated with increased exposure to the factors linked to the occurrence of cardiometabolic diseases in adolescents. Systematic Review Registration: PROSPERO (record number 42,018,086,298).

The relationship between vitamin D levels in umbilical cord blood and infantile eczema

A total of 179 normal full-term pregnant women and their newborns were randomly selected. Umbilical venous blood was extracted after the delivery, and the serum level of 25(OH)D3 was measured. Forty 2 days, 3 months, 6 months, and one year after the birth to be asked about the occurrence and development of infant eczema. Thirteen cases were lost to follow-up. The median concentration of 25(OH)D3 in the cord blood was 25.40 ng/mL. Thirty eight cases (22.9%) were vitamin D deficient (<20 ng/mL), 77 cases (46.4%) were vitamin D insufficient (20-30 ng/mL), and 51 cases (30.7%) were vitamin D sufficient (≥30 ng/mL). The incidence of eczema in the umbilical cord blood vitamin D sufficient group was lower than that in the deficient and insufficient groups (p < .05). Sufficient umbilical cord blood vitamin D levels are associated with a lower incidence of eczema in infants up to one year of age. IMPACT STATEMENTWhat is already known on this subject? A number of studies have suggested that vitamin D levels in early life are related to the occurrence of allergic diseases, but the conclusions are not uniform.What do the results of this study add? The rate of sufficient umbilical cord blood vitamin D was low in the Songjiang area of Shanghai. Sufficient umbilical cord blood vitamin D levels (≥30 ng/mL) are associated with a lower incidence of eczema in infants up to 1 year of age.What are the implications of these findings for clinical practice and/or further research? At present, the dose of vitamin D for pregnant women at home and abroad is not consistent, so the specific dose of vitamin D for pregnant women to maintain the foetus needs further discussion. It is expected that a reasonable recommended dose can be developed to reduce the risk of allergic diseases in future generations from a primary prevention perspective.

Vitamin D deficiency and cardiovascular risk in type 2 diabetes population

This study aims to assess vitamin D deficiency-induced dyslipidemia and cardiovascular disease (CVD) risk in poor glycemic control among type 2 diabetes mellitus (T2DM) patients. This study was carried out among 455 T2DM patients involving poor glycemic control (n = 247) and good glycemic control (n = 208). Fasting plasma glucose (FPG) and HbA1c were measured to assess glycemic control. Cardiac risk ratio, atherogenic index plasma, and atherogenic coefficient were calculated to assess and compare the CVD risk in different groups. Patients with poor control had a significantly higher level of total cholesterol (TC), triglyceride (TG), and non-high-density lipoprotein lipase cholesterol (non-HDL-C), atherogenic variables, and lower level of high-density lipoprotein lipase cholesterol (HDL-C) as compared to patients with good glycemic control. We also observed significant negative correlation of vitamin D with lipid markers and atherogenic variables in poor glycemic control diabetic population. The serum vitamin D levels were inversely associated with HbA1c, FPG, TG, TC, and non-HDL-C. Furthermore, hypercholesterolemia, hypertriglyceridemia, and elevated non-HDL-C were the independent risks in hypovitaminosis D population. Vitamin D deficiency in poor glycemic control is likely to develop dyslipidemia as compared to vitamin D insufficient and sufficient groups. Thus, vitamin D supplementation and an increase in exposure to sunlight may reduce the risk of cardiovascular complications in diabetes.

Lipid profile of childhood cancer survivors and the effects of vitamin D supplementation: a prospective study

Background

Childhood cancer survivors (CCS) have high prevalence of obesity vitamin D (VD) deficiency together with dyslipidemia. We aimed to evaluate lipid profile and the effect of VD supplementation in CCS.

Results

VD deficiency was more frequent among obese CCS and their lipid profiles, TC, and LDL-C levels were significantly higher compared to non-obese patients. After VD supplementation trials, VD levels increased among obese and non-obese children albeit it was significantly higher in non-obese subjects while the lipid profile of obese patients significantly decreased. Also, parathyroid hormone levels were persistently elevated among VD-deficient obese patients. Yet, the weight of obese patients remained unchanged.

Conclusion

VD deficiency was more prevalent among obese CCS. VD supplementation helped in normalization of the lipid profile of obese CCS. Regular measurement of PTH and 25OH-VD is recommended for CCS especially obese ones who may need VD supplementation.

Treatment with Vitamin D3 in Vitamin D Deficient Adolescents: A Pilot Study

Multiple epidemiological studies have shown that vitamin D deficiency is highly prevalent amongst adolescents in the USA. However, recommendations regarding the treatment of vitamin D deficiency in healthy adolescents are not well defined. We carried out a prospective pilot study, to determine whether treatment with 2000 international units of vitamin D3 daily for 3 months, would normalize the vitamin D levels in vitamin D deficient adolescents. Following treatment there was a 56.02% increase in the vitamin D levels from the mean baseline values and 80.39% of the subjects normalized their vitamin D levels. There were no adverse effects associated with this intervention. This study offers complementary guidelines to the existing recommendations from the American Academy of Pediatrics on the optimal dose and duration of vitamin D3 therapy in vitamin D deficient, but otherwise healthy adolescents. Further prospective, large scale, case control studies are indicated to validate our results.

Vitamin D Regulation of the Uridine Phosphorylase 1 Gene and Uridine-Induced DNA Damage in Colon in African Americans and European Americans

BACKGROUND & AIMS

African Americans have the greatest colorectal cancer (CRC) burden in the United States; interethnic differences in protective effects of vitamin D might contribute to disparities. 1α,25(OH)₂D₃ vitamin D (the active form of vitamin D) induces transcription of the uridine phosphorylase gene (UPP1) in colon tissues of European Americans but to a lesser extent in colon tissues of African Americans. UPP1-knockout mice have increased intestinal concentrations of uridine and Deoxyuridine triphosphate (dUTP), have increased uridine-induced DNA damage, and develop colon tumors. We studied 1α,25(OH)₂D₃ regulation of UPP1 and uridine-induced DNA damage in the colon and differences in these processes between African and European Americans.

METHODS

We quantified expression and activity of UPP1 in response to 1α,25(OH)₂D₃ in young adult mouse colonic cells, human CRC cells (LS174T), and organoids (derived from rectosigmoid biopsy samples of healthy individuals undergoing colonoscopies) using quantitative polymerase chain reaction, immunoblot, and immunocytochemistry assays. Binding of the vitamin D receptor to UPP1 was tested by chromatin immunoprecipitation. Uridine-induced DNA damage was measured by fragment-length analysis in repair enzyme assays. Allele-specific 1α,25(OH)₂D₃ responses were tested using luciferase assays.

RESULTS

Vitamin D increased levels of UPP1 mRNA, protein, and enzymatic activity and increased vitamin D receptor binding to the UPP1 promoter in young adult mouse colonic cells, LS174T cells, and organoids. 1α,25(OH)₂D₃ significantly reduced levels of uridine and uridine-induced DNA damage in these cells, which required UPP1 expression. Organoids derived from colon tissues of African Americans expressed lower levels of UPP1 after exposure to 1α,25(OH)₂D₃ and had increased uridine-induced DNA damage compared with organoids derived from tissues of European Americans. Luciferase assays with the T allele of single nucleotide polymorphism rs28605337 near UPP1, which is found more frequently in African Americans than European Americans, expressed lower levels of UPP1 after exposure to 1α,25(OH)₂D₃ than assays without this variant.

CONCLUSIONS

We found vitamin D to increase expression of UPP1, leading to reduce uridine-induced DNA damage, in colon cells and organoids. A polymorphism in UPP1 found more frequently in African Americans than European Americans reduced UPP1 expression upon cell exposure to 1α,25(OH)₂D₃. Differences in expression of UPP1 in response to vitamin D could contribute to the increased risk of CRC in African Americans.

Winter Cholecalciferol Supplementation at 51°N Has No Effect on Markers of Cardiometabolic Risk in Healthy Adolescents Aged 14-18 Years

Background

Epidemiologic studies have supported inverse associations between low serum 25-hydroxyvitamin D [25(OH)D] and cardiometabolic risk markers, but few randomized trials have investigated the effect of vitamin D supplementation on these markers in adolescents.

Objective

The objective of this study was to investigate the effect of winter-time cholecalciferol (vitamin D3) supplementation on cardiometabolic risk markers in white, healthy 14- to 18-y-old adolescents in the UK (51°N) as part of the ODIN Project.

Methods

In a dose-response trial, 110 adolescents (mean ± SD age: 15.9 ± 1.4 y; 43% male; 81% normal weight) were randomly assigned to receive 0, 10 or 20 μg/d vitamin D3 for 20 wk (October-March). Cardiometabolic risk markers including BMI-for-age z score (BMIz), waist circumference, systolic and diastolic blood pressure, fasting plasma triglycerides, cholesterol (total, HDL, LDL, and total:HDL), and glucose were measured at baseline and endpoint as secondary outcomes, together with serum 25(OH)D. Intervention effects were evaluated in linear regression models as between-group differences at endpoint, adjusted for the baseline value of the outcome variable and additionally for age, sex, Tanner stage, BMIz, and baseline serum 25(OH)D.

Results

Mean ± SD baseline serum 25(OH)D was 49.1 ± 12.3 nmol/L and differed between groups at endpoint with concentrations of 30.7 ± 8.6, 56.6 ± 12.4, and 63.9 ± 10.6 nmol/L in the 0, 10, and 20 μg/d groups, respectively (P ≤ 0.001). Vitamin D3 supplementation had no effect on any of the cardiometabolic risk markers (all P > 0.05), except for lower HDL (-0.12 mmol/L; 95% CI: -0.21, 0.04 mmol/L; P = 0.003) and total cholesterol (-0.21 mmol/L; 95% CI: -0.42, 0.00 mmol/L; P = 0.05) in the 20 μg/d than in the 10 μg/d group, which disappeared in the fully adjusted analysis (P = 0.27 and P = 0.30, respectively).

Conclusions

Supplementation with vitamin D3 at 10 and 20 μg/d, which increased serum 25(OH)D concentrations during the winter-time, had no effect on markers of cardiometabolic risk in healthy 14- to 18-y-old adolescents. This trial was registered at clinicaltrials.gov as NCT02150122.

Vitamin D Deficiency Associated With Markers of Cardiovascular Disease in Children With Obesity

Adult studies have reported associations of low 25-hydroxyvitamin D (25OHD) with dyslipidemia and cardiovascular disease; however, there are scarce pediatric data regarding relationships between vitamin D status and specific lipid markers affecting cardiovascular risk. In this cross-sectional study of children evaluated at university-based pediatric endocrinology clinics, 178 patients meeting criteria for overweight or obesity had 25OHD levels assessed over a 2-year period; 60 of 178 had non-HDL (high-density lipoprotein) cholesterol and fasting lipid parameters performed. Patients with 25OHD <20 ng/mL had significantly higher non-HDL cholesterol (134.76 ± 47.32 vs 108.85 ± 31.14, P < .03), triglyceride (TG)/HDL ratio (3.09 ± 2.26 vs 1.82 ± 1.18, P = .03), total cholesterol (TC)/HDL ratio (4.23 ± 1.23 vs 3.40 ± 1.05, P < .01), TC (184.15 ± 40.19 vs 158.89 ± 30.10, P < .01), and TG (134.76 ± 47.32 vs 78.93 ± 37.46, P < .03) compared with 25OHD ≥20 ng/mL. Vitamin D deficiency was significantly associated with increase in atherogenic lipids and markers of early cardiovascular disease. These findings suggest that vitamin D deficiency may have negative effects on lipid parameters with increase in cardiovascular risk.

Vitamin D Deficiency and Association With Body Mass Index and Lipid Levels in Hispanic American Adolescents

In this retrospective study, vitamin D deficiency was examined with body mass index (BMI) and lipid levels in a sample of Hispanic American adolescents. The prevalence of vitamin D deficiency among 234 subjects aged 13 to 19 years was 27.8%. Vitamin D deficiency was significantly associated with a BMI of 85 kg/m² or higher (odds ratio = 2.02, 95% confidence interval = 1.11-3.69, χ² = 5.37, P = .021), and 55.6% of the sample were overweight or obese (BMI ≥ 85%). In the overweight or obese subjects, vitamin D deficiency was significantly associated with higher mean lipid levels compared with those with adequate vitamin D levels: total cholesterol = 165 ± 28.6 mg/dL versus 145.7 ± 27.5 mg/dL, P = .0003; low-density lipoprotein = 92.7 ± 25.7 mg/dL versus 80.8 ± 21.4 mg/dL, P = .007; and triglycerides = 148.9 ± 97.1 mg/dL versus 90.6 ± 40.7 mg/dL, P = .0000. The mean triglyceride level of 148.9 mg/dL in the overweight or obese subjects was in the dyslipidemic range. In the underweight and healthy weight subjects (BMI ≤ 84), there was no statistically different lipid levels between the vitamin D adequate and vitamin D deficient groups. The effect of vitamin D on lipid levels was confirmed by regression analysis. Elevated lipids and dyslipidemic triglyceride levels, associated with vitamin D deficiency in overweight or obese Hispanic American adolescents, indicates a need for clinical monitoring and appropriate intervention.