Vitamin D status of women in the Geelong Osteoporosis Study: association with diet and casual exposure to sunlight

The necessity of gestational vitamin D supplementation depends on ambient temperature: concern for infant vitamin D status

Background

Given the ease of access to ambient temperature, it may be a more practical guide than the UVB index. However, the association between gestational temperature and vitamin D level in newborns remains unclear. Our study aims to explore this association and the necessity of maternal vitamin D supplementation when ambient temperature is less than a specific value.

Methods

Based on a birth cohort study, we measured cord blood concentrations of 25(OH)D in 1419 neonates from January to September 2008 in Hefei, a new first-tier city in China. The daily mean temperature of Hefei was obtained from the China Meteorological Data Sharing Service System. Individual information on sociodemographic characteristics, perinatal health status, lifestyle, and birth outcomes was collected prospectively.

Results

The best-fit relationship was observed in the regression model using a quadratic function to describe the association between the ambient temperature of the eighth gestational month (29-32 gestational weeks) and cord blood 25(OH)D concentrations (R 2 = 0.358, p < 0.001). Ambient temperatures of 10 and 24.5°C were linked to the cutoff of vitamin D inadequacy (<50 nmol/L) and deficiency (<30 nmol/L) in cord blood, respectively. For maternal exposure to an ambient temperature of ≥24.5°C in the eighth gestational month, vitamin D supplementation during pregnancy failed to significantly enhance neonatal vitamin D concentrations. In contrast, for maternal exposure to ambient temperature of <10°C, maternal vitamin D supplementation was significantly associated with elevated 25(OH)D concentrations in cord blood.

Conclusion

Gestational ambient temperature may be an ideal predictor for infant vitamin D status screening. Maternal exposure to an ambient temperature of less than 10°C is a critical index in the eighth gestational month, which may determine the onset of vitamin D supplementation.

Vitamin D as a Modulator of Neuroinflammation: Implications for Brain Health

Neuroinflammation represents a critical immune response within the brain, playing a pivotal role in defense against injury and infection. However, when this response becomes chronic, it can contribute to the development of various neurodegenerative and psychiatric disorders. This bibliographic review delves into the role of vitamin D in modulating neuroinflammation and its implications for brain health, particularly in the context of neurological and psychiatric disorders. While vitamin D is traditionally associated with calcium homeostasis and bone health, it also exerts immunomodulatory and neuroprotective effects within the central nervous system. Through comprehensive analysis of preclinical and clinical studies, we uncover how vitamin D, acting through its receptors in glial cells, may influence the production of proinflammatory cytokines and antioxidants, potentially mitigating the cascade of events leading to neuronal damage. Clinical research has identified vitamin D deficiency as a common thread in the increased risks of multiple sclerosis, Parkinson's disease, Alzheimer's, and depression, among others. Furthermore, preclinical models suggest vitamin D's regulatory capacity over inflammatory mediators, its protective role against neuronal apoptosis, and its contribution to neurogenesis and synaptic plasticity. These insights underscore the potential of vitamin D supplementation not only in slowing the progression of neurodegenerative diseases but also in improving the quality of life for patients suffering from psychiatric conditions. Future clinical studies are essential to validate these findings and further our understanding of vitamin D's capacity to prevent or alleviate symptoms, opening new avenues for therapeutic strategies against neuroinflammation-related pathologies. Neuroinflammation is a crucial immune response in the brain against injuries or infections, but its persistence can lead to diseases such as Alzheimer's, Parkinson's, multiple sclerosis, and depression. Cholecalciferol (Vitamin D3) emerges as a regulator of neuroinflammation, present in brain cells such as astrocytes and microglia, modulating immune function. Vitamin D's mechanisms of action include cytokine modulation and regulation of nuclear and mitochondrial genes. It adjusts inflammatory mediators and antioxidants, resulting in neuroprotective effects. Additionally, vitamin D impacts neurotransmitter synthesis and brain plasticity. This positions vitamin D as a potential adjunct in treating diseases like Alzheimer's and Parkinson's. Lastly, its role in intestinal microbiota and serotonin synthesis contributes to psychiatric disorders like schizophrenia and depression. Thus, vitamin D presents a novel therapeutic approach for neuroinflammatory, neurodegenerative, and neuropsychiatric diseases.

Vitamin D supplementation during pregnancy to prevent vitamin D deficiency in newborns: a systematic review and meta-analysis

Abstract Objectives: to assess the effects of vitamin D supplementation during pregnancy on the outcomes of vitamin D concentration in newborns, length at birth, overall health (Apgar), birth weight and maternal vitamin D concentration after childbirth. Methods: this research was conducted in the electronic databases of MEDLINE, LILACS, EMBASE and Cochrane Library until December 2020, using the terms “vitamin D”, “pregnancy”, “vitamin D deficiency”, “infant”, “newborn” and their synonyms. Randomized controlled trials were searched by evaluating the effects of maternal vitamin D supplementation in neonates. The data was analyzed on RevMan 5.4 software and the quality of evidence on GRADE. Results: the newborn’s overall health condition was presented as Apgar, with a mean difference (MD) of 0.15 (CI95%=0.06-0.25; p=0.002; I2=0%, two studies, 648 participants, moderate quality evidence) at the first minute and 0.11 (CI95%=0.04-0.17; p=0.001; I2=0%, two studies, 648 participants, moderate quality evidence) at the fifth minute. Significant effects were also presented at the length at birth considering any supplemented dose (MD=0.19; CI95%=0.08-0.30; p=0.0010; I2=0%, 1452 participants, low quality evidence) and birth weight in doses higher than 4000IU/day (MD=257.05 (CI95%=137.81-376.29; p<0.0001; I2=14%, 176 participants, moderate quality evidence). Conclusion: vitamin D supplementation during pregnancy improves serum 25 (OH) D concentration and suggests positive effects on overall health condition, length at birth and birth weight. PROSPERO CRD42017073292.

The Vitamin D in Pregnancy Study: a prospective prebirth cohort in southern Australia

PURPOSE

The Vitamin D in Pregnancy Study is a long-term ongoing cohort study. It was conceived to explore relationships between maternal vitamin D status in pregnancy and offspring growth and development, and has since diversified to include a wide range of physical and mental health exposures and outcomes.

PARTICIPANTS

Recruitment was from the University Hospital Geelong (Barwon Health) antenatal clinic, Geelong, Victoria, Australia, between 2002 and 2004. 475 women were initially recruited, which resulted in 400 eligible mother-child pairs at birth.

FINDINGS TO DATE

The cohort has been followed up twice in pregnancy, at birth, and 1 year, 6 years and 11 years post birth. The study has reported an association between vitamin D in pregnancy and musculoskeletal health and body composition in the children.

FUTURE PLANS

Subject to funding, there will be a prospective young adult follow-up. This profile aims to foster both cross-national and international collaborations with both existing and future data collection.

Simulated manned Mars exploration: effects of dietary and diurnal cycle variations on the gut microbiome of crew members in a controlled ecological life support system

BACKGROUND

Changes in gut microbiome are closely related to dietary and environment variations, and diurnal circle interventions impact on human metabolism and the microbiome. Changes in human gut microbiome and serum biochemical parameters during long-term isolation in a controlled ecological life support system (CELSS) are of great significance for maintaining the health of crewmembers. The Green Star 180 project performed an integrated study involving a four-person, 180-day duration assessment in a CELSS, during which variations in gut microbiome and the concentration of serum 25-hydroxyvitamin D, α-tocopherol, retinol and folic acid from the crewmembers were determined.

RESULTS

Energy intake and body mass index decreased during the experiment. A trade-off between Firmicutes and Bacteroidetes during the study period was observed. Dynamic variations in the two dominant genus Bacteroides and Prevotella indicated a variation of enterotypes. Both the evenness and richness of the fecal microbiome decreased during the isolation in the CELSS. Transition of diurnal circle from Earth to Mars increased the abundance of Fusobacteria phylum and decreased alpha diversity of the fecal microbiome. The levels of serum 25-hydroxyvitamin D in the CELSS were significantly lower than those outside the CELSS.

CONCLUSIONS

The unique isolation process in the CELSS led to a loss of alpha diversity and a transition of enterotypes between Bacteroides and Prevotella. Attention should therefore be paid to the transition of the diurnal circle and its effects on the gut microbiome during manned Mars explorations. In particular, serum 25-hydroxyvitamin D levels require monitoring under artificial light environments and during long-term space flight. Large-scale studies are required to further consolidate our findings.

Maternal vitamin D in pregnancy and offspring bone measures in childhood: The Vitamin D in Pregnancy study

Previously we have demonstrated an association between maternal serum 25-hydroxyvitamin D (25(OH)D) during pregnancy and knee-heel length in offspring at birth. However, it is unknown whether maternal serum 25(OH)D is associated with bone measures in childhood. Thus, we aimed to examine associations between 25(OH)D at two stages of pregnancy and offspring bone measures at 11 years. Women were recruited from a single antenatal clinic in Victoria, Australia before 16 weeks gestation and provided two serum samples to determine 25(OH)D status at recruitment and 28-32 weeks gestation. Children and their mothers were followed up at 11 years of age. Children undertook dual energy X-ray absorptiometry scans at the lumbar spine and total body. Maternal 25(OH)D at recruitment (before 16 weeks gestation) was positively associated with the children's bone mineral content and density in boys, but not girls. In boys, a 10 nmol/L (4 ng/mL) increase in maternal 25(OH)D was associated with a median 0.5 g (95% CI 0.1,0.8) and 0.009 g/cm² (95% CI 0.001,0.017) increase in bone mineral content and density at the spine, respectively, and a median 0.006 g/cm² (95% CI 0.001,0.011) increase in at the total body. There was no sustained associations with 25(OH)D at the later timepoint (28-32 weeks) with any outcome. At age 11 years, maternal 25(OH)D levels during early pregnancy, but not late were positively associated with bone measures in boys, but not girls.

Assessment of vitamin D status in Czech children

OBJECTIVE

Vitamin D deficiency is a global health problem. The aim of this study was to determine the proportion of Czech children with vitamin D deficiency and examine related factors.

METHODS

The study subjects were 419 healthy children aged 5 and 9 years. Severe vitamin D deficiency was defined as a serum 25(OH)D level of < 25 nmol/L (3% of children), deficiency as that of 25-50 nmol/L (24% of children), insufficiency as that of 50-75 nmol/L (40% of children) and sufficiency as that of > 75 nmol/L (34% of children).

RESULTS

Serum 25(OH)D levels varied mainly with season. The highest levels of 25(OH)D were reached in autumn (median: 79.0 nmol/L), followed by summer (median: 67.8 nmol/L) and winter (median: 56.0 nmol/L). The lowest median value (49.8 nmol/L) was detected in spring.

CONCLUSION

Children with sufficiency 25(OH)D levels were more frequently exposed to the sun and exposed a larger part of their body to the sun while spending time outdoors. Levels of 25(OH)D were also associated with using vitamin D supplements within six weeks before sampling.

Pretiree lifestyles in relation to musculoskeletal health: cross-sectional data from the Geelong Osteoporosis Study

Background: What happens in the early-elderly ‘pretiree’ period potentially influences the divergent paths of healthy or unhealthy ageing. In this cross-sectional study, we aimed to profile musculoskeletal health and lifestyle behaviours for men and women in their late-fifties and sixties.Methods: For 482 participants from the Geelong Osteoporosis Study, we measured DXA-derived appendicular lean mass (rALM), bone mineral density (BMD) at the femoral neck and percentage body fat mass (%BF). Low-rALM and low-BMD referred to sex-specific T-scores<-1.0. Associations between exposures and low-rALM and/or low-BMD were explored using multivariable logistic regression.Results: Three-quarters of participants had high %BF, 98(20.3%) had low-rALM, 202(41.9%) had low-BMD and 63(13.1%) had both low-rALM and low-BMD. Eight-two (17.0%) were very active and one-third participated in sports/recreational activities. Most [n=416(87.8%)] met the recommended daily intake (RDI) for protein; only 119(25.1%) met the RDI for calcium. Less than 10% smoked and one-third exceeded recommended alcohol intakes. Independent of age, weight and sex, greater %BF and sedentary behaviour increased the likelihood of low-rALM; high-alcohol consumption increased the likelihood of low-BMD; and greater %BF increased the likelihood of low-rALM and low-BMD combined.Conclusions: One-half of participants had rALM and BMD in the normal range. Only a few were involved in resistance-training or weight-bearing exercise, despite having the capacity to be physically active. As sedentary lifestyles, excessive adiposity and high alcohol use were associated with low-rALM and/or low-BMD, we propose that these adverse factors be potential targets among pretirees to minimise their risk of entering old age with poor musculoskeletal health. 

Assessment of research waste part 2: wrong study populations- an exemplar of baseline vitamin D status of participants in trials of vitamin D supplementation

BACKGROUND

Research waste can occur when trials are conducted in the wrong populations. Vitamin D deficient populations are most likely to benefit from vitamin D supplementation. We investigated waste attributable to randomised controlled trials (RCTs) of supplementation in populations that were not vitamin D deficient.

METHODS

In December 2015, we searched Pubmed, recent systematic reviews, and three trial registries for RCTs of vitamin D with clinical endpoints in adults, and 25-hydroxvitamin D (25OHD) survey data relevant to large (N ≥ 1000) RCTs. We investigated the proportion of RCTs that studied vitamin D deficient populations, temporal trends in baseline 25OHD, and whether investigators in large RCTs considered relevant 25OHD survey data or systematic reviews in their trial justifications.

RESULTS

Of 137 RCTs of vitamin D with clinical endpoints, 118 (86%) reported baseline mean/median 25OHD, which was < 25, 25-49, 50-74, and ≥ 75 nmol/L in 12 (10%), 62 (53%), 36 (31%), and 8 (7%) RCTs, respectively. In 70% of RCTs, baseline 25OHD was > 40 nmol/L. Baseline 25OHD increased over time. Before 2006, 38%, 62%, 0% and 0% of RCTs had baseline 25OHD < 25, 25-49, 50-74, and ≥ 75 nmol/L respectively; in 2011-15, the respective proportions were 9%, 49%, 37%, and 6%. Of 12 RCTs with baseline 25OHD < 25 nmol/L, 8 had neutral findings. Of 25 large RCTs (18 completed, 7 ongoing), 1 was undertaken in a vitamin D deficient population, 3 in vitamin D insufficient populations, and 17 had, or probably will have, baseline 25OHD > 40 nmol/L. 44% (8/18) of large completed RCTs cited relevant prior population 25OHD data, and only 3/10 (30%) relevant prior systematic reviews.

CONCLUSIONS

Up to 70% of RCTs of vitamin D with clinical endpoints, 71% of large completed RCTs, and 100% of ongoing large RCTs could be considered research waste because they studied cohorts that were not vitamin D deficient.

Vitamin D during pregnancy and offspring body composition: a prospective cohort study

BACKGROUND

Evidence regarding the association between gestational vitamin D status and offspring body composition during childhood is inconsistent. Therefore, we aimed to determine the association between maternal vitamin D and offspring lean and fat mass in the Vitamin D in Pregnancy birth cohort.

METHODS

Subjects were mother-child pairs recruited from the Australian-based Vitamin D in Pregnancy cohort study. Mothers were recruited before 16 weeks' gestation and provided a blood sample at both recruitment and at 28-32 weeks' gestation. Serum vitamin D [25(OH)D] was measured by radioimmunoassay (Tyne and Wear, UK). Offspring lean and fat mass were quantified by using dual-energy X-ray absorptiometry (GE Lunar Prodigy, Madison, WI, USA) at 11 years of age.

RESULTS

Median maternal 25(OH)D levels were 55.9 (42.2-73.3) and 56.1 (43.6-73.9) at recruitment and 28-32 weeks' gestation, respectively. Maternal smoking was identified as an effect modifier in the association between maternal vitamin D status at recruitment and offspring body composition. In smokers, but not non-smokers, serum 25(OH)D status at recruitment was negatively associated with offspring fat mass percentage and positively associated with lean mass (both p < 0.05). There was no association with 25(OH)D status at 28-32 weeks' gestation.

CONCLUSIONS

Maternal vitamin D status in early pregnancy, in smokers, is associated with offspring body composition. These important findings warrant confirmation in larger studies and trials.

Maternal Nutrition During Pregnancy: Intake of Nutrients Important for Bone Health

Objectives Maternal nutrition during pregnancy plays an important role in predisposing offspring to the development of chronic disease in adulthood, including osteoporosis. Our aim was to investigate maternal dietary intakes during pregnancy, with a focus on nutrients important for skeletal development in the offspring. Methods In this case-control study, cases were pregnant women recruited for the Vitamin D in Pregnancy Study (n = 350, age 20-40 years) and controls were non-pregnant peers participating in the Geelong Osteoporosis Study (n = 305, age 20-40 years). Dietary intakes of nutrients were quantified using a validated food frequency questionnaire. Results Compared to controls, cases consumed more energy [median (interquartile range): 7831 (6506-9461) vs. 7136 (6112-8785) kJ/day]; median intakes for cases were greater for carbohydrates [206.2 (172.5-249.9) vs. 188.2 (147.7-217.5) g/day], fat [77.9 (60.3-96.6) vs. 72.1 (53.3-87.4) g/day], potassium [2860 (2363-3442) vs. 2606 (2166-3442) mg/day] and calcium [1022 (819-1264) vs. 918 (782-1264) mg/day] (all p ≤ 0.05). However, pregnant women were not consuming greater amounts of those nutrients which had an increased demand (protein, magnesium, phosphorus and zinc). Similarly, this translated to the likelihood of achieving national recommendations for corresponding nutrients. Conclusions for Practice Compared to their non-pregnant peers, pregnant women were more likely to meet dietary recommendations for calcium and potassium; however, this was not the pattern observed for protein, magnesium and zinc. Future public health messages should perhaps focus on increasing awareness of the importance of all these nutrients during pregnancy.

Food sources of vitamin D and their association with 25-hydroxyvitamin D status in Dutch older adults

Various populations are at increased risk of developing a low vitamin D status, in particular older adults. Whereas sun exposure is considered the main source of vitamin D, especially during summer, dietary contributions should not be underestimated. This study aims to identify food sources of vitamin D that associate most strongly with serum vitamin D concentration. Data of 595 Dutch adults, aged ≥65 years, were analysed. Vitamin D intake was assessed with a food frequency questionnaire and 25-hydroxyvitamin D (25(OH)D) was determined in serum. Associations of total vitamin D intake and vitamin D intake from specific food groups with serum 25(OH)D status were examined by P-for trend analyses over tertiles of vitamin D intake, prevalence ratios (PRs), and spline regression. The prevalence of vitamin D deficiency was high, with 36% of the participants having a 25(OH)D status <50nmol/L. Participants with adequate 25(OH)D concentrations were more likely to be men and more likely to be younger than participants with vitamin D deficiency. Total median vitamin D intake was 4.3μg/day, of which 4.0μg/day was provided by foods. Butter and margarine were the leading contributors to total vitamin D intake with 1.8μg/day, followed by the intake of fish and shellfish with 0.56μg/day. Participants with higher intakes of butter and margarine were 21% more likely to have a sufficient 25(OH)D status after adjustment for covariates (T1 vs. T3: PR 1.0 vs. 1.21 (95%CI: 1.03-1.42), P-for trend 0.02). None of the other food groups showed a significant association with the probability of having a sufficient 25(OH)D status. This study shows that vitamin D intake was positively associated with total serum 25(OH)D concentration, with butter and margarine being the most important contributors to total vitamin D intake.

Predictors and correlates of serum 25-hydroxyvitamin D concentrations in young women: results from the Safe-D study

Vitamin D deficiency is a global public health concern. Studies of serum 25-hydroxyvitamin D (25(OH)D) determinants in young women are limited and few include objective covariates. Our aims were to define the prevalence of vitamin D deficiency and examine serum 25(OH)D correlates in an exploratory study of women aged 16–25 years. We studied 348 healthy females living in Victoria, Australia, recruited through Facebook. Data collected included serum 25(OH)D assayed by liquid chromatography-tandem MS, relevant serum biochemistry, soft tissue composition by dual-energy X-ray absorptiometry, skin melanin density, Fitzpatrick skin type, sun exposure using UV dosimeters and lifestyle factors. Mean serum 25(OH)D was 68 (sd27) nmol/l and 26 % were vitamin D deficient (25(OH)D <50 nmol/l). The final model explained 56 % of 25(OH)D variance. Serum sex hormone-binding globulin levels, creatinine levels, sun exposure measured by UV dosimeters, a positive attitude towards sun tanning, typically spending >2 h in the sun in summer daily, holidaying in the most recent summer period, serum Fe levels, height and multivitamin use were positively associated with 25(OH)D. Fat mass and a blood draw in any season except summer was inversely associated with 25(OH)D. Vitamin D deficiency is common in young women. Factors such as hormonal contraception, sun exposure and sun-related attitudes, as well as dietary supplement use are essential to consider when assessing vitamin D status. Further investigation into methods to safely optimise vitamin D status and to improve understanding of the impact of vitamin D status on long-term health outcomes is required.

Factors Influencing Serum-Hydroxivitamin D Levels and Other Bone Metabolism Parameters in Healthy Older Women

OBJECTIVE

Older women have frequently low serum 25-hydroxivitamin D (25[OH]D) concentrations, high parathormone (PTH) levels and low bone mineral density (BMD) values. Endogenous synthesis, dietary habits, sunlight exposure and fat-mass-mediated storage may influence 25(OH)D levels and bone metabolism, but the relevance of these factors in the elderly has yet to be fully elucidated. We aimed to investigate the influence of dietary vitamin D intake and fat mass on serum 25(OH)D levels and bone metabolism in older women.

DESIGN

Cross-sectional.

SETTING

Community.

PARTICIPANTS

218 fit older women attending a biweekly mild fitness program.

MEASUREMENTS

Dietary habits was investigated through a 3-day record questionnaire. Serum 25(OH)D and intact parathormone (PTH) concentrations were measured by radioimmunoassay and by a 2-step immunoradiometric assay, respectively. BMD and body composition were estimated using dual-energy X-ray absorptiometry with fan-beam technology.

RESULTS

Only fat mass showed a significant negative association with 25(OH)D (β=-3.76, p<0.001), and positive associations with whole body, lumbar, femoral neck and total hip BMD. Binary logistic analysis revealed a protective effect of adiposity on secondary hyperparathyroidism (OR=0.42, 95%CI:0.19-0.92, p=0.03). Dietary vitamin D intake was not associated to any of these outcomes.

CONCLUSION

Fat mass has a greater influence on serum 25(OH)D than dietary vitamin D intake.

Relative importance of summer sun exposure, vitamin D intake, and genes to vitamin D status in Dutch older adults: The B-PROOF study

BACKGROUND/OBJECTIVES

The prevalence of vitamin D deficiency among seniors is high. Whereas sun exposure, vitamin D intake, genes, demographics, and lifestyle have been identified as being important determinants of vitamin D status, the impact of these factors is expected to differ across populations. To improve current prevention and treatment strategies, this study aimed to explore the main determinants of vitamin D status and its relative importance in a population of community-dwelling Dutch older adults.

METHODS/SUBJECTS

Serum 25-hydroxyvitamin D (25(OH)D) was measured in 2857 adults aged ≥65 years. Sun exposure was assessed with a structured questionnaire (n=1012), vitamin D intake using a Food Frequency Questionnaire (n=596), and data on genetic variation that may affect 25(OH)D status was obtained for 4 genes, DHCR7 (rs12785878), CYP2R1 (rs10741657), GC (rs2282679), and CYP24A1 (rs6013897) (n=2530).

RESULTS

Serum 25(OH)D concentrations <50nmol/L were observed in 45% of the population; only 6% of these participants used vitamin D supplements. Sun exposure (being outside daily during summer: 66±25nmol/L vs not being outside daily during summer: 58±27nmol/L, P=0.02) and vitamin D intake (per unit μg/day during winter/spring: 3.1±0.75nmol/L, P<0.0001) were associated with higher 25(OH)D concentrations. Major allele carriers of SNPs related to DHCR7, CYP24A1, and GC, as well as CYP2R1 minor allele carriers had the highest 25(OH)D concentrations. Together, sun (R²=0.29), vitamin D intake (R²=0.24), and genes (R²=0.28) explained 35% (R²=0.35) of the variation in 25(OH)D concentrations during summer/autumn period, when adjusted for age, sex, BMI, education, alcohol consumption, smoking, physical activity, and self-rated health status (n=185).

CONCLUSION

The investigated determinants explained 35% of 25(OH)D status. Of the three main determinants under study, sun exposure still appeared to be an important determinant of serum 25(OH)D in older individuals, closely followed by genes, and vitamin D intake. Given the low frequency of vitamin D supplement use in this population, promoting supplement use may be an inexpensive, easy, and effective strategy to fight vitamin D deficiency.

Maternal vitamin D supplementation during pregnancy prevents vitamin D deficiency in the newborn: an open-label randomized controlled trial

OBJECTIVE

To determine whether maternal vitamin D supplementation, in the vitamin D deficient mother, prevents neonatal vitamin D deficiency.

DESIGN

Open-label randomized controlled trial.

SETTING

Metropolitan Melbourne, Australia, tertiary hospital routine antenatal outpatient clinic.

PARTICIPANTS

Seventy-eight women with singleton pregnancies with vitamin D deficiency/insufficiency (serum 25-OH Vit D < 75 nmol/l) at their first antenatal appointment at 12-16-week gestation were recruited.

INTERVENTION

Participants were randomized to vitamin D supplementation (2000-4000 IU cholecalciferol) orally daily until delivery or no supplementation.

MAIN OUTCOME MEASURES

The primary outcome was neonatal serum 25-OH vit D concentration at delivery. The secondary outcome was maternal serum 25-OH vit D concentration at delivery.

RESULTS

Baseline mean maternal serum 25-OH vit D concentrations were similar (P = 0·9) between treatment (32 nmol/l, 95% confidence interval 26-39 nmol/l) and control groups (33 nmol/l, 95% CI 26-39 nmol/l). Umbilical cord serum 25-OH vit D concentrations at delivery were higher (P < 0·0001) in neonates of treatment group mothers (81 nmol/l, 95% CI; 70-91 nmol/l) compared with neonates of control group mothers (42 nmol/l, 95% CI; 34-50 nmol/l) with a strongly positive correlation between maternal serum 25-OH Vit D and umbilical cord serum 25-OH vit D concentrations at delivery (Spearman rank correlation coefficient 0·88; P < 0·0001). Mean maternal serum 25-OH Vit D concentrations at delivery were higher (P < 0·0001) in the treatment group (71 nmol/l, 95% CI; 62-81 nmol/l) compared with the control group (36 nmol/l, 95% CI; 29-42 nmol/l).

CONCLUSION

Vitamin D supplementation of vitamin D deficient pregnant women prevents neonatal vitamin D deficiency.

An internet based approach to improve general practitioners' knowledge and practices: the development and pilot testing of the "ABC's of vitamin D" program

BACKGROUND

Online continuing medical education (CME) offers a number of advantages for physicians including flexibility with regards to location and timing of use. In order to effect physician practices and improve patient outcomes, it is important that the development of online CME is theory and evidence-based.

OBJECTIVES

This paper aims to describe the development of an online CME program for practising general practitioners (GPs) on vitamin D and sun health called "The ABC's of Vitamin D for GPs" using elements of design principles for physician-education web sites as a framework. The paper will also report the program's usability and acceptability pilot test results.

METHODS

The ABC's of Vitamin D program was developed following nine principles: needs assessment; evidence-based content development; multimodal program and modularisation; clinical cases; tailoring and interactivity; audit and feedback; credibility of the web site host; patient education materials; ease of use and navigation. Among the 20 GPs invited, acceptability and useability was tested with 12 GPs (60%) who agreed to participate and were interviewed following use of the program. The study was conducted between 2011 and 2013.

RESULTS

An online CME program consisting of eight modules was constructed. Of the 12 participating GPs, most (n=11) reported that the program was clear and easy to understand, logical, easy to navigate, and took a reasonable amount of time (estimated between 1 and 3h) to complete. Eleven of 12 participants said they would use the program as an accredited CME activity and all participants indicated that the program was 'very or somewhat' likely to lead to changes in the advice patients are given.

CONCLUSION

This study found that a theory and evidence based approach for the development of an online CME program for GPs was acceptable to users. Further research is needed to examine whether the online CME program is effective at changing GP practices and improving patient outcomes.

Validation of a Sun Exposure Questionnaire Among Subjects with Type 2 Diabetes Residing in South Florida

To validate a sun exposure questionnaire against objective measures of change in skin color and to assess its validity in predicting 25(OH)D in a sample of African Americans and Hispanics with type 2 diabetes. Ninety subjects were enrolled. The sun exposure score was calculated by multiplying the time spent outdoors times the skin exposed score. Skin color was determined by reflectance colorimetry. The relationship between serum 25(OH)D, skin exposure score and stomach skin color was evaluated by a multi-linear regression model. The unadjusted model showed that skin exposure score (P = 0.037), and stomach skin color (P = 0.021) were associated with serum 25(OH)D. This relationship remained significant only for stomach skin color (P = 0.020) after controlling for covariates. It may be possible that the color of the skin is a better predictor of 25(OH)D in this particular population than sun exposure behaviors.

Vitamin D levels in an Australian population

BACKGROUND

Levels of vitamin D in the population have come under increasing scrutiny, however there are only a few studies in Australia which measure levels in the general population. The aim of this study was to measure the levels of vitamin D within a large population cohort and examine the association with seasons and selected demographic and health risk factors.

METHODS

A longitudinal cohort study of 2413 participants in the northwest suburbs of Adelaide, South Australia conducted between 2008 and 2010 was used to examine serum levels of 25-hydroxy vitamin D (25(OH)D) in relation to demographic characteristics (age, sex, income, education and country of birth), seasons, the use of vitamin D supplements and selected health risk factors (physical activity, body mass index and smoking). Both unadjusted and adjusted mean levels of serum 25(OH)D were examined, as were the factors associated with the unadjusted and adjusted prevalence of serum 25(OH)D levels below 50 and 75 nmol/L.

RESULTS

Overall, the mean level of serum 25(OH)D was 69.2 nmol/L with 22.7% of the population having a serum 25(OH)D level below 50 nmol/L, the level which is generally recognised as vitamin D deficiency. There were significantly higher levels of 25(OH)D among males compared to females (t = 4.65, p < 0.001). Higher levels of 25(OH)D were also measured in summer and autumn compared with winter and spring. Generally, mean levels of 25(OH)D were lower in those classified as obese. Smokers and those undertaking no or less than 150 minutes/week of physical activity also had lower levels of serum vitamin D. Obesity (as classified by body mass index), season and undertaking an insufficient level of physical activity to obtain a health benefit were significantly associated with the prevalence of vitamin D deficiency.

CONCLUSIONS

Vitamin D deficiency is prevalent in South Australia, affecting almost one quarter of the population and levels are related to activity, obesity and season even when adjusted for confounding factors. Improved methods of addressing vitamin D levels in population are required.

Symptoms, health behavior and understanding of menopause therapy in women with premature menopause

OBJECTIVE

To explore symptoms, understanding of menopausal therapies, medication use and health-related behavior in women with and without premature menopause.

METHODS

Cross-sectional, questionnaire-based study involving a community-based sample of 77 women in Australia: 23 premenopausal, 25 with premature ovarian failure (POF) and 29 with medically induced premature menopause (MIPM).

RESULTS

The median (interquartile range) age of each group was: premenopausal = 29 (13) years, POF = 36 (8.0) years and MIPM = 38 (4.0) years (p < 0.001). The reported frequency of menopausal symptoms differed across the groups for difficulty sleeping (premenopausal = 26%, POF = 44%, MIPM = 69%, p = 0.01), some depression symptoms (premenopausal = 4.4-22%, POF = 20-25%, MIPM = 38-59%, p < 0.05), hot flushes (premenopausal = 4.4%, POF = 28%, MIPM = 59%, p < 0.001), sweating at night (premenopausal = 4.4%, POF = 20%, MIPM = 52%, p < 0.001) and loss of interest in sex (premenopausal = 17%, POF = 52%, MIPM = 54%, p = 0.02). More women with premature menopause than premenopausal women reported taking prescription medication (premenopausal = 52%, POF = 92%, MIPM = 86%, p = 0.002), perceived that hormone therapy (HT) was associated with increased breast cancer risk (premenopausal = 43%, POF = 56%, MIPM = 79%, p = 0.03) and that HT prevented fractures (premenopausal = 13%, POF = 56%, MIPM = 39%, p = 0.01). Most women reported not knowing risks/benefits of bioidentical hormone therapy (premenopausal = 86%, POF = 56%, MIPM = 75%, p = 0.06). Regarding health-related behavior around prevention and screening, varying rates of bone densitometry (premenopausal = 4.4%, POF = 64%, MIPM = 59%, p < 0.001), blood glucose testing (premenopausal = 39%, POF = 67%, MIPM = 57%, p = 0.16) and cholesterol testing (premenopausal = 22%, POF = 71%, MIPM = 54%, p = 0.003) were reported.

CONCLUSIONS

Differences in understanding of menopausal therapies and health-related behavior exist among women with premature menopause of differing etiology and premenopausal women. While perceived understanding of HT was greater than other therapies, targeted education is needed regarding specific risks/benefits of menopausal therapies and regarding preventive health screening after premature menopause.

Oxidative & nitrosative stress in depression: why so much stress?

Many studies support a crucial role for oxidative & nitrosative stress (O&NS) in the pathophysiology of unipolar and bipolar depression. These disorders are characterized inter alia by lowered antioxidant defenses, including: lower levels of zinc, coenzyme Q10, vitamin E and glutathione; increased lipid peroxidation; damage to proteins, DNA and mitochondria; secondary autoimmune responses directed against redox modified nitrosylated proteins and oxidative specific epitopes. This review examines and details a model through which a complex series of environmental factors and biological pathways contribute to increased redox signaling and consequently increased O&NS in mood disorders. This multi-step process highlights the potential for future interventions that encompass a diverse range of environmental and molecular targets in the treatment of depression.

Vitamin D and bone health: Epidemiologic studies

Allelic variation in the vitamin D receptor was the first non-structural gene to be associated with osteoporosis, and together with the effects of the vitamin D system on bone homeostasis, suggested that this vitamin might have a strong role in bone health. However, controversy exists regarding what level of serum 25-hydroxyvitamin D (25(OH)D) is optimal. Current data from biochemical, observational and randomized controlled trials (RCTs), indicate serum 25(OH)D levels of at least 50 nmol l(-1) are required for normalization of parathyroid hormone (PTH) levels, to minimize the risk of osteomalacia and for optimal bone cell function. The skeletal consequences of 25(OH)D insufficiency include secondary hyperparathyroidism, increased bone turnover and bone loss and an increased risk of minimal trauma fractures. In large scale epidemiological studies, serum 25(OH)D levels are associated with bone mineral density in both men and women. However, there is mixed evidence on the effectiveness of optimizing serum 25(OH)D levels for the prevention of bone loss and minimal trauma fractures in postmenopausal women and older men. There may be some benefit on primary fracture prevention for those who have inadequate serum levels of 25(OH)D, particularly in institutionalised elderly patients, but only when combined with calcium supplements. For optimal bone health, evidence from RCTs suggests vitamin D may be considered a threshold nutrient with few further bone benefits observed at levels of 25(OH)D above which PTH is normalized. An adequate calcium intake is also imperative to gain optimum benefit from an improved vitamin D status in those with insufficient 25(OH)D levels, with an increased calcium intake being associated with suppression of PTH levels.

Vitamin D deficiency among children with epilepsy in South Queensland

This study evaluated prevalence and risk factors for vitamin D deficiency among children with epilepsy on long-term antiepileptic drugs treated in South Queensland, Australia. Children with epilepsy seen in a tertiary neurology clinic were contacted requesting bone health blood tests during winter of 2011. Vitamin D deficiency was defined as 25-hydroxy vitamin D levels <20 ng/mL, and insufficiency between 21 and 29 ng/mL. One hundred thirty letters were sent, with 111 (85%) subsequently having blood tests performed. Vitamin D deficiency was identified in 24 (22%) of 111 and an additional 45 (41%) of 111 had vitamin D insufficiency. Multiple logistic regression analysis identified children on >2 antiepileptic drugs or with underlying genetic etiologies were more likely to have vitamin D deficiency. High proportion of children on long-term antiepileptic drugs in Queensland risk vitamin D deficiency and insufficiency despite living in the subtropics. Vitamin D monitoring and supplementation is important in the management of children on long-term antiepileptic drugs requiring tertiary care in Queensland.

Vitamin D intake in Australian adults and the modeled effects of milk and breakfast cereal fortification

OBJECTIVE

Vitamin D intake from foods or supplements is a safe and attractive means to improve vitamin D status of populations. The aim of this study was to help identify population subgroups that would benefit most from efforts to increase intake. To do so, we investigated which personal characteristics are associated with vitamin D intake in an Australian population and modeled possible effects of expanded food fortification practices.

METHODS

We investigated vitamin D intake in a population-based random sample of 785 adults, using a validated food frequency questionnaire, and assessed associations with personal and behavioral characteristics. We identified vitamin D food sources and modeled the hypothetical effects of blanket fortification of milk and breakfast cereals.

RESULTS

Average total vitamin D intake was 4.4 (±4.0) μg/g and below adequate intake for most participants in all age and sex subgroups. Higher intake was associated with being female, having a serious medical condition, energy intake below the median, and vitamin D supplement use (all P < 0.05). The "meat, fish, and eggs" food group contributed most to total vitamin D intake (51%), followed by dairy products and related foods (43%). If all milk and breakfast cereals were to be fortified with vitamin D, the average intake of vitamin D from foods would increase from 3.6 (±2.4) μg/d to 6.3 (±3.2) μg/d, with similar increases in all age and sex subgroups.

CONCLUSIONS

Vitamin D intake in Australia is generally below recommended levels, and few personal characteristics help to identify subgroups with low intake. Blanket vitamin D fortification of milk and breakfast cereals would substantially increase average vitamin D intake in Australian adults of all ages.

So depression is an inflammatory disease, but where does the inflammation come from?

BACKGROUND

We now know that depression is associated with a chronic, low-grade inflammatory response and activation of cell-mediated immunity, as well as activation of the compensatory anti-inflammatory reflex system. It is similarly accompanied by increased oxidative and nitrosative stress (O&NS), which contribute to neuroprogression in the disorder. The obvious question this poses is 'what is the source of this chronic low-grade inflammation?'

DISCUSSION

This review explores the role of inflammation and oxidative and nitrosative stress as possible mediators of known environmental risk factors in depression, and discusses potential implications of these findings. A range of factors appear to increase the risk for the development of depression, and seem to be associated with systemic inflammation; these include psychosocial stressors, poor diet, physical inactivity, obesity, smoking, altered gut permeability, atopy, dental cares, sleep and vitamin D deficiency.

SUMMARY

The identification of known sources of inflammation provides support for inflammation as a mediating pathway to both risk and neuroprogression in depression. Critically, most of these factors are plastic, and potentially amenable to therapeutic and preventative interventions. Most, but not all, of the above mentioned sources of inflammation may play a role in other psychiatric disorders, such as bipolar disorder, schizophrenia, autism and post-traumatic stress disorder.

A systematic review of vitamin D status in populations worldwide

Vitamin D deficiency is associated with osteoporosis and is thought to increase the risk of cancer and CVD. Despite these numerous potential health effects, data on vitamin D status at the population level and within key subgroups are limited. The aims of the present study were to examine patterns of 25-hydroxyvitamin D (25(OH)D) levels worldwide and to assess differences by age, sex and region. In a systematic literature review using the Medline and EMBASE databases, we identified 195 studies conducted in forty-four countries involving more than 168 000 participants. Mean population-level 25(OH)D values varied considerably across the studies (range 4·9-136·2 nmol/l), with 37·3 % of the studies reporting mean values below 50 nmol/l. The highest 25(OH)D values were observed in North America. Although age-related differences were observed in the Asia/Pacific and Middle East/Africa regions, they were not observed elsewhere and sex-related differences were not observed in any region. Substantial heterogeneity between the studies precluded drawing conclusions on overall vitamin D status at the population level. Exploratory analyses, however, suggested that newborns and institutionalised elderly from several regions worldwide appeared to be at a generally higher risk of exhibiting lower 25(OH)D values. Substantial details on worldwide patterns of vitamin D status at the population level and within key subgroups are needed to inform public health policy development to reduce risk for potential health consequences of an inadequate vitamin D status.

Make vitamin D while the sun shines, take supplements when it doesn't: a longitudinal, observational study of older adults in Tasmania, Australia

Low vitamin D status has been associated with a number of chronic conditions, particularly in older adults. The aim of this study was to identify how best to maintain optimum vitamin D status throughout the year in this high-risk population. The main objectives of the study were to assess seasonal vitamin D status; identify the main determinants of vitamin D status; determine if taking part in the study led to alterations in participant behaviour and vitamin D status. A longitudinal design across four consecutive seasons observed ninety-one 60–85 year old community-dwelling adults in Tasmania (41π S) over 13 consecutive months, with a follow-up assessment at next winter's end. Associations between solar UVB exposure, sun protection behaviours, dietary and supplemental vitamin D with serum 25(OH)D concentrations were assessed. Variation in serum 25(OH)D demonstrated an identical pattern to solar UVB, lagging 8–10 weeks. Serum 25(OH)D was positively associated with summer UVB (mean 15.9 nmol/L; 95%CI 11.8–19.9 nmol/L, p<0.001) and vitamin D supplementation (100–600 IU/day: 95%CI 10.2 nmol/L; 0.8–19.6 nmol/L; p = 0.03; 800 IU/day: 21.0 nmol/L; 95%CI 8.1–34.0 nmol/L; p = 0.001). Seasonal variation in serum 25(OH)D was greatly diminished in supplement users. The most common alteration in participant behaviour after the study was ingesting vitamin D supplements. Post-study vitamin D supplementation ℘800 IU/day was seven times more likely than during the study resulting in mean difference in serum 25(OH)D between supplement and non-supplement users of 30.1 nmol/L (95%CI 19.4–40.8 nmol/L; p<0.001). The main limitation was homogeneity of participant ethnicity. Solar exposure in summer and ingestion of vitamin D supplements in other seasons are the most effective ways of achieving and maintaining year-round vitamin D sufficiency in older adults in the Southern hemisphere. Vitamin D supplementation has greatest effect on vitamin D status if ingested during and after winter, i.e. between the autumn and spring equinoxes.

The ABC of vitamin D: a qualitative study of the knowledge and attitudes regarding vitamin D deficiency amongst selected population groups

Objective: In Australia, vitamin D supply in food is limited, and sun exposure is the main source of vitamin D. However skin cancer risk is high, and the need to gain some sun exposure for adequate vitamin D is challenging public health messages to use protection in the sun. The complex vitamin D public health message may be confusing the public and, in particular, those at highest risk for vitamin D deficiency. This study explored vitamin D and sun exposure attitudes, knowledge and practices of some groups considered at risk of vitamin D deficiency and those delivering healthy sun exposure messages to children. Method: 52 adults participated in six focus groups. Results: Results corroborated with previous research showing low levels of vitamin D knowledge. Individual and environmental barriers to receiving adequate sun exposure were also identified. Conclusions and Implications: The message advocating balanced sun exposure to produce adequate vitamin D needs to be made clearer and be more effectively communicated. Findings provide insights to aid development of appropriate public health messages for safe sun exposure and vitamin D, especially for vulnerable groups.

Seasonal variation in 25(OH)D at Aberdeen (57°N) and bone health indicators--could holidays in the sun and cod liver oil supplements alleviate deficiency?

Vitamin D has been linked with many health outcomes. The aim of this longitudinal study, was to assess predictors of seasonal variation of 25-hydroxy-vitamin D (25(OH)D) (including use of supplements and holidays in sunny destinations) at a northerly latitude in the UK (57°N) in relation to bone health indicators. 365 healthy postmenopausal women (mean age 62.0 y (SD 1.4)) had 25(OH)D measurements by immunoassay, serum C-telopeptide (CTX), estimates of sunlight exposure (badges of polysulphone film), information regarding holidays in sunny destinations, and diet (from food diaries, including use of supplements such as cod liver oil (CLO)) at fixed 3-monthly intervals over 15 months (subject retention 88%) with an additional 25(OH)D assessment in spring 2008. Bone mineral density (BMD) at the lumbar spine (LS) and dual hip was measured in autumn 2006 and spring 2007 (Lunar I-DXA). Deficiency prevalence (25(OH)D<25 nmol/L) was reduced in women who went on holiday to sunny destinations 3 months prior to their visit, compared to women who did not go on holidays [5.4% vs. 24.6% in Spring (p<0.001) and 3.8% vs. 25.6% in Winter (p = 0.001), respectively]. Similarly deficiency was lower amongst those who took CLO supplements compared to women that did not consume these supplements [2.0% vs. 23.7% in Spring (p = 0.001) and 4.5% vs. 24.8% in winter (p = 0.005), respectively]. There was no seasonal variation in CTX; 25(OH)D predicted a small proportion (1.8% variation) of LS BMD in spring 2007 [unstandardized β (SE): 0.039 (0.016), p = 0.017]. Seasonal variation of 25(OH)D had little effect on BMD and no effect on CTX. It appears that small increments in vitamin D (e.g. those that can be achieved by cod liver oil supplements of 5 µg/day) are sufficient to ensure that 25(OH)D is above 25 nmol/L for most people throughout the year. Similarly, holidays in sunny destinations show benefit.

Significant perturbation of vitamin D-parathyroid-calcium axis and adverse clinical outcomes in critically ill patients

PURPOSE

A prospective multicentre cohort study was conducted to determine the prevalence of hypovitaminosis D in adult critically ill patients, to characterize alterations in the parathyroid hormone (PTH)-vitamin D-calcium axis and to explore associations between hypovitaminosis D and adverse clinical outcomes.

METHODS

Demographic, disease severity scores and clinical outcome data were collected in 100 consecutive patients with expected intensive care unit (ICU) admission of at least 2 days. Levels of 25-hydroxyvitamin D (25-OH-D), 1,25-dihydroxyvitamin D (1,25-(OH)(2)-D), PTH and ionized calcium were measured on days 1, 3 and on day 7 or ICU discharge.

RESULTS

The prevalence of vitamin D insufficiency (25 nmol/L ≤ 25-OH-D ≤ 50 nmol/L) and deficiency (25-OH-D < 25 nmol/L) were 54 and 24 %, respectively, and levels did not recover during ICU stay. Admission 25-OH-D levels correlated with 1,25-(OH)(2)-D (R = 0.61, p = 0.001), Simplified Acute Physiology Score (SAPS-II) (R = -0.3, p = 0.01), Acute Physiology and Chronic Health Evaluation (APACHE-II) scores (R = -0.2, p = 0.05), but not calcium (R = 0.16, p = 0.11) or PTH (R = -0.11, p = 0.31) levels. Vitamin D deficiency was associated with fewer hospital-free days, OR 3.15 (1.18-8.43) in univariate analysis. Secondary hyperparathyroidism (PTH > 7 pmol/L) was observed in 37.5 % of hypocalcaemic and 32.5 % of vitamin D insufficient/deficient patients, and was associated with higher SAPS-II [43 (31.3-60) vs. 36 (30-43), p = 0.03].

CONCLUSIONS

Hypovitaminosis D and secondary hyperparathyroidism are highly prevalent in critically ill patients. Low vitamin D status persists during ICU stay and is associated with worse disease severity and fewer hospital-free days.

Seasonal reduction in vitamin D level persists into spring in NSW Australia: implications for monitoring and replacement therapy

CONTEXT

Seasonal variation in 25-hydroxyvitamin D [25OHD] status and its relationship to gender, age, socioeconomic and geographic determinants in Australians has not been described in large biomedical sampling cohorts.

OBJECTIVES

To analyse 25OHD levels in all primary tests undertaken consecutively in a 2-year period to determine the prevalence of 25OHD deficiency and its relation to patient setting, gender, age, season, urban or rural residency, socioeconomic status, latitude and longitude.

DESIGN

We assessed 24 819 ambulatory and inpatient samples taken from the largest reference laboratory in NSW, Australia between 01 July 2008 and 30 July 2010.

MAIN OUTCOME MEASURES

Serum 25OHD was measured using chemiluminescent immunoassay. Vitamin D deficiency was defined as 25OHD <50 nm.

RESULTS

Median 25OHD was 54 nm ranging from 63 nm in summer to 44 nm in spring and was lowest in inpatient women (49 nm) and highest in ambulatory men (64 nm). Mean 25OHD peaked in January (67 nm) and reached a nadir in August/September (39 nm). During summer, 36% subjects overall had a level below 50 nm, increasing to 58% in spring. The highest prevalence of deficiency occurred in female inpatients (42% in summer and 62% in spring). Factors associated with lower 25OHD included being tested in spring, an inpatient, female, aged 20-39 or >79 years, socioeconomically disadvantaged and from a major city.

CONCLUSION

This cross-sectional study demonstrates the extent and duration of 25OHD deficiency is greater than expected, and particular individuals are at higher risk. Our findings imply that supplementation guidelines need to be modified and strengthened.

Skeletal and hormonal responses to vitamin D supplementation during sunlight deprivation in Antarctic expeditioners

Sunlight deprivation results in vitamin D deficiency but serum vitamin D levels can be maintained above 50 nmol/L when supplemented with 50,000 IU at least every alternate month.

INTRODUCTION

Antarctic expeditioners are exposed to prolonged sunlight deprivation resulting in vitamin D deficiency. We hypothesised that monthly dosing of 50,000 IU vitamin D (~1,600 IU daily) will increase serum 25-hydroxyvitamin D (25(OH)D), suppress parathyroid hormone (PTH) and improve bone mineral density (BMD), 50,000 IU alternate months (~800 IU daily) will maintain these measures, while a single 50,000 IU dose pre-departure (~1,00 IU daily) will not be protective.

METHODS

This was a randomised double-blind study involving 110 healthy adults: 91 males, mean age 41 years (range 24-65 years) working in Antarctica for up to 12 months, who we administered 50,000 IU vitamin D3 monthly, alternate months or a single dose pre-departure. Serum 25(OH)D, PTH, osteocalcin, CTx and calcium were assessed at baseline, mid- and end of expedition. Proximal femur and lumbar spine BMD were assessed pre- and post-expedition.

RESULTS

Baseline 25(OH)D was 59 ± 14 nmol/L. By mid-expedition, 25(OH)D increased by 7 nmol/L in those supplemented monthly (p < 0.05) and remained unchanged in those supplemented in alternate months. In those given a single dose pre-departure, 25(OH)D decreased by 8 nmol/L (p < 0.05) and PTH increased by 27% (p < 0.09). Serum osteocalcin increased by ~22% in all groups but BMD remained unchanged. If serum 25(OH)D was >50 nmol/L at baseline, 25(OH)D was maintained above this level with all regimens. If 25(OH)D was <50 nmol/L at baseline, monthly or alternate month regimens were needed to achieve levels >50 nmol/L, the single pre-departure dose was ineffective.

CONCLUSION

During sunlight deprivation of up to 12 months, serum 25(OH)D levels can be maintained above 50 nmol/L when expeditioners are provided with 50,000 I U at least every alternate month.

A global representation of vitamin D status in healthy populations

PURPOSE

This paper visualizes the available data on vitamin D status on a global map, examines the existing heterogeneities in vitamin D status and identifies research gaps.

METHODS

A graphical illustration of global vitamin D status was developed based on a systematic review of the worldwide literature published between 1990 and 2011. Studies were eligible if they included samples of randomly selected males and females from the general population and assessed circulating 25-hydroxyvitamin D [25(OH)D] levels. Two different age categories were selected: children and adolescents (1-18 years) and adults (>18 years). Studies were chosen to represent a country based on a hierarchical set of criteria.

RESULTS

In total, 200 studies from 46 countries met the inclusion criteria, most coming from Europe. Forty-two of these studies (21 %) were classified as representative. In children, gaps in data were identified in large parts of Africa, Central and South America, Europe, and most of the Asia/Pacific region. In adults, there was lack of information in Central America, much of South America and Africa. Large regions were identified for which the mean 25(OH)D levels were below 50 nmol/L.

CONCLUSIONS

This study provides an overview of 25(OH)D levels around the globe. It reveals large gaps in information in children and adolescents and smaller but important gaps in adults. In view of the importance of vitamin D to musculoskeletal growth, development, and preservation, and of its potential importance in other tissues, we strongly encourage new research to clearly define 25(OH)D status around the world.

Prevalence of vitamin D deficiency and its determinants in Australian adults aged 25 years and older: a national, population-based study

OBJECTIVE

Vitamin D deficiency is recognized as a global public health problem, but the population-based prevalence of deficiency and its determinants in Australian adults is not known. This study evaluated the vitamin D status of Australian adults aged ≥25 years and risk factors associated with vitamin D deficiency in this population.

DESIGN AND PATIENTS

We studied a national sample of 11,247 Australian adults enrolled in the 1999/2000 Australian Diabetes, Obesity and Lifestyle (AusDiab) study drawn from 42 randomly selected districts throughout Australia.

MEASUREMENTS

Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were measured by immunoassay. Vitamin D deficiency was defined as a concentration <50 nmol/l. Information on demographic and lifestyle factors was derived from interview-administered questionnaires.

RESULTS

The mean serum 25(OH)D concentration was 63 nmol/l (95% CI: 59-67 nmol/l). Only 4% of the population had a level <25 nmol/l, but the prevalence of vitamin D deficiency (<50 nmol/l) was 31% (22% men; 39% women); 73% had levels <75 nmol/l. The prevalence of vitamin D deficiency increased significantly with age, was greater in women, in those of non-Europid origin, in the obese and those who were physically inactive and with a higher level of education. Deficiency was also more common during winter and in people residing in southern Australia (latitude >35°S); 42% of women and 27% of men were deficient during summer-autumn, which increased to 58% and 35%, respectively, during winter-spring.

CONCLUSION

Vitamin D deficiency is common in Australia affecting nearly one-third of adults aged ≥25 years. This indicates that strategies are needed at the population level to improve vitamin D status of Australians.

Determinants of vitamin D status among overweight and obese Puerto Rican adults

BACKGROUND/AIMS

Low vitamin D status is highly prevalent worldwide, and the major determinants are sun exposure and vitamin D intake. We aimed to measure vitamin D status in a sample of overweight/obese adults in Puerto Rico, an area with plenty of sun exposure, and relate it to vitamin D intake, sun exposure and body composition.

METHODS

Serum 25(OH)D levels (liquid chromatography-tandem mass spectrometry), body weight and fat (bioimpedance), vitamin D intake and sun exposure (questionnaires) were assessed. Analysis included age-adjusted correlations and multivariate regression.

RESULTS

In 98 subjects (66% females; 40-65 years), median serum 25(OH)D levels were 30.7 ng/ml (25-75th percentile 25.0-37.3); 55% had levels >30 ng/ml, 31% had levels between 20 and 30 ng/ml and 14% had levels <20 ng/ml. Total vitamin D intake was 180 IU/day (45-615), and the sun exposure score was 22 (17-27). After adjusting for gender, 25(OH)D levels were significantly correlated with vitamin D intake (r = 0.24, p = 0.018), the sum of sun exposure and vitamin D intake indices (r = 0.34, p = 0.001) and percent body fat (r = -0.25, p = 0.01). After adjusting for age, gender and percent body fat, the sum of sun exposure and vitamin D intake indices remained statistically associated with 25(OH)D levels (β = 1.5, p < 0.01).

CONCLUSIONS

In this group of overweight and obese individuals, 25(OH)D was significantly related to vitamin D intake, sun exposure and vitamin D intake indices and percent body fat.

Associations of Sun Exposure with 25-Hydroxyvitamin D and Parathyroid Hormone Levels in a Cohort of Hypertensive Patients: The Graz Endocrine Causes of Hypertension (GECOH) Study

Sunlight-induced vitamin D, synthesis in the skin is the major source of vitamin D, but data on the relationship of sun-related behaviour with vitamin D and parathyroid hormone (PTH) levels are relatively sparse. We evaluated whether habitual sun exposure is associated with 25-hydroxyvitamin D (25[OH]D) and PTH levels and whether there exist seasonal variations. We examined 111 hypertensive patients in Austria (latitude 47° N). Frequent sunbathing at home and outdoor sports were associated with higher 25(OH)D levels (P < 0.05 for both). Red or blond scalp hair as a child, memory of sunburns, preferring sunbathing, frequent stays on the beach or in open-air pools, and solarium use were associated with lower PTH levels (P < 0.05 for all). Multiple linear regression analyses including age, sex, and body mass index showed that sun exposure score was significantly associated with 25(OH)D (beta coefficient = 0.27; P = 0.004) and by trend with PTH (beta coefficient = -0.16; P = 0.09). These associations were more prominent in summer in which 25(OH)D levels were significantly higher compared to winter. Translation of these findings into recommendations for the prevention and treatment of vitamin D deficiency remains a challenge for the future.

A consensus statement for safety monitoring guidelines of treatments for major depressive disorder

OBJECTIVE

This paper aims to present an overview of screening and safety considerations for the treatment of clinical depressive disorders and make recommendations for safety monitoring.

METHOD

Data were sourced by a literature search using MEDLINE and a manual search of scientific journals to identify relevant articles. Draft guidelines were prepared and serially revised in an iterative manner until all co-authors gave final approval of content.

RESULTS

Screening and monitoring can detect medical causes of depression. Specific adverse effects associated with antidepressant treatments may be reduced or identified earlier by baseline screening and agent-specific monitoring after commencing treatment.

CONCLUSION

The adoption of safety monitoring guidelines when treating clinical depression is likely to improve overall physical health status and treatment outcome. It is important to implement these guidelines in the routine management of clinical depression.

Prescribing sunshine: a cross-sectional survey of 500 Australian general practitioners' practices and attitudes about vitamin D

This study aimed to assess the attitudes, practices and knowledge of general practitioners (GPs) with regards to vitamin D. A cross-sectional survey of a random sample of GPs stratified by location of practice (rural/remote or metropolitan) and employment status (full-time or part-time) in New South Wales (NSW), Australia was conducted. Of 500 respondents, 58.1% (95% CI 53.8-62.4) reported that up to 39% of their tested patients showed vitamin D deficiency or insufficiency and a further 37.7% (95% CI 33.5-41.9) of respondents said that over 40% of their patients were vitamin D insufficient. Vitamin D supplementation and advice to receive more natural sunlight were the most common ways vitamin D insufficiency was managed (97.1%; 95% CI 95.6-98.6 and 82%, 95% CI 78.6-85.4, respectively). Some gaps in knowledge were identified. Most respondents (64%; 95% CI 59.8-68.2) believed that a person of average sun sensitivity required 10 min of direct sun exposure during summer in peak UV time and a further 21.6% (95% CI 18.0-25.2) believed that people required 30 min of direct sun. A third of respondents (33.1%; 95% CI 29.0-37.2) advised their patients to use sun protection at all times during winter. In general, the attitude items showed that respondents expressed greater concern about vitamin D deficiency than skin cancer. The results reveal some confusion in general practice regarding vitamin D, sun exposure, sun protection and skin cancer risk. Some of the advice that GPs are offering may needlessly increase their patients' risk for vitamin D insufficiency or skin cancer.

The prevalence of vitamin D deficiency and relationship with fracture risk in older women presenting in Australian general practice

AIM

To investigate vitamin D status among older women and to explore relationships between vitamin D and fracture risk and vertebral fractures.

METHODS

A total of 267 general practitioners recruited 2466 women aged >70 years with no known osteoporosis or fragility fracture. Serum 25-hydroxy vitamin D (25(OH)D), bone mineral density by dual-energy X-ray absorptiometry (DXA) and vertebral fracture on thoracolumbar X-ray were determined.

RESULTS

A total of 2368 women, median age 76 years, provided data and of these 13% were on vitamin D supplements. 25(OH)D levels were available for 907 (44.1%) of those not taking vitamin D. 88.3% of these had a level below 75 nmol/L. Serum 25(OH)D was negatively associated with age (P = 0.003) and body mass index (P < 0.001), and positively associated with lower latitude, femoral neck DXA T-score (P = 0.044) and being Caucasian (P < 0.001).

CONCLUSIONS

The vitamin D status of community-dwelling older Australian women is inadequate, yet the use of supplements is low.

Vitamin D status of adults from tropical Australia determined using two different laboratory assays: implications for public health messages

We measured serum 25 hydroxyvitamin D [25(OH)D] levels of ambulatory adults in tropical Australia to determine whether it is appropriate to continue promoting sun-safety in this population. In August 2006 (winter), self-administered questionnaires were completed by 145 Meals-on-Wheels volunteers (49.3% male; mean age 57.8 ± 14.7 years; 76.6% response) from Townsville, Queensland (Latitude 19(o) S). Serum 25(OH)D was analyzed using two common assays. Mean levels were 68.3 (SD ± 18.7; range 26-142) by DiaSorin Radioimmunoassay and 83.0 (SD ± 30.8; range 30-184) by DiaSorin Liaison® one. No participants were 25(OH)D deficient (<25 nmol L(-1)). Nine participants (6.2%) had 25(OH)D levels between 25 and 50 nmol L(-1) (insufficient), by both methods (seven with a BMI ≥ 25). Twenty-eight participants (19.3%) had one result in the insufficient range and the other in the adequate range. Thus, almost all of these free-living adults in tropical Australia had adequate vitamin D levels at the end of winter. There was poor agreement between the two 25(OH)D assays. These results suggest it is appropriate to continue promoting sun-safe messages to the ambulatory Caucasian adult population of North Queensland, which has an extremely high incidence of skin cancer. The lack of agreement between the two assays is a concern. Few doctors are aware of this measurement issue.

Bioavailability of vitamin D3 in non-oily capsules: the role of formulated compounds and implications for intermittent replacement

OBJECTIVE

To evaluate the bioavailability of vitamin D in capsules as compared with oily drops in nuns living in a closed community with very low sun exposure.

METHODS

A randomized, 2 x 2 crossover, open clinical trial was conducted, with 18 nuns aged between 20 and 75 years. Samples were collected in the fasting state and at 4, 8, 12 and 24 hours following the administration of capsules and oily drops (both containing vitamin D3 66,000 UI plus vitamin A 13,200 UI) to determine serum 25 hydroxyvitamin D concentrations (25OHD), at baseline and 90 days after. The evaluation was based on the maximum concentration (Cmax) and area under the curve (AUC0-24).

RESULTS

The capsule formulation presented Cmax and AUC0-24, 5.78% and 0.76%, respectively, greater than the oily drops formulation.

CONCLUSION

Both formulations were within the limits for a bioequivalence study, namely C-90% for Cmax and AUC0-24, and the drugs were considered bioequivalent.

Transient bone marrow edema of the foot and ankle and its association with reduced systemic bone mineral density

BACKGROUND

Transient bone marrow edema in the foot and ankle is an uncommon condition that should be distinguished from early avascular necrosis, stress fracture, or bone bruise. The diagnosis is based on the clinical presentation of pain with weightbearing without a history of trauma, combined with typical findings on magnetic resonance imaging. The etiology is not known, but recent case reports have suggested a possible link to systemic osteoporosis. This study examined the relationship between transient bone marrow edema of the foot and ankle and low systemic bone mineral density.

MATERIAL AND METHODS

Over a period of 2 years, ten patients (eight women and two men) who were referred to our foot and ankle clinic were diagnosed as having transient bone marrow edema. Their mean age was 59 years. All underwent dual energy X-ray absorptiometry (DEXA) scan and were tested for serum vitamin D levels. The patients were treated with either a controlled ankle motion (CAM) walker or a stiff-soled postoperative shoe and all recovered in 5 to 10 months.

RESULTS

Four patients were found to have osteoporosis and five had osteopenia. Only one patient had normal bone density. Serum vitamin D levels were low in nine patients, and normal in one.

CONCLUSION

Our study found a strong association with transient bone marrow edema in the foot and ankle and low systemic bone mineral density, which appears to be due to a vitamin D deficiency. We recommend that, when TBME is diagnosed, patients should be referred for assessment and treatment of their bone mineral density.