Adolescent Girls in Maine Are at Risk for Vitamin D Insufficiency

Mediated relationship between Vitamin D deficiency and reduced pulmonary function by copper in Taiwanese young adults

BACKGROUND

Vitamin D deficiency is prevalent worldwide and associated with worse outcomes in various lung diseases. This study examines the association between vitamin D deficiency and pulmonary function in healthy young adults.

METHODS

This prospective cohort study (2017-2019) explored the impact of vitamin D deficiency on pulmonary function in a community-based young adult population. Pulmonary function was assessed via spirometry, with serum 25-hydroxyvitamin D [25(OH)D] and urinary copper levels quantified. Multivariate regression was used to estimate the relationship between vitamin D levels and lung function, with mediation analysis evaluating copper's role.

RESULTS

The study included 1034 participants, average age 33.45 years, 41.93 % male. The median 25(OH)D level was 19.20 ng/mL (Interquartile Range: 13.48-24.90 ng/mL). Over half (54.74 %) had 25(OH)D levels below 20 ng/mL. Higher 25(OH)D levels were associated with better forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁). Trends suggested subgroup differences, but these were not statistically significant, indicating a consistent effect of 25(OH)D on pulmonary function across groups. SEM analysis suggested urinary copper as a mediator between 25(OH)D levels and FVC.

CONCLUSION

Vitamin D deficiency is significantly associated with reduced pulmonary function in young adults in Taiwan.

Association Between Adequate Serum 25(OH)D Levels and Atherogenic Dyslipidemia in Young Adults

AIM

This study aimed to investigate the association between vitamin D deficiency and novel biomarkers of atherogenic dyslipidemia among young adults.

METHOD

A total of 976 young adults were recruited between 2011 and 2019. Their serum 25(OH)D levels were measured, and lipid profile markers, including low-density lipoprotein cholesterol (LDL-C), low-density lipoprotein triglyceride (LDL-TG), and small-dense low-density lipoprotein cholesterol (sdLDL-C), were assessed as novel biomarkers of atherogenic dyslipidemia. Multivariable linear regression was used to analyze the association between vitamin D levels and lipid profile markers. Odds ratios were calculated to assess the risk of atherogenic dyslipidemia in individuals with serum 25(OH)D levels below 30 ng/mL compared to those with levels above 30 ng/mL. Structural equation modeling (SEM) was employed to explore potential mediation pathways.

RESULTS

The study found a significant association between vitamin D levels and lower levels of LDL-C, LDL-TG, sdLDL-C, non-high-density lipoprotein cholesterol (non-HDL-C), triglycerides, and total cholesterol. Individuals with serum 25(OH)D levels below 30 ng/mL exhibited significantly higher odds ratios for developing atherogenic dyslipidemia in a dose-response pattern compared to those with vitamin D levels above 30 ng/mL. Notably, structural equation modeling (SEM) analysis revealed that vitamin D did not affect atherogenic lipid markers through the mediation of insulin resistance markers or high-sensitivity C-reactive protein.

CONCLUSION

This study provides evidence of an association between vitamin D deficiency and atherogenic dyslipidemia in young adults. It further highlights that individuals with serum 25(OH)D levels below 30 ng/mL are at a significantly higher risk of developing atherogenic dyslipidemia in a dose-response manner compared to those with higher vitamin D levels. These findings underscore the potential role of vitamin D in dyslipidemia management and emphasize the importance of maintaining sufficient vitamin D levels for cardiovascular health in young adults.

Pediatric Fractures: Does Vitamin D Play a Role?

BACKGROUND

Vitamin D (25-OHD) deficiency and insufficiency are reported in about half of all children. The literature on low 25-OHD and pediatric fracture risk presents inconsistent results. This study evaluates the association between pediatric fractures and 25-OHD, parathyroid hormone (PTH), and calcium.

METHODS

This is a prospective case-control study in 2 urban pediatric emergency departments (2014-2017). Patients aged 1 to 17 requiring intravenous access were enrolled. Demographics, nutrition, and activity information were recorded and levels of 25-OHD, calcium, and PTH were measured.

RESULTS

Two hundred forty-five subjects were enrolled: 123 fractures and 122 controls. Overall, the mean 25-OHD level was 23 ng/mL±8.5: 52 (21%) of patients were 25-OHD sufficient; 193 (79%) were not. Ninety-six percent of patients with lower extremity fractures had low 25-OHD versus 77% of patients with upper extremity fractures (P=0.024). The fracture cohort was younger (P=0.002), included more males (P=0.020), and spent more time playing outdoor sports (P=0.011) than the control cohort. The 25-OHD level (fracture 22.8 ng/mL±7.6 vs. nonfracture 23.5 ng/mL±9.3, P=0.494) and median calcium level (fracture 9.8 mg/dL vs. nonfracture 10.0 mg/dL, P=0.054) were similar between cohorts. The median PTH level was higher in the fracture than the control cohort (33 vs. 24.5 pg/mL; P<0.0005); PTH was elevated to hyperparathyroidism (>65 pg/mL) in 13% of fractures and 2% of controls (P=0.006). Matched subgroup analysis of 81 fracture patients and 81 controls by age, gender, and race showed that PTH was the only variable independently associated with increased odds of fracture (odds ratio=1.10, 95% CI, 1.01-1.19, P=0.021) in a model adjusted for vitamin D sufficiency and time spent playing outdoor sports.

CONCLUSIONS

Low 25-OHD is common in children with fractures but we found no difference in 25-OHD levels between fracture and nonfracture cohorts. This research can impact evidence-based guidelines on vitamin D level screening and/or supplementation after fracture.

LEVEL OF EVIDENCE

Diagnostic level IV-case-control study.

Vitamin D deficiency in early life regulates gut microbiome composition and leads to impaired glucose tolerance in adult and offspring rats

Vitamin D has been found to be involved in glucose metabolism in recent years. Its deficiency is very common, especially in children. Whether vitamin D deficiency in early life affects adult diabetes risk is unknown. In this study, a rat model of early life vitamin D deficiency (F1 Early-VDD) was established by depriving it of vitamin D from the 0 to the 8th week. Further, some rats were switched to normal feeding conditions and sacrificed at the 18th week. Other rats were mated randomly to generate offspring rats (F2 Early-VDD), and F2 rats were fed under normal conditions and sacrificed at the 8th week. Serum 25(OH)D₃ level decreased in F1 Early-VDD at the 8th week and returned to normal at the 18th week. Serum 25(OH)D₃ level in F2 Early-VDD at the 8th week was also lower than that in control rats. Impaired glucose tolerance was observed in F1 Early-VDD at the 8th week and 18th week and also in F2 Early-VDD at the 8th week. The gut microbiota composition in F1 Early-VDD at the 8th week significantly changed. Among the top ten genera with a rich difference, Desulfovibrio, Roseburia, Ruminiclostridium, Lachnoclostridium, A2, GCA-900066575, Peptococcus, Lachnospiraceae_FCS020_ group, and Bilophila increased owing to vitamin D deficiency, whereas Blautia decreased. There were 108 significantly changed metabolites in F1 Early-VDD at the 8th week, of which 63 were enriched in known metabolic pathways. Correlations between gut microbiota and metabolites were analyzed. Blautia was positively related to 2-picolinic acid, whereas Bilophila was negatively related to indoleacetic acid. Moreover, some of the changes in microbiota, metabolites, and enriched metabolic pathways still existed in F1 Early-VDD rats at the 18th week and F2 Early-VDD rats at the 8th week. In conclusion, vitamin D deficiency in early life leads to impaired glucose tolerance in adult and offspring rats. This effect may be partly achieved by regulating gut microbiota and their co-metabolites.

Sarcopenia in youth

Recent research has revealed causes other than aging that may induce sarcopenia in young people, contrary to the long-studied age-dependent reduction in muscular mass and function. The risk of sarcopenia begins in early adulthood, resulting in exaggerated muscle dysfunction in later life. Despite its clinical significance, research on youth-onset sarcopenia is still in its infancy. Due to a paucity of epidemiologic data and standardized criteria for sarcopenia in youth, determining the prevalence of sarcopenia in the young population remains challenging. Based on the evidence, >1 in every 10 young adults of most ethnicities is estimated to have sarcopenia. This review summarizes the possible etiologies of sarcopenia in young populations, including metabolic syndrome, physical inactivity, inadequate nutrition, inherent and perinatal factors, vitamin D deficiency, endocrinopathy, an imbalance of gut microbiota, neuromuscular diseases, organ failure, malignancy, and other inflammatory disorders. This is the first review of the current knowledge on the importance, prevalence, diagnosis, and causes of sarcopenia in youth.

Vitamin D status in children and its association with glucose metabolism in northern China: a combination of a cross-sectional and retrospective study

OBJECTIVES

This study aimed to explore the vitamin D status of children in northern China and the association between vitamin D and glucose metabolism.

DESIGN

Cross-sectional study was conducted among child participants and retrospective study designs were conducted among adult participants.

SETTING AND PARTICIPANTS

Both studies were recruited from Harbin, 326 children were included in children's study, 8469 adults were included in adult study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Physical examination, lifestyle and dietary habit data were recorded in all the participants. Serum insulin, glucose, 25(OH)D₃ concentrations in children and serum glucose and lipids levels in adults were measured. Rickets history was also investigated in adults, which was used to define vitamin D deficiency in childhood. The associations were tested by linear regression and binary logistic regression.

RESULT

In the children's study, only 10.7% of participants were vitamin D sufficient (≥30 ng/mL). Inverse correlations between serum 25(OH)D₃ concentration and fasting insulin and homeostasis model assessment - insulin resistance (HOMA-IR) were found, and children with lower serum 25(OH)D₃ concentrations were likely to have insulin resistance (IR) (OR: 0.955, 95% CI: 0.917 to 0.995, p value: 0.027). In an adult study, rickets in childhood increased the risk of type 2 diabetes in male participants (OR=1.414, 95% CI=1.013 to 1.972; p value=0.042), but this result was not observed in female participants.

CONCLUSION

Our findings suggest that vitamin D deficiency is widespread in northern China. Vitamin D deficiency in childhood was associated with IR and increased the risk of type 2 diabetes in male adults.

Correlation between Maternal Vitamin D and Thyroid Function in Pregnancy with Maternal and Neonatal Outcomes: A Cross-Sectional Study

BACKGROUND

The aim of this study was to evaluate the prevalence of vitamin D deficiency in pregnant women to investigate the relationship between vitamin D level and thyroid function.

METHODS

In this cross-sectional descriptive study, a total number of 66 patients during the three trimesters of pregnancy were investigated; 22 pregnant women were studied in each trimester of pregnancy. We evaluated thyroid function tests and thyroid autoantibodies (TPOAb and TGAb), as well as the serum level of 25OHD, to determine the relationship between vitamin D level and autoimmune or non-autoimmune thyroid disease in pregnancy.

RESULTS

Pearson's correlation in all subjects showed that vitamin D levels did not have a significant relationship with maternal age. Only in the third trimester, there was a significant difference in maternal age based on their vitamin D status. There was no significant difference between the trimesters of pregnancy and vitamin D status (P > 0.05). Also, there were no significant differences between serum levels of vitamin D within three trimesters. Examination of thyroid function tests during pregnancy in relation to vitamin D showed that there was no significant Spearman's correlation between thyroid function status and serum vitamin D level (P > 0.05). There was no significant difference in the mean level of serum 25OH vitamin D in each subgroup of thyroid status (P > 0.05). Regarding the pregnancy outcomes, two newborns were admitted to NICU, meconium aspiration was in one case, and IUFD in another case led to pregnancy termination. These four cases were related to the maternal history of hypothyroidism.

CONCLUSION

There was no significant relationship between vitamin D and pregnancy trimester. The serum level of vitamin D had no particular effect on the outcome of pregnancy and the thyroid gland function.

Assessment of the Relationship Between CD34 Antigen and Vitamin D Level and Insulin Resistance in Patients With Type 2 Diabetes

Diabetes causes disorders in the performance of endothelial progenitor cells, and obesity and vitamin D deficiency are associated with endothelial dysfunction and cardiovascular disease. This case-control study investigated the relationship between serum CD34 antigen and vitamin D levels and insulin resistance in type 2 diabetes. The results showed that CD34 has a significant inverse relationship with BMI, A1C, fasting blood glucose, insulin resistance, and insulin levels and has a significant direct relationship with vitamin D levels. Both CD34 and vitamin D were found to be significantly associated with type 2 diabetes. The association between reduced CD34 and vitamin D levels with type 2 diabetes and increased insulin resistance suggests that these parameters may be helpful in assessing diabetes and predicting its complications.

Vitamin D, rickets and child abuse: controversies and evidence

Suboptimal vitamin D status is a global health issue that affects children and adults worldwide. The prevalence of vitamin D deficiency and insufficiency has been well documented in the pediatric population in the United States. Although vitamin D deficiency is common, radiographic findings are uncommon and can be subtle. Additionally, because of the high prevalence of pediatric vitamin D insufficiency, it is commonly identified in young children with fractures. However, the majority of pediatric fractures are caused by trauma to healthy bones. Some, especially in infants and toddlers, are caused by non-accidental trauma. A small percentage is related to medical disease, including those associated with disorders of collagen, disorders of mineralization, and non-fracture mimics. Despite the scientific evidence, among disorders of mineralization, non-rachitic disorders of vitamin D have become a popular non-scientific theory to explain the fractures identified in abused children. Although infants and young children with rickets can fracture bones, the vast majority of fractures identified in abused infants are not caused by bone disease. Here we present a review of the literature on bone disease in the setting of accidental and non-accidental trauma. This context can help physicians remain vigilant about identifying vulnerable young children whose injuries are caused by non-accidental trauma.

Adolescent Athlete Stress Fractures Associated with Vitamin D Insufficiency: Three Cases with Review of the Literature

CASE

The authors present 3 adolescent athletes who presented with stress fractures in their lower extremities, initially diagnosed as tumors. All 3 patients received an inconclusive magnetic resonance imaging before referral; fractures were confirmed on radiographs and computed tomography. All were found to have vitamin D insufficiency.

CONCLUSIONS

Vitamin D insufficiency is a global epidemic mainly focused on adults and young-adult athletes. These case reports raise concerns about a growing prevalence of vitamin D insufficiency in adolescents, the potential risk of stress fracture, and the need for screening and possible supplementation in adolescent athletes to improve their bone health.

Association between Vitamin D Levels and Fertility Outcomes in Patients Undergoing IVF/ICSI

Background: Several studies have demonstrated that vitamin D (vitD) might play an important role in the reproductive system due to expression of vitD receptor and vitD-metabolizing enzymes in many reproductive tissues. VitD deficiency has been associated with increased risk of obstetric complications. However, the effect of vitD levels on in vitro fertilization (IVF)/ICSI outcomes is not fully understood. Evidence shows that women with adequate vitD levels might have higher pregnancy rates. This study evaluated the association between serum vitD levels and IVF/ICSI outcomes.

Methods: This multicenter, retrospective cohort study was conducted at IVFMD, My Duc Hospital and IVFMDPN, My Duc Phu Nhuan Hospital, Ho Chi Minh City, Vietnam between November 2017 and July 2019. Vietnamese patients aged 18–40 years with serum vitD (25(OH)D) samples collected before starting controlled ovarian stimulation and undergoing embryo transfer were eligible. Patients were divided into four groups based on 25(OH)D levels: <10 ng/mL, 10 to <20 ng/mL, 20 to <30 ng/mL, and [Formula: see text]30 ng/mL. The primary outcome was ongoing pregnancy rate.

Results: Of 3779 patients recruited, 25(OH)D levels were <10 ng/mL in 564 (14.9%), 10 to <20 ng/mL in 436 (11.5%), 20 to <30 in 1,142 (30.2%), and [Formula: see text]30 ng/mL in 1,637 (43.3%). Ongoing pregnancy rates were similar across the four subgroups (36%, 40%, 36%, and 36%, respectively; p = 0.409). The number of oocytes retrieved, embryos, clinical pregnancy, implantation, and miscarriage rates did not differ significantly between subgroups.

Conclusions: In this analysis, serum vitD levels did not appear to be correlated with pregnancy outcomes in patients undergoing IVF/ICSI.

The Impact of Vitamin D Levels in Foot and Ankle Surgery

Hypovitaminosis D has been established as a global health problem. As an important regulator of skeletal health homeostasis throughout one's life, optimal levels are presumed. Debate, however, still exists surrounding the definition of normal vitamin D levels and what affect hypovitaminosis D has on fracture prevention, fracture healing, and successful arthrodesis. A literature search failed to show any level 1 studies examining hypovitaminosis D and union rates in foot and/or ankle arthrodesis procedures. Several retrospective studies do point to some sort of association between nonunion and hypovitaminosis D. Because of lack of high-level studies, a potential study design is proposed.

Sunlight, UV Radiation, Vitamin D, and Skin Cancer: How Much Sunlight Do We Need?

Vitamin D is the sunshine vitamin for good reason. During exposure to sunlight, the ultraviolet B photons enter the skin and photolyze 7-dehydrocholesterol to previtamin D₃ which in turn is isomerized by the body's temperature to vitamin D₃. Most humans have depended on sun for their vitamin D requirement. Skin pigment, sunscreen use, aging, time of day, season, and latitude dramatically affect previtamin D₃ synthesis. Vitamin D deficiency was thought to have been conquered, but it is now recognized that more than 50% of the world's population is at risk for vitamin D deficiency. This deficiency is in part due to the inadequate fortification of foods with vitamin D and the misconception that a healthy diet contains an adequate amount of vitamin D. Vitamin D deficiency causes growth retardation and rickets in children and will precipitate and exacerbate osteopenia, osteoporosis and increase risk of fracture in adults. The vitamin D deficiency pandemic has other serious consequences including increased risk of common cancers, autoimmune diseases, infectious diseases, and cardiovascular disease. There needs to be a renewed appreciation of the beneficial effect of moderate sensible sunlight for providing all humans with their vitamin D requirement for health.

Chances of live birth after exposure to vitamin D-fortified margarine in women with fertility problems: results from a Danish population-based cohort study

OBJECTIVE

To study the association between extra vitamin D from a mandatory margarine fortification program and chance of live birth among infertile women.

DESIGN

Nationwide cohort study.

SETTING

Not applicable.

PATIENT(S)

The study population consisted of 16,212 women diagnosed with infertility from June 1, 1980, to August 31, 1991.

INTERVENTIONS(S)

We took advantage of the mandatory vitamin D fortification program of margarine in Denmark that was abruptly stopped on May 31, 1985. The termination of the vitamin D fortification served as a cutoff point to separate the study population into various exposure groups.

MAIN OUTCOME MEASURE(S)

Odds ratios and 95% confidence intervals for the association between vitamin D exposure status and chance of a live birth within 12, 15, and 18 months after first infertility diagnosis.

RESULT(S)

Women who were diagnosed with infertility during the vitamin D-exposed period had an increased chance of a live birth compared with women diagnosed with infertility during the nonexposed period. For women diagnosed with infertility during the wash-out period, the chance of a live birth was also increased, but somewhat lower. Similar estimates were obtained with longer follow-up, in women with anovulatory infertility, and little seasonal variation was observed when calendar period of conception was applied.

CONCLUSION(S)

Our findings suggest that infertile women exposed to extra vitamin D from a margarine fortification program had an increased chance of live birth compared with women not exposed to extra vitamin D from fortification.

Effect of vitamin D status on normal fertilization rate following in vitro fertilization

BACKGROUND

Vitamin D plays critical role in the female reproductive system. It seems that vitamin D is associated with clinical pregnancy outcomes of assisted reproductive technologies (ART), but its role remains elusive. This study is aimed to establish whether vitamin D is associated with clinical outcomes of in vitro fertilization (IVF).

METHODS

The cross-sectional study was carried out from January 1st 2017 to December 31st 2017. A total of 848 patients who had indications for IVF were enrolled. The patients were classified by serum 25 (OH) D quartiles. The outcome parameters of IVF were compared in each group, including normal fertilization rate, high quality embryo rate, clinical pregnancy rate, implantation rate and live birth rate.

RESULTS

The median 25 (OH) D concentration was 15.25 ng/ml. Serum 25 (OH) D levels in women varied with the seasons. We found that serum 25 (OH) D levels were higher in autumn than other seasons, and the lowest level occurred in spring. Follicular fluid (FF) vitamin D levels were positively correlated with serum vitamin D levels (r = 0.85, P < 0.001). The levels of FF vitamin D were significantly higher than the levels of serum vitamin D (P < 0.001). Normal fertilization rates were significantly different among four groups (P = 0.007). The group of women with the highest serum 25 (OH) D levels had the highest normal fertilization rate. However, the clinical pregnancy rate, implantation rate and live birth rates were not significantly different among the four groups when the age, BMI, AMH, seasons of blood drawing, COH protocol, high quality embryo rate and number of embryos transferred were adjusted. In addition, we found that serum 25 (OH) D levels were significantly higher in patients received IVF than patients received R-ICSI (P = 0.013).

CONCLUSIONS

Among Chinese women, lower serum vitamin D levels are associated with a lower fertilization rate in IVF. However, vitamin D level was not associated with the clinical pregnancy and live birth rate following IVF.

Vitamin D and assisted reproductive treatment outcome: a prospective cohort study

Background

Vitamin D deficiency has been associated with an increased risk of abnormal pregnancy implantation leading to obstetric complications such as pre-eclampsia and fetal growth restriction. However, the effect of vitamin D on reproductive treatment outcomes in couples undergoing assisted reproductive treatment is poorly understood. This study investigates the association between vitamin D and reproductive treatment outcomes in women undergoing assisted reproductive treatments?

Methods

A prospective cohort study conducted at a large tertiary teaching hospital, United Kingdom. Five hundred women undergoing assisted reproductive treatment were recruited between September 2013 and September 2015. All participants had their serum vitamin D measured and their reproductive treatment outcomes collated. Women were categorised in to three groups: vitamin D replete (> 75 nmol/L), insufficient (50-75 nmol/L) and deficient (< 50 nmol/L) according to Endocrine Society guidance. The primary outcome was live birth. Secondary outcomes included biochemical pregnancy, clinical pregnancy and pregnancy loss rates.

Results

Vitamin D deficiency was found in 53.2% (266/500) of participants and vitamin D insufficiency was found in 30.8% (154/500) of participants. Only 16% (80/500) of women were vitamin D replete. The live birth rates for vitamin D deficient, insufficient and replete women were 23.2% (57/246), 27.0% (38/141) and 37.7% (29/77) respectively (p = 0.04). The respective live birth rates for vitamin D deficient, insufficient and replete women were 24.3, 27.1, 34.4% after adjustment for key prognostic factors (p = 0.25).

Conclusions

Vitamin D deficiency and insufficiency are common in women undergoing assisted reproductive treatments. The crude live birth rate achieved in women undergoing assisted reproductive treatments are associated with serum vitamin D, although statistical significance is lost when adjusting for important prognostic variables. Vitamin D deficiency could be an important condition to treat in women considering fertility treatment. A research trial to investigate the benefits of vitamin D deficiency treatment would test this hypothesis.

Trial registration

Clinicaltrials.gov - NCT02187146.

Electronic supplementary material

The online version of this article (10.1186/s12978-019-0769-7) contains supplementary material, which is available to authorized users.

Vitamin D deficiency and its associated risk factors in normal adult population of Birjand, Iran

BACKGROUND

Vitamin D is required for calcium absorption, bone growth, and regulation of the immune system. Geographical location determines the intensity of the solar ultraviolet (UV) light as a significant determinant of vitamin D status in the many studies. This study was conducted to determine the status of vitamin D deficiency and its associated factors in adults of Birjand city, Iran (latitude: 32.87; longitude: 59.22).

METHODS

This descriptive-analytic study was performed by random stratified sampling on 400 subjects over 40 years of age in Birjand, who signed the consent form for participation. Data were collected in winter within one month from eight municipal health centers. Information regarding demographic characteristics, blood pressure, and anthropometric indices were collected, and blood samples were collected to measure 25-hydroxyvitamin D concentration.

RESULTS

The mean serum concentration of 25-OHD was 45.4 nmol/L. Twenty-six percent of subjects had vitamin D deficiency, 45.2% had insufficiency, and 28.8% of the subjects were healthy. The results of the multiple logistic regression showed that age (OR: 0.92, 95% CI = 0.89-0.96) and serum calcium concentration (OR: 0.52, 95% CI = 0.28-0.94) had a significant correlation with 25-OHD deficiency.

CONCLUSION

A high percentage of adults in the city of Birjand are suffering from vitamin D deficiency, which implies a need for extensive training and food enrichment programs, promoting healthy lifestyles, and exercise and walking.

Quantitation of serum 25(OH)D2 and 25(OH)D3 concentrations by liquid chromatography tandem mass spectrometry in patients with diabetes mellitus

Vitamin D has been considered to regulate calcium and phosphorus homeostasis and to preserve skeletal integrity. Serum 25-hydroxyvitamin D (25(OH)D) is the best indicator of vitamin D levels. The association of serum 25(OH)D deficiency with increased risk of type 1 diabetes (T1DM) and type 2 diabetes (T2DM) is controversial. We investigated serum 25(OH) D₂ and 25(OH)D₃ levels in diabetes patients by using liquid chromatography tandem mass spectrometry (LC-MS/MS). Serum 25(OH)D2 and 25(OH)D3 levels were measured with liquid chromatography tandem mass spectrometry in electrospray ionization positive mode. Chromatograms were separated using an ACE5 C18 column on a gradient of methanol. The total 25(OH)D levels were calculated as the sum of 25(OH)D3 and 25(OH)D2 levels. A total of 56 patients with T1DM and 41 patients with T2DM were enrolled in this study. There were 42 and 28 non-diabetic, age-matched volunteers who participated as the T1DM controls and the T2DM controls, respectively. The total 25(OH)D levels were lowest in the 21–40 age group. The levels of both 25(OH)D3 and the total 25(OH)D were significantly higher in the T1DM and T2DM groups than in the controls (p < 0.01 in T1DM and p < 0.05 in T2DM group, respectively). The 25(OH)D2 levels were only significantly higher in T1DM patients than in the controls. The percentages of vitamin D deficiency (total 25(OH)D less than 20 ng/mL) in the T1DM, T2DM, the T1DM controls and the T2DM controls were 7.1%, 0%, 14.3% and 3.6%, respectively. The percentages of vitamin D insufficiency (total 25(OH)D less than 30 ng/mL) in the T1DM, T2DM, the T1DM controls and the T2DM controls were 26.8%, 7.3%, 54.8% and 17.9%, respectively. The percentages of vitamin D deficiency and insufficiency were significantly lower in the T1DM patients than in the T1DM controls (p < 0.01). In the present study, both type 1 and type 2 diabetes patients had higher serum 25(OH)D levels and lower percentages of vitamin D deficiency/insufficiency.

The Role of Vitamin D in the Pathogenesis of Adolescent Idiopathic Scoliosis

Several theories have been proposed to explain the etiology of adolescent idiopathic scoliosis (AIS) until present. However, limited data are available regarding the impact of vitamin D insufficiency or deficiency on scoliosis. Previous studies have shown that vitamin D deficiency and insufficiency are prevalent in adolescents, including AIS patients. A series of studies conducted in Hong Kong have shown that as many as 30% of these patients have osteopenia. The 25-hydroxyvitamin D3 level has been found to positively correlate with bone mineral density (BMD) in healthy adolescents and negatively with Cobb angle in AIS patients; therefore, vitamin D deficiency is believed to play a role in AIS pathogenesis. This study attempts to review the relevant literature on AIS etiology to examine the association of vitamin D and various current theories. Our review suggested that vitamin D deficiency is associated with several current etiological theories of AIS. We postulate that vitamin D deficiency and/or insufficiency affects AIS development by its effect on the regulation of fibrosis, postural control, and BMD. Subclinical deficiency of vitamin K2, a fat-soluble vitamin, is also prevalent in adolescents; therefore, it is possible that the high prevalence of vitamin D deficiency is related to decreased fat intake. Further studies are required to elucidate the possible role of vitamin D in the pathogenesis and clinical management of AIS.

Prevalence of vitamin D deficiency in Iran: A systematic review and meta-analysis

BACKGROUND

The prevalence of vitamin D deficiency in the Iranian community is very high. Women and older people are at the higher risk of vitamin D deficiency.

AIM

This study aimed to estimate the prevalence of vitamin D deficiency in Iran by combining the results of various studies.

METHODS

This was a systematic review and meta-analysis. Separate strategies were developed for search in national databases (Irandoc, Magiran, SID) and international databases (Web of Science, PubMed, and Scopus) using the keywords of "vitamin D deficiency," "Iran," and "prevalence." The titles and abstracts of the articles were screened and related full texts were appraised. Those articles that met inclusion criteria were selected for meta-analysis. The heterogeneity of the articles was assessed via the Chi-square test. They were combined using the random-effect approach. In addition, the groups were categorized and analyzed in terms of age and gender.

RESULTS

Of 639 articles, 30 articles with a sample size of 26,042 people were included for data analysis. The overall prevalence of vitamin D deficiency was reported as 0.56. Subgroup analysis showed that 0.64 of women and 0.44 of men were suffering from vitamin D deficiency. The prevalence of vitamin D deficiency in the age groups under 20, 20-50, and over 50 years was 0.56.4, 0.72.4, and 0.59.8, respectively.

CONCLUSIONS

The Iranian Ministry of Health is expected to design strategies to improve the status of vitamin D at the national level.

Vitamin D and orthodontics: an insight review

Vitamin D is known as the oldest of all hormones. 7-Dehydrocholesterol is converted to previtamin D₃. It becomes a secosteroid when it is later converted to 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃). A number of factors influence vitamin D₃ production, including skin pigmentation, the use of sunscreen lotions, season, latitude, and altitude. Vitamin D is important for bone metabolism and calcium hemostasis. Researchers have linked a deficiency in vitamin D levels to a number of systemic complications, including cardiovascular disease, diabetes, immune deficiency, and infectious diseases. In orthodontics, laboratory studies have revealed some evidence that vitamin D enhances tooth movement and the stability of the tooth position. This review is an attempt to understand the role and systemic consequences of vitamin D deficiency and to examine its relevance to orthodontics.

High Prevalence of Vitamin D Deficiency among Iranian Population: A Systematic Review and Meta-Analysis

BACKGROUND

The prevention and correction of vitamin D deficiency requires a precise depiction of the current situation and identification of risk factors in each region. The present study attempted to determine these entities using a systematic review and meta-analysis in Iran.

METHODS

Articles published online in Persian and English between 2000 and November 1, 2016, were reviewed. This was carried out using national databases such as SID, IranMedex, Magiran, and IranDoc and international databases such as PubMed, Google Scholar, and Scopus. The heterogeneity index among the studies was determined using the Cochran (Q) and I² test. Based on the heterogeneity results, the random-effect model was applied to estimate the prevalence of vitamin D deficiency. In addition, meta-regression analysis was used to determine heterogeneity-suspected factors, and the Egger test was applied to identify publication bias.

RESULTS

The meta-analysis of 48 studies identified 18531 individuals with vitamin D deficiency. According to the random-effect model, the prevalence of vitamin D deficiency among male, female, and pregnant women was estimated to be 45.64% (95% CI: 29.63 to 61.65), 61.90% (95% CI: 48.85 to 74.96), and 60.45% (95% CI: 23.73 to 97.16), respectively. The results of the meta-regression analysis indicated that the prevalence of vitamin D deficiency was significantly different in various geographical regions (β=4.4; P=0.023).

CONCLUSION

The results obtained showed a significant prevalence of vitamin D deficiency among the Iranian population, a condition to be addressed by appropriate planning.

Vitamin D levels and parathyroid hormone variations of children living in a subtropical climate: a data mining study

BACKGROUND

Vitamin D and intact parathyroid hormone (iPTH) play a crucial role in calcium homeostasis and bone health of children. Serum level of 25-hydroxyvitamin D (25-OHD) is considered to be the most accurate marker for vitamin D status. However, there have only been a few studies, with limited number of subjects, investigating the relationship between 25-OHD and parathyroid hormone (PTH) in children. The aim of this study was to evaluate the seasonal 25-OHD levels and its associations with intact parathyroid hormone (iPTH) in Turkish children at all pediatric ages; and then to define a critical decision threshold level for 25-OHD deficiency in Turkish children.

METHODS

A retrospective record review of 90,042 children, was performed on serum 25-OHD and for 3525 iPTH levels. They were measured by mass spectrometry method and by electrochemiluminescence immunoassay simultaneously.

RESULTS

25-OHD levels showed a sinusoidal fluctuation througout the year; being significantly higher in summer and autumn (p < 0,01). 25-OHD levels decreased with respect to age. The significant inverse relationship that was found between iPTH and 25-OHD suggests that the inflection point of serum 25-OHD level for maximal suppression of PTH is at 30 ng/ml.

CONCLUSION

As the rate of vitamin D deficiency decreases in the early years due to vitamin D supplementation, the recommendation should be set due to a clinical threshold level of 30 ng/ml for 25-OHD based on PTH levels in children of our population.

Prevalence of Vitamin D Deficiency in Pediatric Patients With Scoliosis Preparing for Spinal Surgery

BACKGROUND

Establishing prevalence of vitamin D deficiency in elective scoliosis surgery may impact clinical outcomes. The objectives of this study were to document vitamin D status of patients with scoliosis preparing for surgical intervention in order to establish frequency of deficiency and determine characteristics influencing levels.

METHODS

Records were queried for patients with scoliosis diagnosis who underwent posterior spinal fusion or initial growing rod placement and had serum vitamin 25 hydroxyvitamin D (D25) recorded in the preoperative period. Demographic data (gender, age, body mass index [BMI], race, scoliosis type, spine surgery procedure, and season of the year) were extracted. Chi-square analysis and multivariate modeling were used to evaluate deficiency status among various demographic categories and determine the demographic factors impacting D25.

RESULTS

A total of 217 patients with a mean age of 13.6 ± 3.6 years had vitamin D levels drawn a mean of 38.7 ± 20.6 days prior to surgery. The majority of the sample presented with a diagnosis of idiopathic scoliosis (n = 126), and most patients were scheduled for spinal fusion surgery (n = 192). Nearly 75% of the study population (n = 162) demonstrated D25 values below normal. African Americans presented with greater risk of deficiency (p < .0002) compared to Caucasians, as did patients preparing for spinal fusion versus growing rod placement (p < .03). Severe hypovitaminosis D was more common in winter than any other season (p < .005). Patients with neuromuscular scoliosis demonstrated significantly higher D25 levels over the idiopathic diagnosis type (p < .0002). Gender, BMI, and age did not impact D25.

CONCLUSION

Low D25 levels are reported in pediatric patients with scoliosis preparing for corrective spinal surgery. Population subsets most at risk for deficiency in this limited study include African American children, those presenting for spinal fusion surgery, and patients admitted in winter season.

Prevalence of hypovitaminosis D and associated factors in obese Spanish children

Background/Objectives:

Vitamin D deficiency may contribute to endocrine health and disease (diabetes, autoimmune thyroid diseases, polycystic ovarian syndrome, etc.). The aim of this study was to determine the prevalence and specific factors for hypovitaminosis D among children stratified by body mass index (BMI) in Northern Spain.

Subjects/Methods:

A cross-sectional clinical (sex, age, season of study visit, place of residence and BMI) and blood testing (calcium, phosphorous, calcidiol and parathyroid hormone (PTH)) were accomplished in 546 Caucasian individuals (aged 3.2–15.8 years). The BMI (Z-score) allowed establishing four groups: normal, overweight, obesity and severe obesity. The criteria of the US Endocrine Society were used for the definition of hypovitaminosis D.

Results:

Calcidiol levels were significantly higher in normal and overweight groups (P=0.001), whereas PTH levels were significantly higher in obesity and severe obesity groups (P=0.001). Hypovitaminosis D prevalence was significantly higher in severe obesity (81.1%) and obesity (68.2%) groups, whereas was lowest in overweight (55%) and normal (58.1%) groups (P=0.001). There was a negative correlation between calcidiol and PTH levels (P<0.01). Female (90.9%), adolescent group (88,2%), winter (100%) and autumn (82.4%) time and urban residence (94.1%) imply a higher prevalence of hypovitaminosis D in subjects with severe obesity (P<0.001). Female, puberal age, autumn, winter and spring time, urban residence and severe obesity were found to be independent predictors for hypovitaminosis D.

Conclusions:

Severe obesity could be considered as an associated factor for vitamin D deficiency, and, owing to its high prevalence, the implementation of systematic screening and hypovitaminosis treatment programs would be particularly useful.

Vitamin D status of Icelandic children and its influence on bone accrual

The importance of vitamin D for children's bone health has been well established, but the effects of less severe deficiency are not fully known. The main objective of this study was to assess the vitamin D status of Icelandic children at the age of 7, and again at 9 years of age, and the association of vitamin D status with bone mineral content and bone accrual over 2 years. We invited 321 children to participate in this study, and 267 (83 %) took part; 211 (79 %) underwent a DXA scan and 164 were again scanned 2 years later; 159 (60 %) vitamin D samples were measured and 119 (75 %) were measured again 2 years later. At age 7, 65 % of the children had vitamin D concentrations <50 nmol/l, and at age 9 this figure was 60 %. At age 7, 43 % of the children had insufficient amounts of vitamin D (37.5-50 nmol/l), and 22 % had a vitamin D deficiency (<37.5 nmol/l). In linear regression analysis, no association was found between vitamin D and bone mineral content. Furthermore, there was no significant difference in bone accrual over 2 years for the children with insufficient or deficient vitamin D at both ages, compared to those having more than 50 nmol/l at both time points. More than 60 % of Icelandic children have inadequate concentrations of vitamin D in serum repeatedly over a 2-year interval. However, vitamin D in the range did not have a significant effect on bone mineral content or accrual at ages 7 and 9.

Economic Benefit of Calcium and Vitamin D Supplementation: Does It Outweigh the Cost of Nonunions?

OBJECTIVES

The purpose was to evaluate economic benefit of calcium and vitamin D supplementation in orthopaedic trauma patients. We hypothesized that reduced nonunion rates could justify the cost of supplementing every orthopaedic trauma patient.

DESIGN

Retrospective, economic model.

SETTING

Level 1 trauma center.

PATIENTS/PARTICIPANTS

Adult patients over 3 consecutive years presenting with acute fracture.

INTERVENTION

Operative or nonoperative fracture management.

MAIN OUTCOME MEASUREMENTS

Electronic medical records were queried for ICD-9 code for diagnosis of nonunion and for treatment records of nonunion for fractures initially treated within our institution.

RESULTS

In our hospital, a mean of 92 (3.9%) fractures develop nonunion annually. A 5% reduction in nonunion risk from 8 weeks of vitamin D supplementation would result in 4.6 fewer nonunions per year. The mean estimate of cost for nonunion care is $16,941. Thus, the projected reduction in nonunions after supplementation with vitamin D and calcium would save $78,030 in treatment costs per year. The resulting savings outweigh the $12,164 cost of supplementing all fracture patients during the first 8 weeks of fracture healing resulting in a net savings of $65,866 per year.

CONCLUSIONS

Vitamin D and calcium supplementation of orthopaedic trauma patients for 8 weeks after fracture seems to be cost effective. Supplementation may also reduce the number of subsequent fractures, enhance muscular strength, improve balance in the elderly, elevate mood leading to higher functional outcome scores, and diminish hospital tort liability by reducing the number of nonunions.

LEVEL OF EVIDENCE

Economic Level V. See Instructions for Authors for a complete description of levels of evidence.

Sun-Exposed Skin Color Is Associated with Changes in Serum 25-Hydroxyvitamin D in Racially/Ethnically Diverse Children

BACKGROUND

UVB light from the sun increases serum 25-hydroxyvitamin D [25(OH)D] concentration, but this relation may depend on skin pigmentation among different racial/ethnic groups.

OBJECTIVE

We used quantitative measures of exposed (facultative) and unexposed (constitutive) skin color to examine relations between serum 25(OH)D concentration, tanning, race/ethnicity, and constitutive skin color over the summer, following winter vitamin D supplementation.

METHODS

The subjects (n= 426, mean age 11.7 ± 1.4 y, 51% female) were racially/ethnically diverse schoolchildren (57% non-white/Caucasian) enrolled in a 6-mo vitamin D supplementation trial (October-December to April-June). In this secondary analysis, measures of serum 25(OH)D concentration and skin color, with the use of reflectance colorimetry, were taken over a 6-mo period after supplementation, from pre-summer (April-June) to post-summer (September-December). Multiple linear regression was used to evaluate longitudinal relations.

RESULTS

Following supplementation, mean serum 25(OH)D concentration was 29.3 ± 9.5 ng/mL but fell to 25.6 ± 7.9 ng/mL (P< 0.0001) by the end of summer. The decrease in white/Caucasian children was less than in black/African American children (P< 0.01) and tended to be less than in Hispanic/Latino, Asian, and multiracial/other children (P= 0.19-0.50) despite similar changes in sun-exposed skin color among all groups. Tanning was significantly associated with post-summer serum 25(OH)D concentration (β = -0.15,P< 0.0001), as was race/ethnicity (P= 0.0002), but the later association disappeared after adjusting for constitutive skin color.

CONCLUSIONS

Tanning significantly contributed to serum 25(OH)D concentration over the summer, independent of race/ethnicity, but was not sufficient to maintain serum 25(OH)D concentration attained with supplementation. Much of the variation in serum 25(OH)D concentration between racial/ethnic groups may be explained by skin color. This trial was registered atclinicaltrials.govasNCT01537809.

Study of the Vitamin D Levels in Patients Referred to Clinical Laboratories in Mashhad in 2015 and their Relationship with the Patients' Lipid Profiles

INTRODUCTION

Vitamin D is a steroid hormone that has a significant role in the metabolism of minerals, especially calcium and phosphorus; it also is a major determinant of the strength of bones. This hormone has a significant effect on three major health issues that people worldwide encounter, i.e., high blood pressure, cancer, and diabetes. Considering the limited and dispersed studies on the prevalence of vitamin D deficiency in Iran and the relationship of vitamin D with lipid profiles in different people, this study was conducted to determine the vitamin D levels in patients and its relationship with their lipid profiles.

METHODS

A retrospective cross-sectional study was conducted in 2015 on 1,110 patients who were referred to the two laboratories at Jihad Daneshgahi and to eight specialist laboratories in Mashhad through random sampling of patients for whom serum vitamin D and serum lipid tests were prescribed. The data that were obtained were entered into SPSS 13 software.

RESULTS

Sixty-eight percent of the patients in the study were deficient in vitamin D. The vitamin D levels in males were significantly lower than those in females (p < 0.05). The relationship between age and vitamin D deficiency was significant as well (p < 0.05). A positive and significant relationship was observed between age and vitamin D deficiency (p = 0.000, r = 0.187), i.e., vitamin D deficiency was more apparent in patients whose ages were in the range of 40-59. The relationship between the levels of vitamin D and serum lipids was significant and positive (p = 0.05), with the exception of LDL.

CONCLUSION

About two-thirds of the population that was studied had a vitamin D deficiency. There was a positive and significant relationship between serum vitamin D and serum lipids and serum calcium. The results of this study showed the necessity for more research and the implementation of preventive measures related to vitamin D deficiency. It is recommended that vitamin D enrichment programs be planned and implemented.

Association of Vitamin D Levels With Outcome in Patients With Melanoma After Adjustment For C-Reactive Protein

PURPOSE

To evaluate for an association between 25-hydroxyvitamin D levels (vitamin D) and outcome measures in patients with melanoma after evaluation is controlled for systemic inflammatory response (SIR) on the basis of simultaneous C-reactive protein (CRP) measurement.

MATERIALS AND METHODS

Plasma samples from 1,042 prospectively observed patients with melanoma were assayed for vitamin D and CRP. The associations of demographics and CRP with vitamin D were determined, followed by a determination of the association between vitamin D and stage and outcome measures from the date of blood draw. The vitamin D level was considered sufficient if it was 30 to 100 ng/mL. Kaplan-Meier and Cox regression analyses were performed.

RESULTS

The median vitamin D level was 25.0 ng/mL. The median follow-up time was 7.1 years. A lower vitamin D was associated with the blood draw during fall/winter months (P < .001), older age (P = .001), increased CRP (P < .001), increased tumor thickness (P < .001), ulcerated tumor (P = .0105), and advanced melanoma stage (P = .0024). On univariate analysis, lower vitamin D was associated with poorer overall (OS; P < .001), melanoma-specific survival (MSS; P = .0025), and disease-free survival (DFS; P = .0466). The effect of vitamin D on these outcome measures persisted after adjustment for CRP and other covariates. Multivariable hazards ratios per unit decrease of vitamin D were 1.02 for OS (95% CI, 1.01 to 1.04; P = .0051), 1.02 for MSS (95% CI, 1.00 to 1.04; P = .048), and 1.02 for DFS (95% CI, 1.00 to 1.04; P = .0427).

CONCLUSION

Lower vitamin D levels in patients with melanoma were associated with poorer outcomes. Although lower vitamin D was strongly associated with higher CRP, the associations of lower vitamin D with poorer OS, MSS, and DFS were independent of this association. Investigation of mechanisms responsible for these associations may be of value to patients with melanoma.

Role of vitamin D in diabetes mellitus and chronic kidney disease

Approximately 30%-50% of people are recognized to have low levels of vitamin D, and insufficiency and deficiency of vitamin D are recognized as global health problems worldwide. Although the presence of hypovitamin D increases the risk of rickets and fractures, low vitamin D levels are also associated with hypertension, cancer, and cardiovascular disease. In addition, diabetes mellitus (DM) and chronic kidney disease (CKD) are also related to vitamin D levels. Vitamin D deficiency has been linked to onset and progression of DM. Although in patients with DM the relationship between vitamin D and insulin secretion, insulin resistance, and β-cell dysfunction are pointed out, evidence regarding vitamin D levels and DM is contradictory, and well controlled studies are needed. In addition, vitamin D influences the renin-angiotensin system, inflammation, and mineral bone disease, which may be associated with the cause and progression CKD. There is increasing evidence that vitamin D deficiency may be a risk factor for DM and CKD; however, it remains uncertain whether vitamin D deficiency also predisposes to death from DM and CKD. Although at this time, supplementation with vitamin D has not been shown to improve glycemic control or prevent incident DM, clinical trials with sufficient sample size, study periods, and optimal doses of vitamin D supplementation are still needed. This review focuses on the mechanism of vitamin D insufficiency and deficiency in DM or CKD, and discusses the current evidence regarding supplementation with vitamin D in patients with these diseases.

Seasonal variations in calcidiol and parathyroid hormone levels in healthy children and adolescents in Navarre, Spain: a cross-sectional study

Objective

To analyze the seasonal variations in calcidiol and parathyroid hormone serum levels along a natural year in a paediatric population living in a region of the north of Spain considering a normal nutrition status.

Design

A cross-sectional study.

Setting

Navarra Hospital Complex, Pamplona, Spain.

Participants

A total of 413 Caucasian individuals (aged 3.1 to 15.4 years): 227 school children (96 males and 131 females) and 186 adolescents (94 males and 92 females), with normal nutritional status.

Main outcome measures

Clinical examination (sex, age, weight, height and body mass index) and blood testing (calcium, phosphate, alkaline phosphatase, calcidiol and parathyroid hormone) during the year 2014.

Results

Calcidiol levels were lower during spring (25.96 ± 6.64 ng/mL) and reached its maximum level in summer (35.33 ± 7.51 ng/mL); parathyroid hormone levels were lower in summer (27.13 ± 7.89 pg/mL) and reached maximum level in autumn (34.73 ± 15.38 pg/mL). Hypovitaminosis D prevalence was 14.3% in summer and 75.3% in spring. Parathyroid hormone levels were compatible with secondary hyperparathyroidism in eight individuals (1.9%). There is a correlation (p < 0.01) between calcidiol and parathyroid hormone (r = −0.336). Logistic regression showed significant increased risk of hypovitaminosis in females (OR:1.63) and adolescents (OR:1.77), and when blood samples taken in autumn (OR:12.22), winter (OR:8.54) and spring (OR:19.72).

Conclusions

There is a high prevalence of hypovitaminosis D in the paediatric population with a healthy nutrition situation in Navarre, mainly during the months of autumn and winter, and, especially, in spring time. Given the difficulties in maintaining a sufficient amount of body vitamin D content along the year, it should be considered to give vitamin supplements and/or increase the intake of its natural dietary sources or vitamin D fortified foods.

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.

Low Vitamin D Levels in Children with Fractures: a Comparative Cohort Study

BACKGROUND

The currently accepted ranges for "normal" serum vitamin D have recently been challenged in adults on the basis that healthy bone metabolism requires higher levels of vitamin D than previously thought.

PURPOSE

The purpose of this study was to evaluate whether a new "biologically based" classification based on 25(OH)vitamin D levels that invoke an endocrine biomarker response (<20 ng/mL for deficiency and <32 ng/mL for insufficiency) is more appropriate for children with fractures than historical criteria.

METHODS

Serum 25(OH)vitamin D levels were collected from 58 children with acute low-energy fractures from an outpatient orthopedic clinic from 2009 to 2012. These vitamin D levels were compared with a cohort of 103 children with chronic kidney disease (CKD) from an adjacent clinic, a condition with acknowledged low levels of vitamin D. Then, the prevalence of vitamin D sufficiency in the fracture cohort was evaluated and compared using both historical guidelines and newer biologically based criteria.

RESULTS

25(OH)vitamin D levels in the fracture cohort did not differ from levels in the CKD cohort (27.5 vs. 24.6 ng/mL) indicating a similar distribution of vitamin D levels. This finding was consistent when controlling for significant covariables using linear regression analyses. In the fracture cohort, there was a discrepancy between historical and biologically based criteria in 64% of children.

CONCLUSIONS

The results of the current study suggest that fracture patients are more frequently vitamin D deficient than previously thought. This finding is more readily apparent when newer biologically based criteria for vitamin D sufficiency are used.

Resurgence of vitamin D: Old wine in new bottle

There are early references of it in ancient text and physicians have discussed its importance and features of its deficiency in the past. Vitamin D has again regained interest with recent dramatic rise in the incidence of deficiency in the developing as well as developing world. In this review article, we discuss the biochemical and role of vitamin D in the skeletal system. We also discuss the recommended dietary requirements and features of skeletal deficiency. Extra-skeletal roles of vitamin D deficiency have been a matter of debate lately and it has also been discussed in detail in this article. In conclusion, it would not be wrong to label vitamin D as one of the most important vitamin involved in the metabolism of the musculoskeletal system and any clinician, especially the orthopaedician, should be well versed with its overall mechanism and roles in the human body.

[Vitamin D supplementation: not too much, not too little!]

Vitamin D deficiency is common in the general population and even more frequent in patients with chronic diseases. The prevention of rickets with native vitamin D supplementation is one of the oldest and most effective prophylactic measures ever reported in medicine, leading to an almost complete eradication of vitamin D-deficient rickets in developed countries. We report on two children with vitamin D abnormalities: the first, 10-year-old child developed rickets without any vitamin D supplementation despite different risk factors (autism, ethnicity, nutritional problems, chronic antiepileptic therapies). In contrast, the second, 8-month-old child received double doses of native vitamin D from birth for several months and was referred for acute and symptomatic hypercalcemia. As such, vitamin D supplementation must follow specific rules: neither too much nor too little! We also discuss the emergence of "new" genetic diseases such as mutations in the 24-hydroxylase (CYP24A1) gene inducing neonatal hypercalcemia and nephrocalcinosis: we believe that before prescribing conventional vitamin D supplementation as recommended by the national guidelines, pediatricians should quickly rule out a potential genetic abnormality in phosphate/calcium metabolism (namely a history of lithiasis or hypercalcemia) that would lead to further biological investigations.

The role of vitamin D in psoriasis: a review

BACKGROUND AND OBJECTIVE

Psoriasis is a common, chronic autoimmune inflammatory skin disorder, which has potential systemic complications and is clinically defined by sharply demarcated, erythematous patches and plaques covered by a characteristic silvery white scale. Topical corticosteroids have widely been regarded as the mainstay first line of treatment. Recently, topical vitamin D analogs have been added to the first-line treatment repertoire as well, either as monotherapy or in combination with topical steroids due to synergistic, complementary effectiveness. In this paper, we review the role of vitamin D in the pathophysiology and treatment of psoriasis.

METHODS

A comprehensive search of the Cochrane Library, MEDLINE, and PUBMED databases were performed to identify relevant basic science and clinical trial literature investigating the role of vitamin D in psoriasis. Primary endpoints in clinical trials were largely based on clinical improvement as assessed by the psoriasis area severity index score or physician's global assessment.

RESULTS AND CONCLUSION

The role of vitamin D in psoriasis is complex and extensive. Oral and topical vitamin D therapies provide comparable efficacies to corticosteroids when used as monotherapy and may be superior when used in combination with a potent topical steroid. Additionally topical vitamin D analogs demonstrate a favorable safety profile with "steroid-sparing" effects. Thus, topical vitamin D derivatives should be considered an indispensable component of the current physician's arsenal in the treatment of psoriasis.

Serum 25 hydroxyvitamin D in employees of a Middle Eastern university hospital

BACKGROUND

The Middle East registers the highest rate of vitamin D deficiency worldwide. In Lebanon, previous studies looked at this deficiency in schoolchildren, university students, young adults and postmenopausal women. However, no previous study was performed in hospital workers. The objective of our study was to evaluate vitamin D status in a Beirut hospital center and to look at the potential factors influencing these measurements.

METHODS

This cross-sectional study was performed on hospital employees who came for a regular checkup at the primary health-care department. 25(OH)D measurements were performed using the Dia-Sorin chemiluminescent assay.

RESULTS

392 subjects (318 women and 74 men) were included in the study. The mean age of the participants was 41.02 ± 11.3 years. The mean 25(OH)D level was 15.61 ± 7.91 ng/ml, with no significant difference according to gender. There were no significant correlations between 25(OH)D and both BMI and age, but 25(OH)D was significantly associated with educational level (p = 0.03). There was a significant difference in 25(OH)D levels according to season (p < 0.001) and a significant association between 25(OH)D and the reported weekly hours of sun exposure (r = 0.1, p = 0.032), but not with the reported sunscreen use. Fish consumption was positively associated with 25(OH)D levels (p = 0.018), while milk, dairy product or egg consumption did not achieve any significant relationship. In a stepwise linear regression analysis, fish consumption and season were the only independent predictors of 25(OH)D levels (p = 0.007 and p = 0.0001 respectively).

CONCLUSION

Vitamin D deficiency is common among hospital workers. This finding reinforces the need for vitamin D supplementation in these high-risk populations.

Vitamin d deficiency in a multiethnic healthy control cohort and altered immune response in vitamin D deficient European-American healthy controls

Objective

In recent years, vitamin D has been shown to possess a wide range of immunomodulatory effects. Although there is extensive amount of research on vitamin D, we lack a comprehensive understanding of the prevalence of vitamin D deficiency or the mechanism by which vitamin D regulates the human immune system. This study examined the prevalence and correlates of vitamin D deficiency and the relationship between vitamin D and the immune system in healthy individuals.

Methods

Healthy individuals (n = 774) comprised of European-Americans (EA, n = 470), African–Americans (AA, n = 125), and Native Americans (NA, n = 179) were screened for 25-hydroxyvitamin D [25(OH)D] levels by ELISA. To identify the most noticeable effects of vitamin D on the immune system, 20 EA individuals with severely deficient (<11.3 ng/mL) and sufficient (>24.8 ng/mL) vitamin D levels were matched and selected for further analysis. Serum cytokine level measurement, immune cell phenotyping, and phosphoflow cytometry were performed.

Results

Vitamin D sufficiency was observed in 37.5% of the study cohort. By multivariate analysis, AA, NA, and females with a high body mass index (BMI, >30) demonstrate higher rates of vitamin D deficiency (p<0.05). Individuals with vitamin D deficiency had significantly higher levels of serum GM-CSF (p = 0.04), decreased circulating activated CD4⁺ (p = 0.04) and CD8⁺ T (p = 0.04) cell frequencies than individuals with sufficient vitamin D levels.

Conclusion

A large portion of healthy individuals have vitamin D deficiency. These individuals have altered T and B cell responses, indicating that the absence of sufficient vitamin D levels could result in undesirable cellular and molecular alterations ultimately contributing to immune dysregulation.

The association of vitamin D status with cardiometabolic risk factors, obesity and puberty in children

Low serum 25-hydroxyvitamin D3 (25(OH)D) levels have been associated with insulin resistance and cardiovascular diseases. The influences of gender, puberty and adiposity on vitamin D status and the relationship between 25(OH)D and cardiometabolic risk factors in obese and non-obese children were studied. A retrospective analysis was carried out on 168 Turkish children during late winter. Age, gender, puberty, body mass index (BMI), 25(OH)D levels and cardiometabolic risk factors including lipid profiles, high-sensitivity C-reactive protein and insulin resistance index calculated by homeostasis model assessment (HOMA-IR) were evaluated. The median age of the study population was 11 (4-16) years, and 102 children (60.7 %) were prepubertal. Overall, 98.2 % of patients had 25(OH)D levels lower than 20 ng/mL (median 10.0 (4.0-21.3) ng/mL). The 25(OH)D levels did not correlate with BMI. However, an inverse correlation was seen between serum 25(OH)D and HOMA-IR (rho = -0.656, p = 0.006) and insulin (rho = -0.715, p = 0.002) in pubertal obese subjects. Female gender and puberty were all negatively associated with 25(OH)D.

CONCLUSION

The association between vitamin D status and BMI is complex, and it does not seem to be altered by mild obesity. In addition, potential influence of puberty should be kept in mind while assessing the relationship between serum 25(OH)D and cardiometabolic risk factors.

Vitamin D supplementation in young White and African American women

There is limited information on the effects of vitamin D on serum 25 hydroxyvitamin D (25OHD) in young people and none on African Americans. The main objective of this trial was to measure the effect of different doses of vitamin D3 on serum 25OHD and serum parathyroid hormone (PTH) in young women with vitamin D insufficiency (serum 25OHD ≤ 20 ng/mL (50 nmol/L). A randomized double-blind placebo-controlled trial of vitamin D3 was conducted in young white and African American women, age 25 to 45 years. A total of 198 healthy white (60%) and African American (40%) women were randomly assigned to placebo, or to 400, 800, 1600, or 2400 IU of vitamin D3 daily. Calcium supplements were added to maintain a total calcium intake of 1000 to 1200 mg daily. The primary outcomes of the study were the final serum 25OHD and PTH levels at 12 months. The absolute increase in serum 25OHD with 400, 800, 1600, and 2400 IU of vitamin D daily was slightly greater in African American women than in white women. On the highest dose of 2400 IU/d, the mixed model predicted that mean 25OHD increased from baseline 12.4 ng/mL (95% confidence interval [CI], 9.2-15.7) to 43.2 ng/mL (95% CI, 38.2-48.1) in African American women and from 15.0 ng/mL (95% CI, 12.3-17.6) to 39.1 ng/mL (95% CI, 36.2-42.0) in white women. There was no significant effect of vitamin D dose on serum PTH in either race but there was a significant inverse relationship between final serum PTH and serum 25OHD. Serum 25OHD exceeded 20 ng/mL in 97.5% of whites on the 400 IU/d dose and between 800 and 1600 IU/d for African Americans. The recommended dietary allowance (RDA) suggested by the Institute of Medicine for young people is 600 IU daily. The increase in serum 25OHD after vitamin D supplementation was similar in young and old, and in white and African American women.