Vitamin D insufficiency in obese children and relation with lipid profile

Left and right ventricular function by echocardiography, tissue doppler imaging, carotid intima media thickness, and asymmetric dimethylarginine levels in female adolescents with vitamin D deficiency

BACKGROUND

The aim of our study was to assess left and right ventricle systolic and diastolic functions in female adolescents with vitamin D deficiency using conventional echocardiography and pulsed-wave tissue Doppler imaging and to investigate carotid intima media thickness and asymmetric dimethylarginine levels.

METHODS

Sixty-six female adolescents were enrolled in this study. The female adolescents were divided into a vitamin D deficiency group (n: 34) and a control group (n: 32). All subjects underwent laboratory blood tests, including asymmetric dimethyl arginine, complete two-dimensional, pulse, and tissue Doppler echocardiography, and measurement of the carotid intima-media thickness.

RESULTS

The vitamin D-deficient female adolescent group had normal left and right ventricle systolic and diastolic functions and normal global systolic and diastolic myocardial performance. In the patients with vitamin D deficiency, the carotid intima-media thickness was higher than that in the controls. In the patients within the vitamin D deficiency group, vitamin D was found to be positively correlated with magnesium and negatively correlated with phosphorus and left atrial dimension.

CONCLUSIONS

The results of this study demonstrate that vitamin D deficiency in female adolescence is associated with normal myocardial geometry and function. Although it has been associated with normal levels of asymmetric dimethyl arginine concentration, high measured carotid intima-media thickness may reflect endothelial dysfunction.

Childhood Obesity: An Updated Review

BACKGROUND

Childhood obesity is an important and serious public health problem worldwide.

OBJECTIVE

This article aims to familiarize physicians with the evaluation, management, and prevention of childhood.

METHODS

A PubMed search was conducted in May, 2021, in Clinical Queries using the key terms "obesity" OR "obese". The search included clinical trials, randomized controlled trials, case-control studies, cohort studies, meta-analyses, observational studies, clinical guidelines, case reports, case series, and reviews. The search was restricted to English literature and children. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Most obese children have exogenous obesity characterized by a growth rate for height above the 50th percentile, normal intelligence, normal genitalia, and lack of historical or physical evidence of an endocrine abnormality or a congenital syndrome. Obese children are at risk for dyslipidemia, hypertension, diabetes mellitus, non-alcoholic fatty liver disease, obstructive sleep apnea, psychosocial disturbances, impaired quality of life, and shorter life expectancy. The multitude of serious comorbidities necessitates effective treatment modalities. Dietary modification, therapeutic exercise, and behavioral modification are the fundamentals of treatment. Pharmacotherapy and/or bariatric surgery should be considered for obese individuals who do not respond to the above measures and suffer from a serious comorbid condition.

CONCLUSION

Childhood obesity, once established, is often refractory to treatment. Most treatment programs lead to a brief period of weight loss, followed by rapid re-accumulation of the lost weight after the termination of therapy. As such, preventive activity is the key to solving the problem of childhood obesity. Childhood obesity can be prevented by promoting a healthy diet, regular physical activity, and lifestyle modification. Parents should be encouraged to get involved in school and community programs that improve their children's nutritional status and physical activity.

Association between serum vitamin D levels and lipid profiles: a cross-sectional analysis

Vitamin D is an essential nutrient that plays a crucial role in calcium homeostasis and bone health. Recent research suggests that vitamin D may also have an impact on lipid metabolism, specifically the level of circulating lipids in the blood. We aim to investigate it role among healthy participate. We conducted a cross-sectional study of 15,600 patients who were referred to the laboratories of university hospitals. We measured the serum levels of Vitamin D as well as triglycerides, total cholesterol, LDL, and HDL using ELISA. We found that the mean serum level of Vitamin D was 40.31 ± 20.79 ng/mL. Of the participants, 16.7% had a serum level of Vitamin D less than 20 ng/mL, 57.7% had a level between 21 and 40 ng/mL, and 13.5% had a level between 41 and 60 ng/mL. Additionally, 12.2% had a level greater than 60 ng/mL. We performed a one-way analysis of variance and found that as the serum level of Vitamin D increased, the mean LDL level decreased significantly. Our study provides evidence of a significant relationship between serum levels of Vitamin D and LDL levels in patients. The findings suggest that vitamin D status may play a role in regulating lipid metabolism and may have implications for the prevention and treatment of cardiovascular disease. Further research is needed to elucidate the underlying mechanisms of this relationship and to determine optimal levels of vitamin D intake for maintaining lipid profiles.

Response to vitamin D replacement therapy in obese children and adolescents with vitamin D deficiency: a randomized controlled trial

OBJECTIVES

Vitamin D deficiency is common in the pediatric group with obesity and is a risk factor for metabolic syndrome. Supplementation of vitamin D may require higher dosing than in normal-weight children. The aim of our study was to investigate the response of supplementation on vitamin D levels and the metabolic profile in youths with obesity.

METHODS

Children and adolescents with obesity (Body mass index >2.3 SDS, age ≤18 years) and hypovitaminosis D (level <20 μg/L) who entered a residential weight-loss program in Belgium, were included during summer. Subjects were randomized: Group 1 received 6,000 IU vitamin D daily for 12 weeks, whereas Group 2 simultaneously participating in the weight-loss program received no supplementation. Differences in vitamin D levels, weight, insulin resistance, lipid patterns, and blood pressure after 12 weeks were assessed.

RESULTS

A total of 42 subjects (12-18 years) with hypovitaminosis D were included, group 1 (n=22) received supplementation after randomization. After 12 weeks, a median increase in vitamin D levels of 28.2 (24.1-33.0) and 6.7 (4.1-8.4) µg/L was observed in group 1 and group 2, respectively (p-value<0.001), resulting in vitamin D sufficiency in 100 and 60% of subjects. No significant differences in weight loss (p-value 0.695), insulin resistance (p-value 0.078), lipid patterns (p-value 0.438), or blood pressure (p-value 0.511) were observed between both groups after 12 weeks of treatment.

CONCLUSIONS

Supplementation with 6,000 IU vitamin D daily during 12 weeks in children and adolescents with obesity and hypovitaminosis D is safe and sufficient to reach vitamin D sufficiency. However, no positive effects on weight loss, insulin resistance, lipid patterns, or blood pressure were observed.

Differences in Cardiometabolic Biomarkers between Elementary School-Age Latinx Children with Obesity versus Healthy Weight

OBJECTIVES

Low-income Latinx youth are disproportionately affected by obesity, which results in an increased risk of cardiometabolic abnormalities. Biomarker tracking may be useful for the early identification of obesity comorbidities in young Latinx children. Hence, we aimed to compare cardiometabolic biomarkers between age- and sex-matched pairs of elementary school-aged Latinx children with obesity versus healthy weight.

METHODS

This case-control study compared cardiometabolic biomarkers between 13 pairs of age- and sex-matched elementary school-age (median 6.5 years) Latinx children with obesity (body mass index for age ≥ 95th percentile) as compared with their healthy weight (between the 5th and 85th percentiles) counterparts. Anthropometric measures and a fasted venous blood sample were taken for the analysis of lipids, glycemic, inflammatory, endocrine, and hepatic markers. Group differences were tested by the Mann-Whitney U or χ² test.

RESULTS

Cases had higher insulin (P = 0.003), hemoglobin A1c (P = 0.002), triglycerides (P = 0.023), and C-reactive protein (P < 0.001) and lower high-density lipoprotein (P = 0.002). Hepatic markers were similar, with alanine aminotransferase elevated among both groups.

CONCLUSIONS

The aforementioned biomarkers may be more sensitive to higher adiposity risk in this young Latinx population; however, elevated hepatic markers may indicate an ethnic/genetic predisposition to abnormal liver function. Research should be replicated in a larger group to confirm these findings.

The link between vitamin D, chemerin and metabolic profile in overweight and obese children - preliminary results

Background

Vitamin D affects adipogenesis, oxidative stress, inflammation, secretion of adipocytokines, lipid metabolism and thermogenesis. Some researchers postulate that those effects could be exerted by the influence of vitamin D on chemerin levels.

Aim of the study

We aimed to investigate if there is a link between serum 25-hydroksyvitamin D [25(OH)D], chemerin and metabolic profile in overweight and obese children before and after vitamin D supplementation.

Material and methods

The prospective study included 65 overweight and obese children aged 9.08-17.5 years and 26 peers as a control. None of the patients in the study group had received vitamin D within the last twelve months before the study.

Results

The study group had lower baseline 25(OH)D (p<0.001) and higher chemerin (p<0.001), triglycerides (TG, p<0.001), triglycerides/high density lipoprotein cholesterol (TG/HDL-C, p<0.001), C-reactive protein (CRP, p<0.05), fasting insulin (p<0.001), Homeostasis Model Assessment - Insulin Resistance (HOMA-IR, p<0.001), alanine aminotransferase (ALT, p<0.001) and uric acid (p<0.001) compared to the control group. Baseline vitamin D was related to fasting insulin (R=-0.29, p=0.021), HOMA-IR (R=-0.30, p=0.016), HDL-C (R=0.29, p=0.020) and uric acid (R=-0.28, p=0.037) in the study group. Baseline chemerin was related to insulin at 30' (R=0.27, p=0.030), 60' (R=0.27, p=0.033), 90' (R=0.26, p=0.037) and 120' (R=0.26, p=0.040) during the oral glucose tolerance test (OGTT) and ALT (R=0.25, p=0.041) in the study group. Correlation between vitamin D and chemerin (R=-0.39, p=0.046) was found only in the control group. After six months of vitamin D supplementation a decrease in CRP (p<0.01), total cholesterol (p<0.05), ALT (p<0.01), glucose at 150' OGTT (p<0.05) was observed. Moreover, we noticed a tendency for negative association between 25(OH)D and chemerin levels (p=0.085). Multivariable backward linear regression models were build using baseline vitamin D, baseline chemerin and six months chemerin as the dependent variables.

Conclusions

Our study confirmed that vitamin D has positive effect on metabolic profile in overweight and obese children. The relationship between vitamin D and chemerin is not clear, nevertheless we have observed a tendency to decrease chemerin concentrations after improving vitamin D status, even without a significant reduction in body fat mass.

Vitamin D and Healthcare Service Utilization in Children: Insights from a Machine Learning Approach

Vitamin D deficiency and insufficiency is a global health issue: an association has been demonstrated between vitamin D deficiency and a myriad of acute and chronic illnesses. Data regarding vitamin D status among children hospitalized with non-critical illnesses are scanty. We aimed to: (1) identify profiles of children hospitalized due to non-critical illnesses, using vitamin D levels as the driving outcome; (2) assess the association between patient profiles and length of stay. The study included 854 patients (1−17 years old) who underwent blood tests for detecting vitamin D levels. A regression tree was used to stratify patients. The relationship between vitamin D levels and length of stay was explored using Poisson regression. The regression tree identified three subgroups. Group A (16%): African, North African, Hispanic, and Indian patients. Group B (62%): Caucasian and Asian patients hospitalized for respiratory, metabolic, ill-defined, infective, and genitourinary diseases. Group C (22%): Caucasian and Asian patients hospitalized for digestive, nervous, and musculoskeletal diseases, blood and skin diseases, and injuries. Mean serum vitamin D level (ng/mL) was 13.7 (SD = 9.4) in Group A, 20.5 (10.0) in Group B, and 26.2 (12.6) in Group C. Group B was associated with the highest BMI z-score (p < 0.001) and the highest frequency of preterm births (p = 0.041). Mean length of stay was longer in Group A than in the other groups (p < 0.001) and decreased significantly by 9.8% (p = 0.024) in Group A and by 5% (p = 0.029) in Group B per 10 ng/mL increase in vitamin D level. We identified three subgroups of hospitalized children, defined according to ethnicity and discharge diagnosis, and characterized by increasing vitamin D levels. Vitamin D levels were associated with length of hospitalization.

Vitamin D status is favorably associated with the cardiovascular risk factors in adults with obesity

BACKGROUND & AIMS

Previous investigations have been indicated that vitamin D deficiency is an amendable risk for cardiovascular disease (CVD) in the general populations. Limited data is available concerning the relationship of vitamin D status and risk factors of CVD in the individuals with obesity and the existing data are highly controversial. We investigated whether serum vitamin D situation is related to multiple traditional CVD risk factors in Iranian obese subjects.

METHODS

A cross-sectional study was done among 214 Iranian adults with obesity (94 males and 120 females) aged 20-60 years, who attended the specialized outpatient clinics in Zabol city. Participants were categorized as vitamin D sufficient, insufficient, and deficient according to their serum 25(OH)D concentrations. Afterward, the presence of hypercholesterolemia, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), high low-density lipoprotein cholesterol (LDL-C) as well as diabetes, hypertension, and high serum concentrations of high-sensitivity C-reactive protein (hs-CRP) as CVD risk factors were evaluated in the participants.

RESULTS

There was a noticeable regular trend regarding hypercholesterolemia (p = 0.008), high LDL-C (p = 0.024), hypertension (p = 0.021), and high hs-CRP (p < 0.0001) across various categories of vitamin D status. In adjusted model, vitamin D-deficient subjects were at higher risk for having hypercholesterolemia (OR: 3.22, p = 0.031), high LDL-C (OR: 2.37, p = 0.047), hypertension (OR: 2.32, p = 0.042), and high hs-CRP (OR: 5.49, p = 0.001) than ones with sufficient vitamin D status.

CONCLUSIONS

Vitamin D deficiency in obese subjects was found to be strongly related to higher risk of unfavorable lipid profile, hypertension, and high hs-CRP.

Vitamin D is not associated with body composition and metabolic profile among Brazilian children with 25-hydroxyvitamin D ≥ 75 nmol/L: A cross-sectional study

BACKGROUND AND AIMS

The association of vitamin D with cardiovascular disease risk factors among children remains inconclusive, and there is a lack of studies that evaluate children with optimal serum 25-hydroxyvitamin D [25(OH)D]. Thus, this study aimed to analyze the relationship between serum 25(OH)D and body composition and metabolic profile among Brazilian children with sufficient serum 25(OH)D.

METHODS AND RESULTS

A cross-sectional study was conducted with 88 Brazilian children aged 4-11 years. Self-reported race, physical activity, anthropometry (body mass and height), body composition (waist circumference, body fat percentage, fat free mass, triceps and subscapular skinfolds), biochemical profile [lipid fractions, fasting glucose and 25(OH)D] and blood pressure data were collected. No difference was found in sex, self-reported race, physical activity, age, anthropometry, body composition, biochemical parameters and blood pressure between children with 25(OH)D 75-99 and ≥ 100 nmol/L. In addition, there was no association between serum vitamin D and body composition and metabolic profile.

CONCLUSIONS

Serum 25(OH)D was not associated with body composition and metabolic profile among Brazilian children with sufficient serum 25(OH)D. Further studies among children with serum levels ≥ 75 nmol/L are needed to confirm this finding.

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.

Association of Vitamin D Status and Physical Activity with Lipid Profile in Korean Children and Adolescents: A Population-Based Study

Dyslipidemia is one of the important influencing factors of cardiovascular health in the youth, and thus, assessment of its etiology is important. We aimed to investigate the association of dyslipidemia with vitamin D and physical activity in Korean children and adolescents. Data of 3183 subjects aged 12–18 years in the Korea National Health and Nutrition Examination Survey were analyzed. Participants were divided into subgroups according to sex, body mass index, 25-hydroxyvitamin D levels, and lipid profile. The mean 25-hydroxyvitamin D level was 16.15 ng/mL, which was below normal. In total, 79.3% of the subjects had vitamin D deficiency. Females had lower vitamin D levels and a higher incidence of dyslipidemia compared to males. Vitamin D deficiency was significantly associated with high density lipoprotein cholesterol (HDL-C) levels. The low HDL-C group consisted of a higher proportion of subjects with vitamin D deficiency and low physical activity. This study suggests that vitamin D deficiency is prevalent in Korean children and adolescents. Vitamin D deficiency and low physical activity are related with low HDL-C levels. Maintaining sufficient vitamin D levels and physical activity may help prevent dyslipidemia.

Adaptive Neuro-Fuzzy Inference System-Based Exploration of the Interrelationships of 25-Hydroxyvitamin D, Calcium, Phosphorus with Parathyroid Hormone Production

The rationale of the current study was to assess the prevalence of 25-hydroxyvitamin D (25-OHD) deficiency and hyperparathyroidism in South Indian population and to explore interrelationships of 25-OHD, Ca, P towards parathyroid hormone (PTH) production using adaptive neuro-fuzzy inference system (ANFIS). A total of 407 subjects (228 men 179 women) with the mean age 56.8 ± 14.1 were tested for these parameters. In view of the skewed distribution of biochemical variables, data segregation was performed in tertiles and this data was trained to generate fuzzy interference system based on subclusters. The optimized model had 358 nodes and followed 44 fuzzy rules for prediction. This ANFIS model demonstrates that the deficiency of 25-OHD and Calcium triggers PTH production. PTH elevation is significant when Phosphorus is in the highest tertile. The associations observed by this model were consistent with the Kendall-Tau correlation matrix, which revealed inverse associations of Ca with P; and Ca with PTH and positive associations of P with PTH, and Ca with 25-OHD. Furthermore, the association statistics of the machine learning algorithm were also consistent, which suggested that depletion of Ca below 8.245 mg/dl was shown to elevate PTH levels greater than 167 pg/ml when P > 4.66. Subnormal depletion in 25-OHD (9.3-16.2 ng/ml) is associated with subnormal elevation in PTH (47-73.6 pg/ml). To conclude, ANFIS and machine learning algorithm are in agreement with each other in stating that 25-OHD deficiency triggers lower calcium levels, lower calcium and higher phosphorus trigger PTH production.

Relationship between Vitamin D Level and Lipid Profile in Non-Obese Children

Vitamin D deficiency is associated with not only cardiovascular disease itself but also cardiovascular risk factors, including obesity, hypertension, diabetes, hyperglycemia, and dyslipidemia. This study aimed to investigate the relationship between vitamin D level and lipid profile in non-obese children. A total of 243 non-obese healthy volunteers, aged 9-18 years, were enrolled from March to May 2017. Their height and weight were measured, and body mass index was calculated. Subjects underwent blood tests, including measurements of vitamin D (25(OH)D) level and lipid panels, and were divided into either the vitamin D-deficient group (<20 ng/mL) or normal group. The student's t-test and a simple linear regression analysis were used to estimate the association between vitamin D level and lipid profile. Overall, 69.5% of non-obese children (n = 169) had a 25(OH)D level of less than 20 ng/mL. The vitamin D-deficient group showed higher triglyceride (TG) level and TG/high-density lipoprotein cholesterol (HDL-C) ratio than the normal group (TG level: 90.27 vs. 74.74 mmol/L, p = 0.003; TG/HDL-C ratio: 1.753 vs. 1.358, p = 0.003). Vitamin D level seems to affect the lipid profile, even in non-obese children, and a low vitamin D level may progress to dyslipidemia or obesity in non-obese children.

Obesity and hypovitaminosis D: causality or casualty?

Epidemiological studies reported that vitamin D deficiency represents an increasingly widespread phenomenon in various populations. Vitamin D deficiency is considered a clinical syndrome determined by low circulating levels of 25-hydroxyvitamin D (25(OH)D), which is the biologically-inactive intermediate and represents the predominant circulating form. Different mechanisms have been hypothesized to explain the association between hypovitaminosis D and obesity, including lower dietary intake of vitamin D, lesser skin exposure to sunlight, due to less outdoor physical activity, decreased intestinal absorption, impaired hydroxylation in adipose tissue and 25(OH)D accumulation in fat. However, several studies speculated that vitamin D deficiency itself could cause obesity or prevent weight loss. The fat-solubility of vitamin D leads to the hypothesis that a sequestration process occurs in body fat depots, resulting in a lower bioavailability in the obese state. After investigating the clinical aspects of vitamin D deficiency and the proposed mechanisms for low 25(OH)D in obesity, in this manuscript we discuss the possible role of vitamin D replacement treatment, with different formulations, to restore normal levels in individuals affected by obesity, and evaluate potential positive effects on obesity itself and its metabolic consequences. Food-based prevention strategies for enhancement of vitamin D status and, therefore, lowering skeletal and extra-skeletal diseases risk have been widely proposed in the past decades; however pharmacological supplementation, namely cholecalciferol and calcifediol, is required in the treatment of vitamin D insufficiency and its comorbidities. In individuals affected by obesity, high doses of vitamin D are required to normalize serum vitamin D levels, but the different liposolubility of different supplements should be taken into account. Although the results are inconsistent, some studies reported that vitamin D supplementation may have some beneficial effects in people with obesity.

An exploratory analysis of associations of diet, sun exposure, and body composition with 25OHD at five years of age: Findings from the ROLO Kids Study

Serum 25-hydroxyvitamin D (25OHD) is the main circulating form of vitamin D in the blood. Vitamin D status in adults is determined by numerous factors such as oral intake, skin generation, and body composition. However, there is limited understanding regarding determinants of 25OHD in young children. The aim of this study was to identify modifiable factors that may act as determinants of 25OHD at five years of age. Analysis conducted on 79 children from the ROLO Kids study. Dietary intakes and dietary habits were measured using a food frequency questionnaire and levels of sun exposure were assessed using a lifestyle questionnaire, both completed by the mother. Child weight, height, and skinfolds were measured. Vitamin D status was sufficient (25OHD > 50 nmol/L) in 61% of the participants. Neither reported dietary vitamin D nor calcium intake was significantly associated with 25OHD. Intakes of standard milk, eggs, and oily fish were not associated with 25OHD. However, reported consumption of fortified milk, and more than 7 bowls of cereal a week were independently associated with higher 25OHD (p < 0.001 and p = 0.049, respectively). Sun exposure (measured as obtaining at least half an hour of sun per day) was not significantly associated with 25OHD, but reported use of sunscreen was associated with higher 25OHD (p = 0.016). There was no association of body composition with 25OHD. These findings suggest the primacy of dietary and lifestyle habits as indicators of 25OHD in early childhood. This may have utility in identifying at-risk individuals for public health campaigns about education surrounding dietary habits, which may be useful to ensure sufficient vitamin D status within this age group.

Vitamin D improves vascular function and decreases monoamine oxidase A expression in experimental diabetes

The active form of vitamin D, 1,25-dihydroxycholecalciferol (1,25(OH)₂D₃), was reported to improve vascular function in patients with diabetes, yet the underlying mechanisms remain to be fully elucidated. Monoamine oxidase (MAO), a mitochondrial enzyme, with two isoforms (A and B) that generates hydrogen peroxide (H₂O₂) as by-product, has been recently reported to contribute to the pathogenesis of endothelial dysfunction in diabetes. The present study assessed the interaction between vitamin D and MAO in the vascular wall in the setting of type 1 experimental diabetes. To this aim, diabetes was induced in male Wistar rats via a single injection of streptozotocin (STZ, 50 mg/kg, IP) and 1 month later thoracic aortas were harvested and used for organ bath studies and H₂O₂ measurements. MAO expression was assessed by immunohistochemistry and RT-PCR. Endothelial function was evaluated in isolated aortic rings in the absence vs. presence of 1,25(OH)₂D₃ (100 nM, 24 h incubation). In diabetic animals, we found a significant reduction in the endothelial-dependent relaxation to acetylcholine and an increased expression of the MAO-A isoform, respectively. Vitamin D significantly improved vascular function, mitigated oxidative stress and decreased MAO-A expression in diabetic vascular preparations. In conclusion, MAO-A is induced in diabetic aortas and vitamin D can improve diabetes-induced endothelial dysfunction by modulating the MAO-A expression.

Vitamin D in pediatric age: consensus of the Italian Pediatric Society and the Italian Society of Preventive and Social Pediatrics, jointly with the Italian Federation of Pediatricians

Vitamin D plays a pivotal role in the regulation of calcium-phosphorus metabolism, particularly during pediatric age when nutritional rickets and impaired bone mass acquisition may occur.Besides its historical skeletal functions, in the last years it has been demonstrated that vitamin D directly or indirectly regulates up to 1250 genes, playing so-called extraskeletal actions. Indeed, recent data suggest a possible role of vitamin D in the pathogenesis of several pathological conditions, including infectious, allergic and autoimmune diseases. Thus, vitamin D deficiency may affect not only musculoskeletal health but also a potentially wide range of acute and chronic conditions. At present, the prevalence of vitamin D deficiency is high in Italian children and adolescents, and national recommendations on vitamin D supplementation during pediatric age are lacking. An expert panel of the Italian Society of Preventive and Social Pediatrics reviewed available literature focusing on randomized controlled trials of vitamin D supplementation to provide a practical approach to vitamin D supplementation for infants, children and adolescents.

Vitamin D levels in childhood and adolescence and cardiovascular risk factors in a cohort of healthy Australian children

As the prevalence of obesity appears to be increasing in Australia's youth the overall objective of this study was to examine serum 25-hydroxyvitamin D (25OHD) concentrations in a cohort of 8-year-olds (n=249) followed up at age 15 (n=162) and explore associations between 25OHD with cardiovascular disease (CVD) risk factors in these populations. This was done in two stages: the first, two cross-sectional analyses (at ages 8 and 15); and the second, a prospective analysis from age 8 to 15. At both ages data on 25OHD, blood lipids, and anthropometry were measured. Date of blood draw was used as a surrogate of sunlight exposure. Results were then analysed by multivariate linear analyses taking into account interaction and confounding. Mean 25OHD concentrations decreased from 94±25nmol/L to 63±16nmol/L between age 8 and 15 years (p<0.001). On cross-sectional analysis of 8year olds, no CVD risk factor was found to be significantly associated with 25OHD concentrations. On cross-sectional analysis of 15year olds lower 25OHD levels were significantly associated with higher body fat (adjusted β=-0.24, p=0.003). Prospectively, lower 25OHD levels in 8-year-old boys, but not girls, were significantly associated with higher blood total cholesterol (adjusted β=-0.28, p=0.040) and triglyceride levels (adjusted β=-0.33, p=0.030) at age 15. The limitation of these data is the relatively small sample sizes, however these results suggest that low 25OHD in childhood needs to be further investigated in larger cohort studies as there may be later cardiovascular consequences in adolescence.

Lower vitamin D intake is associated with low HDL cholesterol and vitamin D insufficiency/deficiency in Brazilian children

OBJECTIVE

To evaluate the association of vitamin D intake with dyslipidaemia and vitamin D insufficiency/deficiency in Brazilian children and identify the main food group sources of this nutrient in the sample.

DESIGN

A cross-sectional study carried out with a representative sample. Blood was collected after 12 h of fasting. Laboratory tests were performed to determine total cholesterol, HDL cholesterol (HDL-C), LDL cholesterol, TAG, apoB, apoA1, 25-hydroxyvitamin D and parathyroid hormone. Dietary intake was evaluated by a 24 h recall.

SETTING

Viçosa, Minas Gerais, Brazil.

SUBJECTS

Children between 8 and 9 years old enrolled in urban schools (n 378).

RESULTS

We found an elevated prevalence of inadequate vitamin D intake (91·3 %), dyslipidaemia (72·8 %) and vitamin D insufficiency/deficiency (56·2 %). The food groups that contributed the most to vitamin D intake were dairy products and fish. Lower vitamin D intake was associated with increased prevalence of both low HDL-C (prevalence ratio=2·51; 95 % CI 1·02, 6·18; P<0·05) and vitamin D insufficiency/deficiency (prevalence ratio=1·61; 95 % CI 1·01, 2·58; P<0·05).

CONCLUSIONS

Given the elevated prevalence of inadequate vitamin D intake and its association with low HDL-C and vitamin D insufficiency/deficiency, it is important to develop specific actions in food and nutritional education as well as programmes that stimulate and facilitate access to vitamin D food sources, such as dairy products and fish.

Spotlight on vitamin D receptor, lipid metabolism and mitochondria: Some preliminary emerging issues

Transcriptional control and modulation of calcium fluxes underpin the differentiating properties of vitamin D (1,25(OH)₂D₃). In the latest years however few studies have pointed out the relevance of the mitochondrial effects of the hormone. It is now time to focus on the metabolic results of vitamin D receptor (VDR) action in mitochondria, which can explain the pleiotropic effects of 1,25(OH)₂D₃ and may elucidate few contrasting aspects of its activity. The perturbation of lipid metabolism described in VDR knockout mice and vitamin D deficient animals can be revisited based on the newly identified mechanism of action of 1,25(OH)₂D₃ in mitochondria. From the same point of view, the controversial role of 1,25(OH)₂D₃ in adipogenesis can be better interpreted.

Seasonal variations of vitamin D and its relation to lipid profile in Iranian children and adults

BACKGROUND

Vitamin D has a multitude of functional properties and acts like a hormone in the body. Its effect on the lipid profile is one of the proposed mechanisms for its relationship with many disorders during its deficiency. But, this relationship is still conflicting and debatable, so this study was conducted to determine the association between serum level of vitamin D and lipid profiles, including serum concentrations of cholesterol, triglyceride (TG), HDL, and LDL in healthy subjects.

METHODS

In this cross-sectional study, 541 volunteers with age of 5-60 years from normal and healthy subjects were selected via random sampling. Demographics and history of daily or weekly sunlight exposures were recorded. Measuring vitamin D was done in two consecutive seasons: winter and summer. Ten milliliters of peripheral venous blood sample was withdrawn after an overnight fasting. Serum levels of 25(OH) D (25, hydroxy vitamin D3) were measured using the enzyme-linked immunosorbent assay (ELISA), and the Confirmatory test was done by high-performance liquid chromatography (HPLC).

RESULTS

Mean age in the total mixed population was 30.83 ± 14.02 years. Subjects were 50.5% male and 49.5% female. Mean 25(OH) D in the total population for winter and summer were 45.8 ± 24.26 ng/ml and 55.24 ± 37.47 ng/ml respectively. In the total population, 38.08% were vitamin D deficient. Comparing serum lipid levels in the summer and winter showed a significant difference for cholesterol, LDL, and HDL, but no significant effect was found for TG. Analysis for the comparison of lipid profiles between the two genders in winter showed that there were significant differences in all lipid profiles except for LDL, while such analysis for summer revealed significant difference just for TG. In multivariate analysis, there was a significant mean difference only for LDL in subgroups with vitamin D insufficiency and deficiency. There was no correlation between Vitamin D and lipid profiles.

CONCLUSIONS

Vitamin D is different between the two seasons regardless of gender variations. Its status showed some significant relationship with some lipid profiles (cholesterol, LDL, and HDL) during the two seasons. There were different results among winter and summer based on the gender.

Interrelationship between serum 25-hydroxyvitamin D3 concentration and lipid profiles in premenopausal Indian women

CONTEXT

Vitamin D deficiency is prevalent worldwide, and observational studies have associated it with an atherogenic lipid profile.

AIM

To determine the interrelationship between Vitamin D and lipid profile in apparently healthy premenopausal Indian women, considering confounding factors such as lifestyle that independently influence lipids.

SETTING AND DESIGN

Cross-sectional study.

SUBJECTS AND METHODS

One hundred and twenty healthy premenopausal women (20-45 year) were recruited from Gujarat, India. Data were collected on anthropometry, physical activity, sunlight exposure, and diet. Fasting blood samples were collected for the measurement of serum 25-hydroxyvitamin D₃ (25[OH]D), parathyroid hormone, and lipid profile.

STATISTICAL ANALYSIS

Pearson's correlation coefficient was used to derive correlation between serum 25[OH]D concentrations and serum lipids.

RESULTS

Ninety-three percent women showed Vitamin D deficiency (serum 25[OH]D < 20 ng/ml). Serum 25(OH)D concentrations showed significant inverse correlation with total cholesterol (TC) (r = -0.202, P = 0.027), triglycerides (TG) (r = -0.284, P = 0.002), and low-density lipoprotein-cholesterol (LDL-C) (r = -0.184, P = 0.044) and positive correlation with high-density lipoprotein-cholesterol (HDL-C) (r = 0.250, P = 0.006). On dichotomizing the population according to median 25(OH)D concentration (11.1 ng/dl), no significant differences were observed between the groups for anthropometry, sunlight exposure, and lifestyle. Serum lipid profiles were significantly different, above median serum 25(OH)D concentration group showed favorable serum lipids (TC: 179.3 ± 30 vs. 191.8 ± 31.7 mg/dl; TG: 140 ± 39.1 vs. 165.5 ± 53.4 mg/dl; LDL-C: 100 ± 30.2 vs. 112 ± 32 mg/dl; HDL-C: 53 ± 14 vs. 47.6 ± 9.3 mg/dl)(P < 0.05).

CONCLUSIONS

This study demonstrates that association of 25(OH)D concentrations with lipid profile even after considering lifestyle factors which independently influence lipids. Intervention trials would be required to prove this association to be causation.

An Updated Mini Review of Vitamin D and Obesity: Adipogenesis and Inflammation State

Vitamin D related research continues to expand and theorise regarding its involvement in obesity, as both hypovitaminosis D and obesity strike in pandemic proportions. Vitamin D plays an important role in immune system through Vitamin D Receptors (VDR), which are transcription factors located abundantly in the body. Due to this characteristic, it is potentially linked to obesity, which is a state of inflammation involving the release of cytokines from adipose tissue, and exerting stress on other organs in a state of positive energy balance. Research trials in the past couple of years and systematic reviews from SCOPUS and MEDLINE will be discussed. The role of Vitamin D throughout the lifespan (from fetal imprinting until older age), and in various other obesity mediated chronic conditions shall be highlighted. Various mechanisms attributed to the inverse relationship of Vitamin D and obesity are discussed with research gaps identified, particularly the role of adipokines, epigenetics, calcium and type of adipose tissue.

Lipid changes and their relationship with vitamin D levels in children under 18 years with type 1 diabetes

OBJECTIVE

To analyze lipid changes and their relationship with 25-hydroxy vitamin D3 (25-OH-D) levels in patients under 18 years old with type 1 diabetes mellitus (T1DM).

MATERIAL AND METHODS

A cross-sectional, descriptive study. Patients under 18 years with T1DM were enrolled by consecutive, nonrandomized sampling. Data collected included sex, age, pubertal stage, time since T1DM onset, weight, height, body mass index (BMI), waist circumference, glycosylated hemoglobin (HbA1c), 25-OH-D, total cholesterol (TC), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C), and triglycerides (TG). Results were stratified by sex, age, and pubertal stage. Data were analyzed using SPSS(®).

RESULTS

Ninety patients with a mean age of 11.7 ± 3.6 years (51.1% males) and mean HbA1c levels of 7.5 ± 1.3% were enrolled. Of these, 26.6% had 25-OH-D levels<20 ng/mL and 13.3% 25-OH-D levels ≤ 15 ng/mL. No differences were found in 25-OH-D between patients with overweight or obesity and the rest. HDL-C levels<40 ng/mL were found in 1.1%, 34.4% had LDL-C levels ≥ 100 mg/dL, and 2.2% had TG levels ≥ 150 mg/dL. Patients with 25-OH-D<20 ng/mL had higher TG levels than the rest (76.80 ± 45.62 vs 57.55 ± 26.08; P=.04) in the multivariate analysis controlled for BMI, waist circumference, and HbA1c. A correlation was found between 25-OH-D and TG levels (-0.230; P=.029).

CONCLUSIONS

Patients in our population with vitamin D deficiency had higher TG levels. Long-term follow-up should be performed to understand the potential impact of such levels on diabetes-related complications.

Functional foods as potential therapeutic options for metabolic syndrome

Obesity as part of metabolic syndrome is a major lifestyle disorder throughout the world. Current drug treatments for obesity produce small and usually unsustainable decreases in body weight with the risk of major adverse effects. Surgery has been the only treatment producing successful long-term weight loss. As a different but complementary approach, lifestyle modification including the use of functional foods could produce a reliable decrease in obesity with decreased comorbidities. Functional foods may include fruits such as berries, vegetables, fibre-enriched grains and beverages such as tea and coffee. Although health improvements continue to be reported for these functional foods in rodent studies, further evidence showing the translation of these results into humans is required. Thus, the concept that these fruits and vegetables will act as functional foods in humans to reduce obesity and thereby improve health remains intuitive and possible rather than proven.