Vitamin D and The Magic Mountain: the anti-infectious role of the vitamin

Association of Vitamin A and D Deficiencies with Infectious Outcomes in Children Undergoing Intensive Induction Therapy for Acute Lymphoblastic Leukemia

OBJECTIVE

To evaluate the association between deficiency of vitamin A or D at diagnosis of pediatric acute lymphoblastic leukemia (ALL) and subsequent infectious complications during induction therapy.

STUDY DESIGN

We conducted an institutional review board-approved, retrospective cohort study of children with newly diagnosed ALL from 2007 to 2017 at St. Jude Children's Research Hospital. We measured vitamin D, vitamin D binding protein, retinol binding protein as a surrogate for vitamin A, and immunoglobulin isotypes in serum obtained at ALL diagnosis, and we assessed the association between vitamin deficiencies or levels and infection-related complications during the 6-week induction phase using Cox regression models.

RESULTS

Among 378 evaluable participants, vitamin A and D deficiencies were common (43% and 17%, respectively). Vitamin D deficiency was associated with higher risks of febrile neutropenia (adjusted hazard ratio [aHR], 1.7; P = .0072), clinically documented infection (aHR, 1.73; P = .025), and likely bacterial infection (aHR, 1.86; P = .008). Conversely, vitamin A deficiency was associated solely with a lower risk of sepsis (aHR, 0.19; P = .027).

CONCLUSIONS

In this retrospective study, vitamin D deficiency was associated with an increased risk of common infection-related complications during induction therapy for ALL. Additional studies are warranted to evaluate whether vitamin D supplementation could mitigate this effect.

Go Big or Go Home: Obesity and Total Joint Arthroplasty

Obesity is highly prevalent, and it is expected to grow considerably in the United States. The association between obesity and an increased risk of complications following total joint arthroplasty (TJA) is widely accepted. Many believe that patients with body mass index (BMI) >40 have complications rates that may outweigh the benefits of surgery and should consider delaying it. However, the current literature on obesity and outcomes following TJA is observational, very heterogeneous, and full of confounding variables. BMI in isolation has several flaws and recent literature suggests shifting from an exclusively BMI <40 cutoff to considering 5 to 10% preoperative weight loss. BMI cutoffs to TJA may also restrict access to care to our most vulnerable, marginalized populations. Moreover, only roughly 20% of patients instructed to lose weight for surgery are successful and the practice of demanding mandatory weight loss needs to be reconsidered until convincing evidence exists that supports risk reduction as a result of preoperative weight loss. Obese patients can benefit greatly from this life-changing procedure. When addressing the potential difficulties and by optimizing preoperative assessment and intraoperative management, the surgery can be conducted safely. A multidisciplinary patient-centered approach with patient engagement, shared decision-making, and informed consent is recommended.

Retinol Binding Protein, Sunlight Hours, and the Influenza Virus-Specific Immune Response

Healthy pediatric immune responses depend on adequate vitamin A and D levels. Relationships between solar ultraviolet B (UVB) radiation and vitamin D are well understood, while relationships between sunlight, vitamin A, and its serum escort, retinol binding protein (RBP), are not. A pediatric clinical study enrolled 2–8-year-old children at various times between September 2016 and March 2017, inclusive, in Memphis, Tennessee. A serum sample from each child was then assayed to examine the influence of season on vitamin levels. We found that RBP and RBP/retinol molar ratios decreased in winter months and RBP/retinol ratios correlated positively with the average daily sunlight hours per month. A food frequency questionnaire given to parents/guardians indicated a shift in dietary intake from plant-based foods to animal-based foods by children between winter and spring months. This translated to higher retinol and zinc (integral to RBP–transthyretin–retinol complexes) in the spring, perhaps explaining the seasonal influence on RBP/retinol. RBP and retinol were associated positively with IgG/IgM and IgA/IgM ratios. RBP and retinol, but not 25(OH)D, also correlated positively with influenza virus-specific antibodies. Retinol correlated negatively, while 25(OH)D correlated positively, with certain serum cytokine/chemokine levels. Significant differences in 25(OH)D, immunoglobulin ratios, and cytokines/chemokines were observed between black and white children. In sum, seasonal changes in dietary foods rich in retinol and zinc may have influenced RBP levels, which in turn influenced innate and adaptive immune responses. Results encourage routine monitoring and reporting of season, RBP, and vitamin levels in future clinical studies, as seasons may affect sunlight exposures, diet, vitamin levels, and immune protection against infectious disease.

Hypothesis: Low Vitamin A and D Levels Worsen Clinical Outcomes When Children with Sickle Cell Disease Encounter Parvovirus B19

Human parvovirus B19 causes life-threatening anemia due to transient red cell aplasia (TRCA) in individuals with sickle cell disease (SCD). Children with SCD experiencing profound anemia during TRCA often require red blood cell transfusions and hospitalization. The prevalence of vitamin deficiencies in SCD is high and deficiencies are associated with respiratory and pain symptoms, but the effects of vitamins on acute infection with parvovirus B19 remain unclear. We performed a clinical study in which 20 SCD patients hospitalized with parvovirus B19 infections (Day 0) were monitored over a 120-day time course to query relationships between vitamins A and D and clinical outcomes. There were significant negative correlations between Day 0 vitamin levels and disease consequences (e.g., red blood cell transfusion requirements, inflammatory cytokines). There were significant positive correlations (i) between Day 0 vitamins and peak virus-specific antibodies in nasal wash, and (ii) between Day 0 virus-specific serum plus nasal wash antibodies and absolute reticulocyte counts. There was a significant negative correlation between Day 0 virus-specific serum antibodies and virus loads. To explain the results, we propose circular and complex mechanisms. Low baseline vitamin levels may weaken virus-specific immune responses to permit virus amplification and reticulocyte loss; consequent damage may further reduce vitamin levels and virus-specific immunity. While the complex benefits of vitamins are not fully understood, we propose that maintenance of replete vitamin A and D levels in children with SCD will serve as prophylaxis against parvovirus B19-induced TRCA complications.

Vitamin D deficiency in children with acute bronchiolitis: a prospective cross-sectional case- control study

Background

25(OH) vitamin D levels are inversely associated with respiratory infections and childhood wheezing.

Objective

To evaluate serum 25(OH) vitamin D levels in infants and toddlers with acute bronchiolitis, compared to subjects with non-respiratory febrile illness.

Methods

A prospective cross-sectional case-control study which compared serum 25(OH) vitamin D levels between infants and toddlers diagnosed with acute bronchiolitis to subjects with non-respiratory febrile illness. Multivariate logistic regression, adjusted for age, sex, ethnicity and nutrition was performed. Correlation between serum vitamin D levels and bronchiolitis severity was assessed via Modified Tal Score and length of hospital stay (LOS).

Results

One hundred twenty-seven patients aged < 24 months were recruited; 80 diagnosed with acute bronchiolitis and 47 patients with non- respiratory febrile illnesses. Both groups had similar demographics aside from age (median [IQR] 5 [3–9] vs. 9 [5–16] months in the bronchiolitis group compared to control group (p = 0.002)). Serum 25(OH) vitamin D levels were significantly lower in the bronchiolitis group; median [IQR] 28[18–52] vs. 50[25–79] nmol/L, respectively, (p = 0.005). Deficient vitamin D levels (< 50 nmol/L) was found more frequently in the bronchiolitis group than controls; 73% vs. 51% (p = 0.028). Multivariate logistic regression showed vitamin D deficiency was more probable in bronchiolitis patients; OR [95% CI] 3.139[1.369–7.195]. No correlation was found between serum vitamin D levels and bronchiolitis severity, which was assessed via Modified Tal Score and by length of hospital stay.

Conclusion

Children with acute bronchiolitis displayed significantly lower vitamin D levels than children with non-respiratory acute febrile illnesses.

Month of Influenza Virus Vaccination Influences Antibody Responses in Children and Adults

The improvement of influenza virus vaccines and the development of a universal product have been long-standing goals in pre-clinical and clinical research. To meet these goals and to understand the strengths and weaknesses of current vaccine strategies, scientists routinely study human responses toward seasonal influenza vaccines. This research is frequently performed with clinical samples taken throughout an influenza season, often without strict attention to the month of inoculation for each study participant. Here, we ask how the timing of vaccination affects outcomes. Results demonstrate significant influences of inoculation month on the immune response. During the progression from fall to winter months, there are changes in host lifestyles and in the frequencies of clinical/sub-clinical viral infections that can significantly alter vaccine immunogenicity. We now recommend routine assessment of inoculation month during clinical studies to inform data interpretation and expedite the development of successful vaccines. This recommendation is pertinent to numerous vaccine development efforts within and outside the influenza virus field.

The effect of vitamin D administration on vitamin D status and respiratory morbidity in late premature infants

OBJECTIVE

To assess whether increment of vitamin D daily intake results in improved serum25(OH) vitamin D levels and reduced respiratory morbidity in premature infants.

METHODS

A randomized double-blind clinical pilot trial, including preterm infants born at 32 + 6 to 36 + 6 weeks of gestation. The control group received 400 international units (IU) of cholecalciferol daily compared to 800 IU daily in the intervention group. Levels of 25(OH) vitamin D were measured at birth and 6 and 12 months of age. Respiratory morbidity was followed until 1 year of age.

RESULTS

Fifty subjects were recruited during the study period; the median measured 25(OH) vitamin D levels in the control vs intervention groups were: 26.5 vs 34 nmol/L (P = .271) at birth, 99 vs 75.5 nmol/L (P = .008) at 6 months and 72.5 vs 75 nmol/L (P = .95) at 12 months of age. Infants with insufficient vitamin D (<75 nmol/L) levels had higher respiratory morbidity. Serum vitamin 25(OH) D is a fair predictor for respiratory symptoms (area under the curve [AUC], 0.697; 95% confidence interval [CI], 0.509-0.885; P = .047) and for recorded acute respiratory illnesses (AUC, 0.745; 95% CI, 0.569-0.922; P = .012).

CONCLUSION

Doubling the daily intake of vitamin D in premature infants did not increase serum 25(OH) vitamin D level, due to poor compliance in the intervention group. We found an inverse association between serum 25(OH) vitamin D and respiratory symptoms, indicating vitamin D deficiency is a fair predictor for respiratory morbidity.

Nuclear Receptors, Ligands and the Mammalian B Cell

Questions concerning the influences of nuclear receptors and their ligands on mammalian B cells are vast in number. Here, we briefly review the effects of nuclear receptor ligands, including estrogen and vitamins, on immunoglobulin production and protection from infectious diseases. We describe nuclear receptor interactions with the B cell genome and the potential mechanisms of gene regulation. Attention to the nuclear receptor/ligand regulation of B cell function may help optimize B cell responses, improve pathogen clearance, and prevent damaging responses toward inert- and self-antigens.

Sunlight exposure, consumption of vitamin D-rich foods and vulvovaginal candidiasis in an African population: a prevalence case-control study

BACKGROUND/OBJECTIVES

To date, only two studies have investigated the relationship between vitamin D (vitD) deficiency and candidiasis in spite of vitD's antimicrobial and immunomodulatory roles. We examined the relationship between sunlight exposure and consumption of vitD-rich foods, markers of vitD status, and vulvovaginal candidiasis (VVC) in an African population to add to the limited evidence and stimulate additional research.

SUBJECTS/METHODS

Three hundred cases (females diagnosed as suffering from VVC) and three hundred controls (females diagnosed as suffering from any condition other than VVC) were selected from three health facilities in Cape Coast, Ghana. Sunlight exposure was assessed in a structured questionnaire with a food frequency questionnaire used to ascertain the frequency of consumption of vitD-rich foods.

RESULTS

Self-reported low sunlight exposure was associated with 3.38 (95% CI:1.99, 5.74) increased odds of VVC. Low and moderate sunlight exposure estimated by outdoor visits was also associated with increased odds of VVC. In sensitivity analysis restricted to matched sunlight exposure data, low and moderate exposure was associated with 5.78 (95% CI: 2.57, 12.99) and 3.53 (95% CI: 1.85, 6.75) increased odds of VVC. Odds of VVC increased with decreasing levels of consumption of vitD-rich foods (Likelihood-ratio test trend p = 0.1382). In the joint analysis, low and moderate vitD intake was associated with much higher increased odds of VVC.

CONCLUSIONS

Our findings should be confirmed in prospective studies and clinical trials to strengthen the evidence base for preventive action and to also inform clinical decision making.

Baseline Serum Vitamin A and D Levels Determine Benefit of Oral Vitamin A&D Supplements to Humoral Immune Responses Following Pediatric Influenza Vaccination

Maximizing vaccine efficacy is critical, but previous research has failed to provide a one-size-fits-all solution. Although vitamin A and vitamin D supplementation studies have been designed to improve vaccine efficacy, experimental results have been inconclusive. Information is urgently needed to explain study discrepancies and to provide guidance for the future use of vitamin supplements at the time of vaccination. We conducted a randomized, blinded, placebo-controlled study of influenza virus vaccination and vitamin supplementation among 2 to 8 (inclusive) year old children over three seasons, including 2015–2016 (n = 9), 2016–2017 (n = 44), and 2017–2018 (n = 26). Baseline measurements of vitamins A and D were obtained from all participants. Measurements were of serum retinol, retinol-binding protein (RBP, a surrogate for retinol), and 25-hydroxyvitamin D (25(OH)D). Participants were stratified into two groups based on high and low incoming levels of RBP. Children received two doses of the seasonal influenza virus vaccine on days 0 and 28, either with an oral vitamin supplement (termed A&D; 20,000 IU retinyl palmitate and 2000 IU cholecalciferol) or a matched placebo. Hemagglutination inhibition (HAI) antibody responses were evaluated toward all four components of the influenza virus vaccines on days 0, 28, and 56. Our primary data were from season 2016–2017, as enrollment was highest in this season and all children exhibited homogeneous and negative HAI responses toward the Phuket vaccine at study entry. Responses among children who entered the study with insufficient or deficient levels of RBP and 25(OH)D benefited from the A&D supplement (p < 0.001 for the day 28 Phuket response), whereas responses among children with replete levels of RBP and 25(OH)D at baseline were unaffected or weakened (p = 0.02 for the day 28 Phuket response). High baseline RBP levels associated with high HAI titers, particularly for children in the placebo group (baseline RBP correlated positively with Phuket HAI titers on day 28, r = 0.6, p = 0.003). In contrast, high baseline 25(OH)D levels associated with weak HAI titers, particularly for children in the A&D group (baseline 25(OH)D correlated negatively with Phuket HAI titers on day 28, r = −0.5, p = 0.02). Overall, our study demonstrates that vitamin A&D supplementation can improve immune responses to vaccines when children are vitamin A and D-insufficient at baseline. Results provide guidance for the appropriate use of vitamins A and D in future clinical vaccine studies.

CYP24A1 genetic variants in the vitamin D metabolic pathway are involved in the outcomes of hepatitis C virus infection among high-risk Chinese population

BACKGROUND AND AIMS

It has been demonstrated that 1,25-hydroxyvitamin-D3-24-hydroxylase, encoded by CYP24A1 gene, is a key enzyme that neutralizes the active vitamin D3 metabolite 1,25-dihydroxyvitamin D3 [1,25(OH)₂D₃] in response to hepatitis C virus (HCV) infection. This study aimed to investigate whether CYP24A1 genetic variation is associated with HCV infection outcomes.

METHODS

848 HCV chronically infected subjects, 507 natural clearance subjects, and 1017 uninfected controls were enrolled. Nine single nucleotide polymorphisms (SNPs) in theCYP24A1 gene were genotyped using the Sequenom MassARRAY platform.

RESULTS

After adjusting for age, gender, and routes of infection, logistic regression analyses showed that rs6013897-A was associated with an elevated risk of HCV infection (P<0.05). In addition, this study has also demonstrated that rs6068816-T significantly reduced the risk of chronic HCV infection, while rs3787557-C, rs6022999-G, and rs2248359-T significantly increased the risk of chronic HCV infection (all P<0.05). Haplotype analysis suggested that, compared to the most frequent T_rs6068816T_rs3787557A_rs6022999C_rs2248359 haplotype, the CTGT haplotype (adjusted OR=1.376, 95% CI=1.092-1.735, P=0.007) and CCAC haplotype (adjusted OR=1.483, 95% CI=1.139-1.929, P=0.003) were associated with an increased risk of chronic HCV infection.

CONCLUSION

These findings indicate that SNPs in CYP24A1 gene may contribute to the risk of HCV infection and chronic HCV infection among a high-risk Chinese population.

Vitamin D's role in health and disease: How does the present inform our understanding of the past?

While the role of vitamin D in supporting bone homeostasis during growth and maintenance is well substantiated, emerging evidence from ecological and observational studies suggests that a deficiency of vitamin D is associated with some cancers, immune disorders, cardiovascular disease, abnormal glucose metabolism, and neurodegenerative diseases. Biological plausibility for extraskeletal functions originated with the discovery of the vitamin D receptor in many body tissues and knowledge that the conversion of 25-hydroxyvitamin D (25(OH)D) to its active metabolite 1,25(OH)₂D occurs in many cell types in addition to the kidney. The association of vitamin D status in humans as an etiological factor in developmental programming of bone, in some chronic diseases, and in all-cause mortality, in addition to skeletal morbidity, is supported by some but not all observational studies and randomized controlled trials. These clinical observations have implications for paleopathology, both in terms of specific comorbidities and the potential role of vitamin D in individuals who display no evidence for skeletal disease. This paper outlines recent clinical research on vitamin D metabolism and its novel biological roles, and explores the possible relevance to paleopathological research designs, theoretical models, and interpretations of disease experience.

A review of micronutrients in sepsis: the role of thiamine, l-carnitine, vitamin C, selenium and vitamin D

Sepsis is defined as the dysregulated host response to an infection resulting in life-threatening organ dysfunction. The metabolic demand from inefficiencies in anaerobic metabolism, mitochondrial and cellular dysfunction, increased cellular turnover, and free-radical damage result in the increased focus of micronutrients in sepsis as they play a pivotal role in these processes. In the present review, we will evaluate the potential role of micronutrients in sepsis, specifically, thiamine, l-carnitine, vitamin C, Se and vitamin D. Each micronutrient will be reviewed in a similar fashion, discussing its major role in normal physiology, suspected role in sepsis, use as a biomarker, discussion of the major basic science and human studies, and conclusion statement. Based on the current available data, we conclude that thiamine may be considered in all septic patients at risk for thiamine deficiency and l-carnitine and vitamin C to those in septic shock. Clinical trials are currently underway which may provide greater insight into the role of micronutrients in sepsis and validate standard utilisation.

Serum 25-Hydroxyvitamin D and Risk of Self-Reported Bacterial Vaginosis in a Prospective Cohort Study of Young African American Women

BACKGROUND

Bacterial vaginosis (BV), the leading cause of vaginal discharge, is associated with multiple adverse health outcomes; however, its etiology is unknown. BV treatment is not very effective, thus prevention approaches are needed. Studies investigating the impact of vitamin D on the risk of BV have had mixed findings, including two studies reporting increased risk of recurrent BV for women with higher vitamin D.

MATERIALS AND METHODS

Participants were nonpregnant women in a prospective fibroid study of African Americans (ages 23-34 years) from the Detroit area. The exposure was seasonally adjusted annual mean serum 25-hydroxyvitamin D [25(OH)D] at enrollment. The outcome was self-reported doctor-diagnosed BV over ∼20 months between baseline and follow-up. Multivariable-adjusted binomial regression models estimated the risk of BV for a doubling of 25(OH)D and sufficient (≥20 ng/mL) versus deficient (<20 ng/mL) 25(OH)D.

RESULTS

In total, 1459 women were included. Median 25(OH)D was 15.2 ng/mL and 73% were deficient. Sixteen percent of participants reported BV diagnoses over follow-up, 78% of whom had recurrent BV. In multivariable-adjusted analyses, a doubling of 25(OH)D was associated with an increased, rather than the hypothesized decreased, risk of self-reported BV (risk ratio [RR] 1.22, 95% confidence interval 1.02-1.48). Sufficient women also had a significantly higher, rather than lower, risk of self-reported BV (RR 1.31). Results were robust to sensitivity analyses, and post hoc analyses showed no evidence of reverse causation.

CONCLUSIONS

Overall, our findings do not support vitamin D deficiency as a risk factor for BV in these young, nonpregnant African American women.

Calcium and vitamin D in human health: Hype or real?

The incidence and prevalence of vitamin D deficiency are increasing worldwide. It is estimated that over 50% of the world's population have low vitamin D (i.e., hypovitaminosis D; serum levels below 30 ng/mL). In vitamin D inadequacy, human physiological systems work inefficiently. In humans, 80% of the vitamin D is synthesized in the presence of ultraviolet rays from sunlight; for the rest, we rely on diet and nowadays, supplements. The latter becomes important when one is exposed to less than optimal amounts of sunlight, inability to generate vitamin D in the skin efficiently, and/or having conditions that lead to decreased intestinal absorption or increased catabolism of vitamin D. The normal serum 25-hydroxyvitamin D [25(OH)D] level is around 30 ng/mL (75 nmol/L) and the optimal range is between 30 and 60 ng/mL (75-150 nmol/L). In 2011, the Institute of Medicine (IOM) suggested that 600IU of vitamin D is adequate for people below age 71 who are not exposed to sunshine. Although this might be relevant to the ambulatory healthy white Caucasians to achieve serum 25(OH)D level of 20 ng/mL, but it is insufficient for other ethnic groups. Moreover, the IOM recommendations are not suitable for those who live outside North America. Vitamin D requirements are higher during adolescence, pregnancy and lactation, and in many other disease conditions. Most clinicians consider 30 ng/mL as the minimum serum level of 25(OH)D necessary to maintain good health. In the absence of sunlight exposure and with daily oral intake of 600IU vitamin D, very few people would reach serum 25(OH)D level above 30 ng/mL. While an additional daily intake of 1000IU of vitamin D are required for people with lighter-skin color, those with darker complexion and the elderly, require a minimum of 2000IU/day to maintain serum 25(OH)D levels over 30 ng/mL; 5000 IU/day supplement is considered as the safe daily upper limit of supplementation. Vulnerable groups such as the disabled and/or house-bound, obese, with gastrointestinal abnormalities and/or malabsorption syndromes, institutionalized people (e.g., nursing homes, prisons, etc.), and pregnant and lactating women need approximately 4000IU per day for optimal physiological activity. Vitamin D is essential for gastrointestinal calcium absorption, mineralization of osteoid tissue and maintenance of serum ionized calcium level. It is also important for other physiological functions, such as muscle strength, neuromuscular coordination, hormone release, subduing autoimmunity, and curtailing the development of certain cancers.

Vitamin D deficiency in mothers, neonates and children

Vitamin D is produced in response to the exposure of skin to sunlight through UV-B synthesis. It can also be obtained from diet and dietary supplements. Vitamin D is essential for strong bones as it helps to absorb calcium from diet. Vitamin D deficiency mainly occurs if strict vegetarian diet is followed as mostly the source of vitamin D is animal based; therefore, exposure to sunlight is restricted or having dark skin color. Low vitamin D levels results in increased possibility of gestational diabetes among pregnant women, low birth weight and pre-eclampsia in infants, and mothers may suffer bone impairment, osteoporosis, hypocalcaemia, and hypertension. Vitamin D deficiency is directly linked with severe complication in mothers and neonates, causing rickets, poor fetal growth and infantile eczema in neonates. Higher prevalence rate of vitamin D deficiency has led professionals to emphasize on development of relevant precautionary measures.

Non-musculoskeletal benefits of vitamin D

The aim of this study is to determine and critically evaluate the plausible relationships of vitamin D with extra-skeletal tissues in humans. Severe vitamin D deficiency results in rickets in children and osteomalacia in adults; these beneficial effects in the musculoskeletal system and certain physiological functions are well understood. Nevertheless, mounting reports support additional beneficial effects of vitamin D, outside the musculoskeletal system. This review explores the recent advances in knowledge about the non-skeletal effects of vitamin D. Peer-reviewed papers were extracted from research databases using key words, to assess correlations between vitamin D and extra-skeletal diseases and conditions. As per the guidelines of the Preferred Reporting Items for Systematic Reviews (PRISMA); general interpretations of results are included; taking into consideration the broader evidence and implications. This review summarizes current knowledge of the effects of vitamin D status on extra-skeletal tissues with special attention given to relationships between vitamin D status and various diseases commonly affecting adults; the effects of intervention with vitamin D and exposure to sunlight. Evidence suggests that vitamin D facilitates the regulation of blood pressure; and cardiac; endothelial; and smooth muscle cell functions; playing an important role in cardiovascular protection. In addition; 1,25(OH)₂D improves immunity; subdues inflammation; and reduces the incidence and severity of common cancers; autoimmune diseases and infectious diseases. Almost all adequately powered; epidemiological and biological studies that use; adequate doses of vitamin D supplementation in D-deficient populations have reported favorable outcomes. These studies have concluded that optimizing 25(OH)D status improves the functionality of bodily systems; reduces comorbidities; improves the quality of life; and increases survival. Although accumulating evidence supports biological associations of vitamin D sufficiency with improved physical and mental functions; no definitive evidence exists from well-designed; statistically powered; randomized controlled clinical trials. Nevertheless, most studies point to significant protective effects of vitamin D in humans when the minimum 25(OH)D serum level exceeds 30ng/mL and is maintained throughout the year.

Low Retinol-Binding Protein and Vitamin D Levels Are Associated with Severe Outcomes in Children Hospitalized with Lower Respiratory Tract Infection and Respiratory Syncytial Virus or Human Metapneumovirus Detection

Retinol binding protein and vitamin D were measured in children aged <5 years hospitalized with lower respiratory tract infection and respiratory syncytial virus and/or human metapneumovirus detections. Low vitamin levels were observed in 50% of the children and were associated with significantly elevated risk of the need for intensive care unit admission and invasive mechanical ventilation.

Vitamin D and risk of preterm birth: Up-to-date meta-analysis of randomized controlled trials and observational studies

AIM

We performed a meta-analysis of randomized controlled trials (RCT) and observational studies to answer the two following questions: (i) whether low maternal circulating 25 hydroxyvitamin D (25-OHD) is associated with an increased risk of preterm birth (PTB) or spontaneous PTB (sPTB); and (ii) whether vitamin D supplementation alone during pregnancy can reduce the risk of PTB.

METHODS

Literature search was carried out using Pubmed, Web of Science and Embase databases up to June 2016. Pooled OR or relative risk (RR) with 95%CI were computed using fixed or random effects models depending on the size of heterogeneity. Subgroup analysis was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using Egger's test and Begg's test.

RESULTS

Twenty-four articles (six RCT and 18 observational studies) were identified. Maternal circulating 25-OHD deficiency (pooled OR, 1.25; 95%CI: 1.13-1.38) rather than insufficiency (pooled OR, 1.09; 95%CI: 0.89-1.35) was associated with an increased risk of PTB, and vitamin D supplementation alone during pregnancy could reduce the risk of PTB (pooled RR, 0.57; 95%CI: 0.36-0.91). This was also the case for the sPTB subgroup (circulating 25-OHD <50 vs >50 nmol/L; pooled OR, 1.45; 95%CI: 1.20-1.75).

CONCLUSIONS

Maternal circulating 25-OHD deficiency could increase PTB risk and vitamin D supplementation alone during pregnancy could reduce PTB risk. Extrapolation of the results, however, must be done with caution, and there is urgent need for larger, better-designed RCT to confirm this effect.

Maternal vitamin D insufficiency and risk of adverse pregnancy and birth outcomes: A systematic review and meta-analysis of longitudinal studies

BACKGROUND

Three previous reviews on the association of vitamin D insufficiency in pregnancy with preterm birth (PTB) and stillbirth were limited in scope and deemed inconclusive. With important new evidence accumulating, there is the need to update the previous estimates and assess evidence on other clinically important outcomes such as spontaneous abortion and Apgar score. We conducted a systematic review and meta-analysis to evaluate the quality and strength of the available evidence on the relations between vitamin D nutritional status, and pregnancy and birth outcomes.

METHODS

PubMed and Scopus databases were searched from their inception to June, 2015 with no language restrictions imposed. Eighteen longitudinal studies satisfied the inclusion criteria. Random effects model was applied in computing the summary effect estimates and their corresponding 95% confidence intervals.

RESULTS

Serum 25(OH)D levels <75 nmol/l was associated with 83% (95% CI: 1.23, 2.74) and 13% (95% CI: 0.94, 1.36) increased risk of PTB measured at <32-34 weeks and <35-37 weeks, respectively. An inverse dose-response relation was observed for both PTB outcome. Serum 25(OH)D levels <75 nmol/l was also associated with 11% increased risk of spontaneous PTB (<35-37 weeks; RR = 1.11; 95% CI: 0.75, 1.65) with a dose-response relation also noted. Vitamin D insufficiency was not associated with risk of spontaneous abortion and stillbirth (RR of 1.04 [95% CI: 0.95, 1.13] and 1.02 [95% CI: 0.96, 1.09], respectively), as well as short gestational length (ES = -0.24, 95% CI: -0.69, 0.22), and low Apgar score.

CONCLUSIONS

We found vitamin D insufficiency to be associated with risk of PTB. Regarding spontaneous abortion and stillbirth, the available evidence suggest no association with low vitamin D levels. The evidence on vitamin D nutrition and Apgar score is conflicting and controversial. Overall, the experimental evidence uncovered was small and weak. Hence, the benefits of vitamin D supplementation during pregnancy should be further evaluated through rigorous intervention studies.

"English Disease": Historical Notes on Rickets, the Bone-Lung Link and Child Neglect Issues

Nutritional or classical rickets (here labeled as "rickets") is a worldwide disease involving mostly infants and young children having inadequate sunlight exposure, often associated with a low dietary intake of Vitamin D. Rickets targets all layers of society independently of economic status with historical information spanning more than two millennia. Vitamin D is critical for the absorption of calcium and prevention of rickets in children as well as osteomalacia in adults. The initial and misleading paradigm of the 19th and 20th centuries that rickets may have been the consequence of infection has been, indeed, reversed following the identification of the Vitamin D molecule's important role in the function of the immune system. Although traditionally considered limited to osteopathology, Vitamin D deficiency is now known to be linked to infection, inflammation, and carcinogenesis. In this review, we consider the key historical (Whistler, pre-Whistler and post-Whistler descriptors) and social facts around rickets; highlight the osteo-pathological features of rickets and the pathology of the upper and lower respiratory tract, stressing the fact that lungs remain the main secondary organ affected by Vitamin D deficiency; and emphasize the public health role in identifying the cases of child neglect or abuse based on the evaluation of the costochondral region.

Patient Optimization-Strategies That Work: Malnutrition

BACKGROUND

Patient optimization is receiving increasing attention as outcomes monitoring and bundled payments have been introduced in joint arthroplasty. Optimization of nutrition is an important aspect of perioperative management.

METHODS

This manuscript is a review of previously published material related to nutrition and the impact of malnutrition on surgical outcomes, with guidance for surgeons preparing patients for elective joint arthroplasty.

RESULTS

Patients with optimized nutritional parameters have fewer complications, especially related to wound healing and infection.

CONCLUSION

Nutritional assessment and optimization should be a part of the perioperative management of patients undergoing lower extremity arthroplasty.

Role of Vitamin D in Hospitalized Children With Lower Tract Acute Respiratory Infections

BACKGROUND

Vitamin D is known to have modulatory actions in the immune system. Its influence on the severity of lower tract acute respiratory infections (LT-ARIs) is unclear.

OBJECTIVES

The aim of the present study was to evaluate the role of vitamin D on LT-ARI in paediatric patients.

METHODS

Children admitted to hospital with LT-ARI were prospectively recruited through the GENDRES network (March 2009-May 2013). The 25-hydroxyvitamin D (25-OHD) levels were measured by immunoassay. The severity of the illness was evaluated according to clinical scales, length of hospital stay, ventilatory requirements, and pediatric intensive care unit admission.

RESULTS

A total of 347 patients with a median (interquartile range) age of 8.4 (2.6-21.1) months were included. The mean (SD) 25-OHD levels in our series were 27.1 (11.3) ng/mL. In this study, a cutoff value of ≥30 ng/mL was considered optimal vitamin status. Patients with 25-OHD levels <20 ng/mL were at a higher risk of showing severe signs of respiratory difficulties (OR 5.065, 95% confidence interval 1.998-12.842; P = 0.001) than patients with normal values, and had a 117% higher risk of oxygen necessity and 217% higher risk of ventilatory requirement than those patients with normal values. An inverse correlation was found between 25-OHD levels and the severity in the evaluated scales. 25-OHD levels did not influence PICU admission rate or length of hospital stay.

CONCLUSIONS

25-OHD levels of children admitted because of a LT-ARI are <30 ng/mL. Lower levels of 25-OHD were found to be correlated with severity of the disease. The possible role of abnormal 25-OHD levels as a facilitator or consequence of the infection needs further evaluation.

The Association between Vitamin D Levels and Urinary Tract Infection in Children

AIM

We aimed to examine whether there is any association between serum levels of 25-hydroxyvitamin D [25(OH)D3] and urinary tract infection (UTI) among children.

METHODS

White blood cell count, serum C-reactive protein, calcium, phosphorus, alkaline phosphatase, parathormone, and serum 25(OH)D3 levels were measured in 82 children experiencing a first episode of UTI, with no risk factors for UTI, and 64 healthy control children.

RESULTS

The mean serum levels of 25(OH)D3 among children with UTI were significantly lower than those of controls (11.7 ± 3.3 vs. 27.6 ± 4.7 ng/ml; p < 0.001). The serum levels of 25(OH)D3 were significantly lower in patients with acute pyelonephritis compared to patients with lower UTI (8.6 ± 2.8 vs. 14.2 ± 3.0 ng/ml; p < 0.001). Within the study group, mean serum levels of 25(OH)D3 among girls were lower than those of boys (10.9 ± 3.4 ng/ml vs. 13.2 ± 4.4 ng/ml; p < 0.001). Multivariate analysis showed that a serum 25(OH)D3 level of <20 ng/ml (odds ratio 3.503, 95% confidence interval 1.621-7.571; p = 0.001) was associated with UTI in children.

CONCLUSIONS

Our results suggest that vitamin D deficiency may be a risk factor for UTI in children.

Vitamin Supplementation at the Time of Immunization with a Cold-Adapted Influenza Virus Vaccine Corrects Poor Mucosal Antibody Responses in Mice Deficient for Vitamins A and D

Vitamin A and D deficiencies and insufficiencies are prevalent worldwide in developed and developing countries. Vitamin metabolites are functionally intertwined in that they are high-affinity ligands for related receptors of the nuclear receptor superfamily. The effects of vitamin A deficiencies (VAD) on antibody responses to respiratory virus vaccines have already been demonstrated. Of particular concern was the reduction in IgA, a first line of defense against pathogens in the respiratory tract. Here, we describe the individual and combined effects of vitamin A and D deficiencies in mice immunized with an attenuated influenza virus vaccine. Relative to VAD, vitamin D deficiency (VDD) had a limited effect, but double deficiencies for vitamins A and D (VAD+VDD) further reduced antibody responses in the respiratory tract. The administration of supplemental vitamins A and D to VAD+VDD mice at the time of vaccination restored responses in a dose-dependent manner. Results suggest that vitamin supplementation programs may be beneficial in a clinical setting to promote healthy immune responses to respiratory virus vaccines in vitamin-deficient individuals.

Potential impact of maternal vitamin D status on obstetric well-being

Despite its discovery 100 years ago, vitamin D (VD) has emerged as one of the most controversial nutrients and prohormones of the 21st century. In the past few years, a growing interest in VD has been observed in the biomedical literature due to evidences demonstrating a relevant relationship not only between regulation of calcium and phosphorus homeostasis, but also multiple disease states and low VD status in the population. Indeed, several studies carried out to decipher its role in the body in almost every cell, tissue, and different organs. Recent findings suggested a significant implication of VD in different physiologic processes , such as vascular health, immune function, metabolism, and placental function. In the attempt to focus the attention on effect of VD on female reproductive health, there has been a paucity of data from randomized controlled trials to establish clear beneficial. Human and animal data suggest that low VD status is associated with impaired fertility, endometriosis, and polycystic ovary syndrome. Findings from observational studies show higher rates of preeclampsia, gestational diabetes, preterm birth, and bacterial vaginosis in women with low VD levels. By recent evidences, this review explored the association between maternal VD status and selected effects on maternal, perinatal, and infant health, and the impact of VD supplementation during pregnancy on obstetric well-being.

Retinol binding protein and vitamin D associations with serum antibody isotypes, serum influenza virus-specific neutralizing activities and airway cytokine profiles

Vitamin A supports the induction of immunoglobulin (Ig)A responses at mucosal surfaces in mice, but much less is known about the influence of vitamins on antibody isotype expression in humans. To address this knowledge gap, we examined 46 residual blood samples from adults and children, some of whom were experiencing influenza virus infections of the respiratory tract. Assays were performed for retinol binding protein (RBP, a surrogate for vitamin A), vitamin D (a related vitamin) and antibody isotypes. Results showed that all but two tested samples exhibited RBP and/or vitamin D insufficiencies or deficiencies. Vitamin D correlated with blood IgM and IgG3, while RBP correlated with IgG4 and IgA. RBP also correlated positively with age and with influenza virus-specific antibody neutralization titres. Individuals with low blood RBP levels exhibited the highest frequencies of over-expressed cytokines and growth factors in nasal wash samples, an indication of inflamed mucosal tissues. While cause-effect relationships were not discerned, results support a hypothesis that vitamins directly influence B cell isotype expression in humans, and by so doing may help protect mucosal surfaces from respiratory viral disease.

Vitamin D-dependent rickets: a resurgence of the rachitic lung in the 21st century

Respiratory complications of rickets may be life-threatening particularly in developing countries. A 7-month-old boy presented with recurrent infections, seizures, failure to thrive, wheezing and respiratory distress progressing to global respiratory failure. Several antimicrobial regimens, bronchodilators and corticosteroids resulted in only short-term improvement. He was transferred from Cape Verde to a third-care hospital in Portugal. He was hypotonic and undernourished, with respiratory anguish and classical skeletal signs of rickets, despite vitamin D supplementation. Hypocalcaemia, normal phosphate levels and normal vitamin D status 25(OH)D3 and 1.25(OH)2D3) pointed to vitamin D-dependent rickets type II. Treatment with high doses of calcium and calcitriol allowed progressive respiratory, musculoskeletal and neurological recovery. Although respiratory manifestations of rickets were described many years ago, the present case raises relevant issues about the level of diagnostic support, the risk of complications and how they should be assessed and monitored.

Knowledge, attitude, and practice of general practitioners in Dammam, Saudi Arabia towards Vitamin D supplementation to infants

Background:

With the report of high prevalence rate of Vitamin D deficiency in the literature since the 1980s, the condition can be considered an epidemic in Saudi Arabia. However, no specific steps have been taken by the Ministry of Health to tackle the problem. Moreover, little is known about general practitioners’ (GPs) knowledge, attitude, and practice (KAP) of Vitamin D supplementation for infants.

Objectives:

To measure the KAP of GPs, of Vitamin D supplementation for infants in Dammam, Saudi Arabia.

Materials and Methods:

This was a cross-sectional study of GPs practicing in primary healthcare centers in the Dammam area of Saudi Arabia. All the 110 GPs working in primary health centers (PHCs) in Dammam were invited to participate in the study. Data was collected with the help of a self-administered questionnaire. Data was analyzed using SPSS 20.0. Statistical analysis included descriptive analysis of all the variables, expressed as the mean (standard deviation [SD]) or the median if not normally distributed.

Results:

Ninety-three GPs working in the Dammam area participated in the study. Thirty percent had excellent knowledge of Vitamin D. Ninety two percent had a positive attitude toward Vitamin D supplementation and sixty percent regularly prescribed Vitamin D supplementation for infants.

Conclusion:

The majority of GPs had a positive attitude toward Vitamin D supplementation for infants. However, their knowledge and practice need improvement.

Vitamin D insufficiency and deficiency in pediatric renal transplant recipients

Vitamin D deficiency is prevalent in the pediatric CKD population. Recognizing that renal transplant recipients have CKD, we assessed the prevalence of vitamin D insufficiency and deficiency in pediatric renal transplant recipients, compared to a healthy pediatric population. We prospectively studied 25(OH)D levels in 29 pediatric renal transplant recipients and 45 control patients over one yr. The overall prevalence of vitamin D insufficiency and deficiency was common in both populations, at 76% (95% CI: 61, 87%) in the pediatric renal transplant recipients and 91% (95% CI: 80, 98%) in the control group. In the paired renal transplant samples, the mean 25(OH)D level was 52.3 ± 17.9 nmol/L in the winter and 65.6 ± 18.8 nmol/L in the summer (95% CI diff.: 3.9, 22.7), in keeping with a significant seasonal difference. The mean dietary intake of vitamin D in the renal transplant recipients, assessed by three-day dietary record, was 5.7 μg/day, with a vitamin D intake below the EAR in the majority. We did not find an association between vitamin D intake and 25(OH)D levels in this study, likely due to the low dietary intake of vitamin D within the transplant population, identifying a potential area for intervention and improvement.

Vitamin D and experimental invasive aspergillosis

Immune cells express the vitamin D receptor and vitamin D metabolizing enzymes. Favorable vitamin D effects have been indicated in tuberculosis. Vitamin D deficiency increases T helper (Th) 2 responses to Aspergillus, and it suppresses Th2 responses in cystic fibrosis-allergic bronchopulmonary aspergillosis. Can vitamin D modulate the proinflammatory effects of amphotericin B (AmB) therapy in aspergillosis? Groups of mice were infected intravenously (IV) with 3-8 × 10(6) Aspergillus fumigatus conidia. In six experiments, doses of 0.08, 2, or 4 μg/kg calcitriol (active form of vitamin D) were given intraperitoneally +/- AmB-deoxycholate (AmBd) at 0.4, 0.8, 1.2, 1.8, 3.3, or 4.5 mg/kg or 0.8 or 1.2 mg/kg IV. Calcitriol doses were selected to range from doses used in humans to those just below doses shown to decalcify murine bones. In most experiments, doses of calcitriol and AmBd (or control diluents) were given five times, on alternate days, to minimize drug-drug interactions. Calcitriol treatment began on the day of challenge, and survival assessed for 10 days. In no experiments did calcitriol alone significantly worsen or enhance survival or affect residual infection in survivors. Calcitriol also did not affect the efficacy of AmBd. In a representative experiment, AmBd at 0.8 or 1.2 mg/kg IV alone +/- calcitriol at 2 μg/kg enhanced survival (P ≤ 0.01). However, the AmBd regimens with calcitriol were not different than those without, and calcitriol alone was identical to controls. In disseminated invasive aspergillosis, calcitriol did not affect outcome nor influence antifungal efficacy.

Baseline hypovitaminosis D is not associated with poor clinical outcomes in osteoarticular infections

OBJECTIVES

Although vitamin D is recognized as an important factor in bone health, its role in osteoarticular infections is unclear. We hypothesized that low vitamin D (25-hydroxycholecalciferol) levels are associated with a lower likelihood of treatment success in osteoarticular infections.

METHODS

This was a retrospective cohort study of patients with orthopedic infections who had a 25-hydroxycholecalciferol level drawn when their infection was diagnosed. Outcomes were determined at early (3-6 months) and late (≥ 6 months) follow-up after completing intravenous antibiotics.

RESULTS

We included 223 patients seen during an 11-month period with osteoarticular infections and baseline 25-hydroxycholecalciferol levels. During the initial inpatient management of the infection, hypovitaminosis D was identified and treated. The mean 25-hydroxycholecalciferol level was 23 ± 14 ng/ml; 167 (75%) patients had levels <30 ng/ml. Overall, infection treatment success was 91% (159/174) at early follow-up and 88% (145/164) at late follow-up. 25-Hydroxycholecalciferol baseline levels were similar in those with and without successful clinical outcomes, both at early (25 ± 15 vs. 21 ± 9 ng/ml; p=0.3) and late follow-up (25 ± 15 vs. 23 ± 16 ng/ml; p=0.6).

CONCLUSIONS

To our knowledge this is the first report on hypovitaminosis D and its impact on outcomes of osteoarticular infections. Hypovitaminosis D was frequent in this cohort. With vitamin D repletion, there was no difference in treatment success whether patients had baseline hypovitaminosis or not.

Prevalence of vitamin D deficiency and insufficiency in Bulgarian patients with chronic hepatitis C viral infection

AIMS

The present pilot study aimed to determine vitamin D status in Bulgarian patients with chronic HCV infection in respect to the severity of liver disease and response to interferon-ribavirin therapy.

METHODS

The study encompassed 296 patients: 161 males (54.4%) aged 42.08 ± 14.87 years, 135 females (45.6%) aged 45.72 ± 14.34 years, 86.5% of them infected with HCV genotype 1. Total 25-hydroxyvitamin-D (25OHD) was determined by liquid chromatography/tandem-mass spectrometric detection.

RESULTS

The median 25OHD level of the studied cohort was 50.40 nmol/L (range: 29.6-71.05). 25OHD deficient (< 25 nmol/L) were 16% of patients, 33% showed profound insufficiency (25-50 nmol/L), another 33% were in the range 50-80 nmol/L (mild insufficiency), the rest 18% were 25OHD sufficient. Significantly lower 25OHD levels were registered in cases with advanced fibrosis compared to those with mild or absent fibrosis (37.10 nmol/L vs. 53.00 nmol/L, respectively, p < 0.05). This association remained unchanged by seasonal variations in 25OHD levels. Inverse relationship was found between 25OHD and HCV-RNA (p < 0.01). Patients with sustained virological response to therapy had significantly higher 25OHD levels, compared to patients who failed to achieve viral eradication (56.90 nmol/L vs. 45.00 nmol/L, p = 0.012).

CONCLUSION

More than 80% of HCV-infected patients were vitamin D-deficient and -insufficient. The inverse relationship between 25OHD levels and viral load, liver fibrosis and treatment outcomes supports the hypothesis that improvement of vitamin D status may have considerable potential to amend the host defense against HCV infection and response to therapy.

Triennial Growth Symposium--Novel roles for vitamin D in animal immunity and health

Recent years have seen significant advances in the generation, validation, and implementation of nutritional supplements for food production animals. Examination of their impact on animal performance and health requires collaboration among animal scientists, nutritionists, biochemists, immunologists, veterinarians, and others. Each provides a unique perspective on the mechanisms of action, short and long-term impacts, and most effective strategies for implementation into continuously evolving industrial practices. In this review we provide a comparative immunology perspective on the impact of vitamin D on animal performance and health, describe the differential contributions of vitamin D3 and of a commercial hydroxylated version of vitamin D3, 25-hydroxyvitamin D3 (25(OH)D3 or HyD) to swine immunity, and highlight recent advances in the technologies that can be used to dissect the cellular and molecular mechanisms that impact production animal immunity and health. Among others, we pay particular attention to how these novel approaches help decrease the variability often observed in immune-associated datasets. From a practical perspective, this is critical for evaluation of in vivo effects for this nutritional supplement as small but meaningful changes to specific immune responses are typical under normal physiological conditions. Furthermore, as the range of reagents and technologies expands for comparative animal models, it is imperative that continued efforts are placed on the capacity to compare results across different experimental platforms.

How important is vitamin D in preventing infections?

Interaction with the immune system is one of the most recently established nonclassic effects of vitamin D (VitD). For many years, this was considered to be limited to granulomatous diseases in which synthesis of active 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) or calcitriol is known to be increased. However, recent reports have supported a role for 1,25(OH)2D3 in promoting normal function of the innate and adaptive immune systems. Crucially, these effects seem to be mediated not only by the endocrine function of circulating calcitriol but also via paracrine (i.e., refers to effects to adjacent or nearby cells) and/or intracrine activity (i.e., refers to a hormone acting inside a cell) of 1,25(OH)2D3 from its precursor 25(OH)D3, the main circulating metabolite of VitD. The ability of this vitamin to influence human immune responsiveness seems to be highly dependent on the 25(OH)D3 status of individuals and may lead to aberrant response to infection or even to autoimmunity in those who are lacking VitD. The potential health significance of this has been underlined by increasing awareness of impaired status in populations across the globe. This review will examine the current understanding of how VitD status may modulate the responsiveness of the human immune system. Furthermore, we discuss how it may play a role in host resistance to common pathogens and how effective is its supplementation for treatment or prevention of infectious diseases in humans.

Prevalence of hypovitaminosis D among children with upper extremity fractures

BACKGROUND

Recent publications show a high rate of hypovitaminosis D among children in general as well as among children with fractures. 25-hydroxyvitamin D levels were analyzed from hospital records to determine the prevalence of hypovitaminosis D, with the goal of using that information in fracture management and nutritional counseling.

METHODS

We retrospectively reviewed the records of 213 children with upper extremity fractures that were treated during a 14-month period. For 181 of those patients, the 25-hydroxyvitamin D level was measured at the time of emergency department presentation or at the first clinic appointment within 2 weeks after the initial presentation. The following information was collected from the charts: fracture mechanism (high or low energy), age, sex, race, and body mass index. Vitamin D levels were categorized as normal (≥ 32 ng/mL), insufficient (20 to 32 ng/mL), or deficient (< 20 ng/mL). The levels were analyzed with respect to fracture pattern and race.

RESULTS

Of the 181 patients, 24% had deficient vitamin D levels, 41% had insufficient levels, and 35% had normal levels. There was no significant correlation with vitamin D level and mechanism of injury. African American children were more likely to have insufficient or deficient levels of vitamin D.

CONCLUSIONS

Hypovitaminosis D is common among children with upper extremity fractures. Further investigation is warranted on the use of the 25-hydroxyvitamin D level as a screening tool to predict risk of fracture and to design proper nutritional programs for children with fractures.

LEVEL OF EVIDENCE

Retrospective chart review; Level III evidence.

Vitamin D in chronic liver disease

Chronic liver disease (CLD) and several related extrahepatic manifestations such as hepatic osteodystrophy are associated with deficiency of vitamin D, which has therefore been suggested as therapeutic target. Vitamin D undergoes hepatic 25-hydroxylation, rendering the liver critical to the metabolic activation of this vitamin. Vitamin D deficiency is highly prevalent in CLD patients, and vitamin D levels are inversely related to the severity of CLD. Declining levels of carrier proteins such as albumin and vitamin D-binding protein might also be critical in CLD. Intervention studies report improvements of CLD following supplementation, and benefits to health outcomes in particular with respect to hepatitis C virus infection have recently been documented.

CONTENT

We discuss vitamin D sources, functions and metabolism with a focus on the inherent complications of analytical measurements, such as the interference of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D C-3 epimers. Global discrepancies in the definition of optimal serum 25-hydroxyvitamin D levels are covered, and the prevalence of vitamin D deficiency in CLD is reviewed. We also address the functional mechanisms underlying this deficiency, and refer to associations between genetic variation in vitamin D metabolism and CLD. Lastly, we consider the health implications of a vitamin D deficiency in CLD and consider therapeutic options.

SUMMARY

Herein, we focus on the epidemiological and functional relationships between vitamin D deficiency and CLD, followed by a discussion of the potential implications for therapeutic interventions.

Rickets: Part I

Rickets is characterized by impaired mineralization and ossification of the growth plates of growing children caused by a variety of disorders, the most frequent of which is nutritional deficiency of vitamin D. Despite ample knowledge of its etiology and the availability of cost-effective methods of preventing it, vitamin D deficiency rickets remains a significant problem in developing and developed countries. This two-part review covers the history, etiology, pathophysiology and clinical and radiographical findings of vitamin D deficiency rickets. Other less frequent causes of rickets and some of the disorders entering into the differential diagnoses of rickets are also considered. Controversial issues surrounding vitamin D deficiency include determination of what constitutes vitamin D sufficiency and the potential relationship between low levels of vitamin D metabolites in many individuals and unexplained fractures in infants.

Vitamin D status of low birth weight infants in Delhi: a comparative study

OBJECTIVE

To evaluate vitamin D status of preterm and term low birthweight (LBW) and term normal birth weight (NBW; weight ≥ 2500 g) infants at birth and in early infancy.

METHODS

We enrolled 220 LBW and 119 NBW infants along with their mothers. Blood samples of both infants and mothers were taken within 48 h of birth, and that of infants were repeated at 3 months. Serum levels of calcium, phosphate, alkaline phosphatase, 25 hydroxyvitamin D (25OHD) and parathormone (PTH) were estimated using standard tests. Our primary outcome was vitamin D deficiency (VDD; serum 25OHD <20 ng/ml in mothers and <15 ng/ml in infants). Other outcomes were raised PTH (>46 pg/ml), raised AlkP (>120 U/l in mothers and 420 U/l in infants), and clinical rickets.

FINDINGS

VDD was present in 186 (87.3%) of LBW and 103 (88.6%) of NBW infants at birth, and in 77 (60.6%) of LBW and 55 (71.6%) of NBW infants at a median corrected age of 12 and 15 weeks, respectively. VDD was almost universal (93-97%) among mothers of both groups. Raised PTH was present in 138 (63.6%) of LBW and 48 (41.4%) of NBW infants at birth, and in 58 (45.7%) of LBW and 38 (49.3%) of NBW infants at follow-up. Clinical rickets was present in 17 (13.4%) of LBW and 4 (4.9%) of NBW infants at 12-14 weeks of corrected age.

CONCLUSIONS

High prevalence of VDD in LBW as well as NBW infants with clinical rickets at an early age underlines the need to study the effect of various vitamin D supplementation regimens in these infants to identify the optimal dose.

Papel da vitamina D no lúpus eritematoso sistêmico

Além do papel na homeostase do cálcio, acredita-se que a forma ativa da vitamina D apresente efeitos imunomoduladores, suprimindo ou ativando o sistema imune. Estudos recentes têm relacionado a deficiência ou a insuficiência de vitamina D a várias doenças autoimunes, como lúpus eritematoso sistêmico, artrite reumatoide, diabetes Mellitus tipo 1 e esclerose múltipla. Dessa forma, o presente trabalho buscou descrever o metabolismo da vitamina D e suas funções, enfatizando sua ação no sistema imune bem como a participação no lúpus eritematoso sistêmico. Todas as evidências encontradas estão voltadas para a relação entre baixos níveis de vitamina D e manifestações clínicas do lúpus eritematoso sistêmico, porém ainda não está definido se a suplementação ou recuperação desses níveis possa influir na atividade da doença. Dessa forma, há necessidade de mais estudos para avaliar os possíveis benefícios terapêuticos da suplementação de vitamina D no lúpus eritematoso sistêmico.

[Vitamin D: pathophysiology and clinical applicability in paediatrics]

Vitamin D has always been associated with calcium -phosphate metabolism, but vitamin D receptors or its metabolites have been found in different body cells, indicating a possible involvement in other physiological mechanisms. Vitamin D deficiency has been associated with an increased risk of infections, autoimmune diseases, diabetes, metabolic syndrome, obesity, asthma and certain neurological diseases such as schizophrenia. Currently there are different techniques for measuring 25 (OH) cholecalciferol in blood, but the results are variable and controversial. It is important to achieve standardization of these techniques to be able to compare the results obtained in different studies. Normal physiological vitamin D levels have not yet been established, but they must be higher than 20 ng/ml (50 nmol/l) in order to perform it physiological function. It is still under discussion on how to achieve these minimum levels. Since the main source of vitamin D is sunlight, we should look for strategies that do not contradict the messages of prevention of skin cancer. In recent years, recommendations for vitamin D intake have changed, involving prophylactic activities carried out in Primary Care. This manuscript reviews the physiology, actions, laboratory determination, desirable levels, and vitamin D intake recommendations, and it highlights many questions raised by new research.

Vitamin D during pregnancy and maternal, neonatal and infant health outcomes: a systematic review and meta-analysis

Vitamin D has well-defined classical functions related to calcium metabolism and bone health but also has non-classical effects that may influence other aspects of health. There has been considerable recent interest in the role of vitamin D on outcomes related to pregnancy and young child health but few efforts have been made to systematically consolidate this evidence to inform the research and policy agenda for low-income countries. A systematic review was undertaken to identify intervention and observational studies of vitamin D supplementation, intake or status (25-hydroxy-vitamin D) during pregnancy on perinatal and infant health outcomes. Data from trials and observational studies isolating the effect of vitamin D supplementation and intake were extracted and study quality was evaluated. Meta-analysis was used to pool effect estimates. We identified five randomised trials with outcomes of relevance to our review. All had small sample size and dosage amount, duration and frequency varied as did the ability to correct deficiency. Pooled analysis of trials using fixed-effects models suggested protective effects of supplementation on low birthweight (three trials, risk ratio (RR) = 0.40 [95% confidence interval (CI) 0.23, 0.71]) and non-significant but suggestive effects of daily supplementation on small-for-gestational age (two trials, RR = 0.67 [0.40, 1.11]). No effect on preterm delivery (<37 weeks) was evident (two trials, RR = 0.77 [0.35, 1.66]). Little evidence from trials exists to evaluate the effect of vitamin D supplementation during pregnancy on maternal, perinatal or infant health outcomes. Based on both trials and observational studies, we recommend that future research explore small-for-gestational age, preterm delivery, pre-eclampsia, and maternal and childhood infections, as outcomes of interest. Trials should focus on populations with a high prevalence of vitamin D deficiency, explore the relevance of timing of supplementation, and the dosage used in such trials should be sufficient to correct deficiency.