Vitamin D dose requirements for fracture prevention

Current Management of Pediatric Vitiligo

Vitiligo is a common inflammatory disorder with worldwide prevalence of 0.4-2 % of the population, with half of cases beginning in childhood. The management of childhood vitiligo should be tailored to avoid negative effects on the overall growth and psychological development of the patient. Therapy of vitiligo in childhood is chosen based on the location of the lesions, lesion age, and extent of lesions in the context of the child's age and the developmental status of the child. There are four age categories in childhood vitiligo: [1] infantile and toddler (rare) (ages 0-3 years), [2] ages 4-8 years, [3] ages 9-12 years, and [4] 13+ years of age, based on developmental stage, psychological maturation, and ability to comply or participate in therapy. These categories are also differentiated psychologically by susceptibility to bullying, self-image development, and personal concern with lesion appearance, which increases with time. Intervention is advisable in cases with facial and leg involvement due to prominence of lesions and cosmetic defect. Medical interventions are largely the usage of topical therapies including corticosteroids and calcineurin inhibitors, some vitamin therapy (oral and topical vitamin D), and judicious introduction of phototherapy sources based on age and severity. Screening and appropriate subspecialist referral for co-morbidities (e.g., thyroid disease, celiac disease, psychological distress, and vitamin D deficiency) may enhance overall health. Cosmesis and camouflage are generally safe in childhood and have been noted to improve overall quality of life in this grouping. Genetic transmission of vitiligo is minimal at 5-6 % in first-degree relatives. This article reviews the therapeutics of pediatric vitiligo from the perspective of developmental stages and response to therapy.

A case study of discordant overlapping meta-analyses: vitamin d supplements and fracture

BACKGROUND

Overlapping meta-analyses on the same topic are now very common, and discordant results often occur. To explore why discordant results arise, we examined a common topic for overlapping meta-analyses- vitamin D supplements and fracture.

METHODS AND FINDINGS

We identified 24 meta-analyses of vitamin D (with or without calcium) and fracture in a PubMed search in October 2013, and analysed a sample of 7 meta-analyses in the highest ranking general medicine journals. We used the AMSTAR tool to assess the quality of the meta-analyses, and compared their methodologies, analytic techniques and results. Applying the AMSTAR tool suggested the meta-analyses were generally of high quality. Despite this, there were important differences in trial selection, data extraction, and analytical methods that were only apparent after detailed assessment. 25 trials were included in at least one meta-analysis. Four meta-analyses included all eligible trials according to the stated inclusion and exclusion criteria, but the other 3 meta-analyses "missed" between 3 and 8 trials, and 2 meta-analyses included apparently ineligible trials. The relative risks used for individual trials differed between meta-analyses for total fracture in 10 of 15 trials, and for hip fracture in 6 of 12 trials, because of different outcome definitions and analytic approaches. The majority of differences (11/16) led to more favourable estimates of vitamin D efficacy compared to estimates derived from unadjusted intention-to-treat analyses using all randomised participants. The conclusions of the meta-analyses were discordant, ranging from strong statements that vitamin D prevents fractures to equally strong statements that vitamin D without calcium does not prevent fractures.

CONCLUSIONS

Substantial differences in trial selection, outcome definition and analytic methods between overlapping meta-analyses led to discordant estimates of the efficacy of vitamin D for fracture prevention. Strategies for conducting and reporting overlapping meta-analyses are required, to improve their accuracy and transparency.

The short-term impact of vitamin D-based hip fracture prevention in older adults in the United Kingdom

PURPOSE

Vitamin D is a relatively inexpensive drug yet an important hormone in terms of calcium and bone homeostasis. Treatment with vitamin D is associated with reduced fracture risk particularly in an elderly population. Therefore, we assessed the budgetary impact of routine prescription of 800 IU daily colecalciferol on hip fracture among older adults in the United Kingdom.

METHODS

Using meta-analysis findings for treatment effect and UK-estimates of incidence, we performed a health economic evaluation of treating the UK population aged 65 and over with 800 IU of vitamin D daily, assessing the impact upon hip fracture costs using incremental attributable costs and excess mortality for a range of age- gender-based treatment strategies.

RESULTS

Using only a 1-year horizon, considering only reduction in hip fracture, prescribing colecalciferol 800 IU daily to all adults aged 65 and over, could reduce the number of incident hip fractures from 65,400 to 45,700, saving almost 1,700 associated deaths, whilst saving the UK taxpayer £22 million.

CONCLUSIONS

As the UK government seeks to reduce public expenditure in all sectors, investment in prescribed prophylactic colecalciferol 800 IU therapy for adults aged 65 and over is likely to yield cost savings through reduction hip fracture alone in the first year.

Serum 25(OH)D response to vitamin D3 supplementation: a meta-regression analysis

OBJECTIVE

The aim of this study was to review factors that influence serum 25(OH)D when patients are given vitamin D supplements.

METHODS

From a comprehensive search of all randomized controlled clinical trials with vitamin D3 supplementation available on PubMed up to November 2011, we selected 33 with 43 treatment arms that included at least 30 adult participants. The achieved pooled mean difference (PMD) and 95% confidence intervals (CIs) were calculated using the random-effects models. Meta-regression and subgroup analyses were performed for prespecified factors, including dose, duration, baseline serum 25(OH)D, and age.

RESULTS

With a mean baseline serum 25(OH)D of 50.4 nmol/L, PMD was 37 nmol/L (95% CI, 33-41) with significant heterogeneity among studies. Dose (slope: 0.006; P < 0.001), trial duration (slope: 0.21; P < 0.001), baseline serum 25(OH)D (slope: -0.19; P < 0.001), and age (slope: 0.42; P < 0.001) independently influenced vitamin D response. Similar results were found in studies with a mean baseline serum 25(OH)D <50 nmol/L. In subgroup analyses, the PMD was higher with doses ≥800 IU/d (39.3 nmol/L) after 6 to 12 mo (41.7 nmol/L), with baseline 25(OH)D <50 nmol/L (39.6 nmol/L), and in adults aged >80 y (40.5 nmol/L).

CONCLUSION

This meta regression indicates that a higher increase in serum levels of 25(OH)D in adults is found with a dose of ≥800 IU/d, after at least 6 to 12 mo, and even when baseline 25(OH)D is low and in adults >80 y.

Vitamin D: do we get enough? A discussion between vitamin D experts in order to make a step towards the harmonisation of dietary reference intakes for vitamin D across Europe

On September 29, 2011, acknowledged experts in the field of vitamin D, mainly European, were brought together in order to discuss the recent scientific advances in relation to vitamin D: the current requirements and associations with various health outcomes. In this article, the discussions resulting from the meeting are summarized.

INTRODUCTION

Several groups at risk for developing vitamin D insufficiency have been identified. Accordingly, reviews indicate that a significant percentage of the population worldwide have serum 25-hydroxyvitamin D levels below 50 nmol/l. In addition to the role of vitamin D in bone health, recent studies suggest that it may play a pivotal role in other systems, e.g., the cardiovascular system, pancreas, muscle, immune system and brain. Most evidence, however, is obtained from observational studies and yet inconclusive.

METHODS

To exchange and broaden knowledge on the requirements for vitamin D and its effect on various health outcomes, a workshop entitled "Vitamin D Expert Meeting: Do we get enough?", was organized.

RESULTS

Despite low vitamin D levels worldwide, consensus on the definition of deficiency is not yet reached. In order to define cut-off points for vitamin D whilst taking into account extraskeletal health effects, randomized controlled trials in these fields are warranted. The experts do emphasize that there is evidence to suggest an important role for vitamin D in the maintenance of optimal bone health at all ages and that vitamin D supplementation, in most studies co-administered with calcium, reduces fracture risk in the senior population.

CONCLUSION

To reach a serum 25-hydroxyvitamin D level of 50 nmol/l older adults aged ≥65 years are therefore recommended to meet a mean daily vitamin D intake of 20 μg (800 IU), which is best achieved with a supplement.