Occurrence of vitamin D deficiency in pediatric patients at high risk in West Virginia. South Med J. 2012;105:504-507. [PMID: 23038478 DOI: 10.1097/smj.0b013e3182675e8a]

Vitamin D: Insufficiency, Uncertainty and Achievability

Vitamin D is a prohormone that is essential to good health. As very few foods (fish, egg yolks, milk) are rich in vitamin D, the main source of the vitamin is synthesized in the skin in the presence of ultraviolet B rays from sunlight. However, due to Canada's northern latitude, sufficient amounts of vitamin D cannot be synthesized using sunlight during the fall and winter months and, consequently, there is a concern that many Canadians are not achieving adequate levels of vitamin D. A wide array of inconsistent evidence derived from serum and dietary assessments has been published and the results are inconclusive. This paper serves to outline the issues and challenges regarding nationwide intervention strategies such as fortification to increase vitamin D intake in the Canadian population. Given the potential for excessive intakes and the lack of informed Canadian data, implementing an intervention to increase vitamin D intake in the entire population may be irresponsible; however, further investigation of vitamin D intakes in certain subgroups of the Canadian population is warranted.

The effect of maternal vitamin D deficiency during pregnancy on body fat and adipogenesis in rat offspring

To evaluate the effects of maternal vitamin D deficiency on body fat and adipogenesis in offspring rats, and explore the potential mechanism, we constructed a vitamin D deficient rat model and performed metabolic activity evaluation, body fat monitoring, biochemical analysis, adipogenesis assay, methylation microarray and RNA-seq for their offspring rats. We found the weight of vitamin D deficient (VDD) offspring was gradually higher than that of control (CLT) offspring, and the difference was significant since 10 weeks old. When compared with CTL offspring, the 24 h heat production, peak blood glucose, adipose tissue volume and blood lipid indexes were significantly increased in VDD offspring at 14 weeks old. Moreover, a significant increase in proliferation rate and number of lipid droplets for pre-adipocytes was also observed in VDD offspring group. DNA methylation profiling showed that compared to CTL group, 608 promoters and 204 CpG islands were differentially methylated in the VDD group, involving 305 genes. When combined with the results of RNA-seq, 141 genes of the methylated genes were differentially expressed. In conclusion, vitamin D deficiency during pregnancy may promote the proliferation and differentiation of pre-adipocytes, which may be associated with methylation alterations of genes, ultimately leading to offspring obesity.

Vitamin D Deficiency in Children Undergoing Vertical Expandable Prosthetic Titanium Rib Treatment

BACKGROUND

Vitamin D deficiency is prevalent in the pediatric population and multiple risk factors have been identified. Low vitamin D levels can result in poor bone mineralization and have been associated with a significantly higher risk of forearm fracture in children. Vitamin D deficiency has also been associated with pediatric critical illness. The purpose of this study was to determine whether children undergoing vertical expandable prosthetic titanium rib (VEPTR) treatment have low vitamin D levels.

METHODS

Patients undergoing VEPTR treatment at a single institution were prospectively enrolled (VEPTR). All patients either had a diagnosis of thoracic insufficiency syndrome (TIS), or were at risk of developing TIS secondary to progressive scoliosis or chest wall deformity. Exclusion criteria were patients with rickets and patients receiving vitamin D supplementation at the time of VEPTR insertion. A group of healthy children who presented with fractures during the winter season were used as controls (FX). Vitamin D status and risk factors for vitamin D deficiency were evaluated. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D (25-OH-D) <20 ng/mL and vitamin D insufficiency as serum 25-OH-D between 20 and 29 ng/mL.

RESULTS

Twenty-eight VEPTR and 25 FX patients were compared. The average age was 8.6 years in the VEPTR group and 9.1 years in the FX group. Twenty VEPTR patients (71%) and 19 FX patients (76%) demonstrated low vitamin D levels. The average 25-OH-D level was 27.3 ng/mL in the VEPTR group and 25.4 ng/mL in the FX group. Patient characteristics and vitamin D levels were similar between the groups. No association was found between vitamin D status and sex, race, obesity, or multivitamin use.

CONCLUSIONS

Low vitamin D levels are common in children undergoing VEPTR treatment. In our series, the prevalence of vitamin D deficiency in this patient population was similar to reported rates in the general pediatric population. Vitamin D status should be routinely monitored in children undergoing VEPTR treatment and supplementation should be initiated if necessary.

Vitamin D deficiency is associated with pulmonary exacerbations in children with cystic fibrosis

RATIONALE

Recent literature suggests vitamin D has an effect on lung function and on the lung's ability to fight infection, both important in the cystic fibrosis (CF) population as predictors of morbidity and mortality.

OBJECTIVES

Our study assessed associations between vitamin D and % predicted lung function, pulmonary exacerbations, and first Pseudomonas aeruginosa infection in children with CF. We hypothesized that children with CF who have 25-hydroxy vitamin D (25-OHD) levels less than 30 μg/L would have lower % predicted lung function and more pulmonary exacerbations than those with 25-OHD greater than or equal to 30 μg/L.

METHODS

This retrospective longitudinal study of 130 children aged 6 to 18 years between 2000 and 2012 examined 25-OHD levels classed in three vitamin D groups: sufficient (≥30 μg/L), insufficient (20-29 μg/L), and deficient (<20 μg/L). Longitudinal models followed individuals' changing vitamin D groups over time to compare numbers of pulmonary exacerbations (defined by hospitalization), incidence of first P. aeruginosa infection, and % predicted lung function. Cross-sectional comparisons between vitamin D groups were performed at ages 8, 12, and 16 years.

MEASUREMENTS AND MAIN RESULTS

The prevalence of vitamin D deficiency and insufficiency increased slowly through adolescence. The rate of exacerbations for the deficient vitamin D group, aged 15 to 18 years, was 13.1 per 10 patient-years, significantly higher than 4.3 per 10 patient-years for the insufficient and sufficient vitamin D groups (P < 0.05), which were not significantly different There were no differences between vitamin D groups in pulmonary function or incidence of first P. aeruginosa infection, which was about 2 per 10 patient-years.

CONCLUSIONS

Higher 25-OHD levels in children with CF were associated with lower rates of pulmonary exacerbations and, in adolescents, higher FEV1.

Pathophysiology of cystic fibrosis and drugs used in associated digestive tract diseases

Cystic fibrosis (CF) causes chronic infections in the respiratory tract and alters the digestive tract. This paper reviews the most important aspects of drug treatment and changes in the digestive tract of patients with CF. This is a review of the literature, emphasizing the discoveries made within the last 15 years by analyzing scientific papers published in journals indexed in the Scientific Electronic Library Online, Sciences Information, United States National Library of Medicine and Medical Literature Analysis and Retrieval System Online databases, both in English and Portuguese, using the key words: cystic fibrosis, medication, therapeutic, absorption, digestion. Randomized, observational, experimental, and epidemiological clinical studies were selected, among others, with statistical significance of 5%. This review evaluates the changes found in the digestive tract of CF patients including pancreatic insufficiency, constipation and liver diseases. Changes in nutritional status are also described. Clinical treatment, nutritional supplementation and drug management were classified in this review as essential to the quality of life of CF patients, and became available through public policies for monitoring and treating CF. The information gathered on CF and a multi professional approach to the disease is essential in the treatment of these patients.

The beneficial role of vitamin D in obesity: possible genetic and cell signaling mechanisms

The prevalence rates of overweight and obesity are considered an important public issue in the United States, and both of these conditions are increasing among both children and adults. There is evidence of aberrations in the vitamin D-endocrine system in obese subjects. Vitamin D deficiency is highly prevalent in patients with obesity, and many studies have demonstrated the significant effect of calcitriol on adipocytes. Genetic studies have provided an opportunity to determine which proteins link vitamin D to obesity pathology, including the vitamin D receptor, toll-like receptors, the renin-angiotensin system, apolipoprotein E, vascular endothelial growth factor, and poly (ADP-ribose) polymerase-1. Vitamin D also exerts its effect on obesity through cell-signaling mechanisms, including matrix metalloproteinases, mitogen-activated protein kinase pathways, the reduced form of nicotinamide adenine dinucleotide phosphate, prostaglandins, reactive oxygen species, and nitric oxide synthase.

In conclusion, vitamin D may have a role in obesity. The best form of vitamin D for use in the obese individuals is calcitriol because it is the active form of the vitamin D₃ metabolite, its receptors are present in adipocytes, and modulates inflammatory cytokine expression.