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

UNLABELLED: 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.

Supportive care for patients with gastrointestinal cancer.

BACKGROUND: Supportive care has traditionally been given to optimise the comfort of patients and their ability to function, as well as to minimise the side-effects of anti-cancer treatments. The scope of modern comprehensive supportive care however is broadening and covers not only specific palliative treatment but non-tumour specific treatment such as social, psychological and spiritual support. In oncology, best supportive care (BSC) has been used as a comparator arm of randomised controlled trials in chemotherapy. However the BSC arm is usually not well defined and its evaluation is therefore difficult because of the heterogeneity of the definitions. A systematic review was undertaken of the evidence from all RCTs of gastrointestinal cancers (includes gastrointestinal/gastric, colorectal/colon cancer but excludes pancreatic cancer trials) which include a BSC/SC arm. OBJECTIVES: 1. To examine the effectiveness/outcomes of best supportive care interventions versus cancer therapies for gastrointestinal cancer trials;2. To determine whether trials containing best supportive care include a definition of this. SEARCH STRATEGY: Electronic databases, grey literature sources, citation searching and reference checking, handsearches of journals and discussion with experts were used to identify potentially eligible trials from both published and unpublished sources. SELECTION CRITERIA: RCTs comparing BSC/SC versus anticancer therapies in patients with gastrointestinal cancers. DATA COLLECTION AND ANALYSIS: Four RCTs were found and reviewed. Because of the heterogeneity of studies, a meta-analysis was not attempted. Data was extracted from the included papers and the quality of each included study was assessed using the Jadad 1996 and Rinck 1997 methods of assessing the quality of RCTs. MAIN RESULTS: Data from four trials (483 patients) were included. Due to the heterogeneity of studies (in terms of populations studied, the interventions used, the variety of outcomes and assessments used) it was not possible to make direct comparisons between the studies. The primary outcome in all four trials was survival, in spite of patients with advanced/metastatic gastrointestinal cancer having a poor prognosis, and the interventions being primarily palliative. REVIEWERS' CONCLUSIONS: Overall the results show that for most of the trials included in this review, certain forms of chemotherapy plus supportive care improve both survival and quality of life in patients with gastrointestinal cancer (gastric and colorectal cancers) compared to receiving supportive care alone. Trials involving BSC/SC in patients with advanced gastrointestinal cancer require careful evaluation. Oncologists and researchers alike should strive for improvements in trial design and reporting. Future trials should focus on clearer definitions of supportive care. The EORTC definition of supportive care can be used as a guide. BSC/SC trials should use standardised validated outcome measures for symptom control, quality of life, toxicity and other useful palliative measures.