Optimum dose of vitamin D for disease prevention in older people: BEST-D trial of vitamin D in primary care.

This trial compared the effects of daily treatment with vitamin D or placebo for 1 year on blood tests of vitamin D status. The results demonstrated that daily 4000 IU vitamin D3 is required to achieve blood levels associated with lowest disease risks, and this dose should be tested in future trials for fracture prevention. INTRODUCTION: The aim of this trial was to assess the effects of daily supplementation with vitamin D3 4000 IU (100 µg), 2000 IU (50 µg) or placebo for 1 year on biochemical markers of vitamin D status in preparation for a large trial for prevention of fractures and other outcomes. METHODS: This is a randomized placebo-controlled trial in 305 community-dwelling people aged 65 years or older in Oxfordshire, UK. Outcomes included biochemical markers of vitamin D status (plasma 25-hydroxy-vitamin D [25[OH]D], parathyroid hormone [PTH], calcium and alkaline phosphatase), cardiovascular risk factors and tests of physical function. RESULTS: Mean (SD) plasma 25(OH)D levels were 50 (18) nmol/L at baseline and increased to 137 (39), 102 (25) and 53 (16) nmol/L after 12 months in those allocated 4000 IU, 2000 IU or placebo, respectively (with 88%, 70% and 1% of these groups achieving the pre-specified level of >90 nmol/L). Neither dose of vitamin D3 was associated with significant deviation outside the normal range of PTH or albumin-corrected calcium. The additional effect on 25(OH)D levels of 4000 versus 2000 IU was similar in all subgroups except for body mass index, for which the further increase was smaller in overweight and obese participants compared with normal-weight participants. Supplementation with vitamin D had no significant effects on cardiovascular risk factors or on measures of physical function. CONCLUSIONS: After accounting for average 70% compliance in long-term trials, doses of 4000 IU vitamin D3 daily may be required to achieve plasma 25(OH)D levels associated with lowest disease risk in observational studies.

Vascular and upper gastrointestinal effects of non-steroidal anti-inflammatory drugs: meta-analyses of individual participant data from randomised trials.

BACKGROUND: The vascular and gastrointestinal effects of non-steroidal anti-inflammatory drugs (NSAIDs), including selective COX-2 inhibitors (coxibs) and traditional non-steroidal anti-inflammatory drugs (tNSAIDs), are not well characterised, particularly in patients at increased risk of vascular disease. We aimed to provide such information through meta-analyses of randomised trials. METHODS: We undertook meta-analyses of 280 trials of NSAIDs versus placebo (124,513 participants, 68,342 person-years) and 474 trials of one NSAID versus another NSAID (229,296 participants, 165,456 person-years). The main outcomes were major vascular events (non-fatal myocardial infarction, non-fatal stroke, or vascular death); major coronary events (non-fatal myocardial infarction or coronary death); stroke; mortality; heart failure; and upper gastrointestinal complications (perforation, obstruction, or bleed). FINDINGS: Major vascular events were increased by about a third by a coxib (rate ratio [RR] 1·37, 95% CI 1·14-1·66; p=0·0009) or diclofenac (1·41, 1·12-1·78; p=0·0036), chiefly due to an increase in major coronary events (coxibs 1·76, 1·31-2·37; p=0·0001; diclofenac 1·70, 1·19-2·41; p=0·0032). Ibuprofen also significantly increased major coronary events (2·22, 1·10-4·48; p=0·0253), but not major vascular events (1·44, 0·89-2·33). Compared with placebo, of 1000 patients allocated to a coxib or diclofenac for a year, three more had major vascular events, one of which was fatal. Naproxen did not significantly increase major vascular events (0·93, 0·69-1·27). Vascular death was increased significantly by coxibs (1·58, 99% CI 1·00-2·49; p=0·0103) and diclofenac (1·65, 0·95-2·85, p=0·0187), non-significantly by ibuprofen (1·90, 0·56-6·41; p=0·17), but not by naproxen (1·08, 0·48-2·47, p=0·80). The proportional effects on major vascular events were independent of baseline characteristics, including vascular risk. Heart failure risk was roughly doubled by all NSAIDs. All NSAID regimens increased upper gastrointestinal complications (coxibs 1·81, 1·17-2·81, p=0·0070; diclofenac 1·89, 1·16-3·09, p=0·0106; ibuprofen 3·97, 2·22-7·10, p<0·0001; and naproxen 4·22, 2·71-6·56, p<0·0001). INTERPRETATION: The vascular risks of high-dose diclofenac, and possibly ibuprofen, are comparable to coxibs, whereas high-dose naproxen is associated with less vascular risk than other NSAIDs. Although NSAIDs increase vascular and gastrointestinal risks, the size of these risks can be predicted, which could help guide clinical decision making. FUNDING: UK Medical Research Council and British Heart Foundation.