The optimal dose of vitamin D to optimize bone metabolism in the elderly is unclear. We tested the hypothesis a vitamin D, at a dose higher than recommended by the Institute of Medicine (IOM), has a beneficial effect on bone remodeling and mass. In this double blind trial we randomized 257 overweight elderly subjects to receive 1000 mg of elemental calcium citrate/day, and the daily equivalent of 3,750IU/day or 600 IU/day of vitamin D3 for one year. The subjects’ mean age was 71±4 years, body mass index 30±4 kg/m2, 55% were women, and 222 completed the 12-months follow-up. Mean serum 25 hydroxy-vitamin D (25OHD) was 20 ng/ml, and rose to 26 ng/ml in the low dose, and 36ng/ml in the high dose arm, at one year (p<0.05). Plasma parathyroid hormone, osteocalcin, and C-terminal telopeptide (Cross Laps) levels decreased significantly by 20–22% in both arms, but there were no differences between the two groups for any variable, at 6 or 12 months, with the exception of serum calcitriol that was higher in the high-dose group at 12 months. Bone mineral density (BMD) increased significantly at total hip and lumbar spine, but not femoral neck, in both arms, while subtotal body BMD increased in the high-dose group only, at one year. However, there were no significant differences in percent change BMD between the 2 arms at any skeletal site. Subjects with serum 25OHD below 20 ng/ml and PTH level above 76 pg/ml, showed a trend for higher BMD increments at all skeletal sites, in the high-dose group, that reached significance at the hip. Adverse events were comparable in the two study arms. This controlled trial demonstrates little additional benefit in vitamin D supplementation at a dose exceeding the IOM recommendation of 600IU/day on BMD and bone markers, in overweight elderly individuals.
The witchesÕ broom disease caused by the fungus Crinipellis perniciosa is the main limiting factor for cocoa production in South America and the Caribbean. In Brazil, this disease affects almost all cocoa-growing regions, causing serious economic, social and ecological damage. The aim of this study was to map genomic regions associated with resistance to C. perniciosa using an F 2 population derived from a cross between ÔScavina-6Õ (resistant) and ÔICS-1Õ (susceptible). The phenotypic index was determined as the average number of vegetative witchesÕ brooms per canopy area of each plant, the witchesÕ brooms were counted and eliminated during six field evaluations between May 1998 and August 1999. A total of 124 random amplified polymorphic DNA (RAPD) and 69 amplified fragment length polymorphism (AFLP) markers were mapped along 25 linkage groups covering 1713 cM of cocoa genome. After employing single factor and composite interval mapping analyses, a major quantitative trait loci (QTL) flanked by the marker AV14.940 was identified in the linkage group 11, explaining almost 35% of the resistance to witchesÕ broom. The present result suggests that this QTL acts as a major dominant component of resistance to this pathogen, with great potential for use in marker-assisted selection procedures in cocoa breeding programmes.
A change in 25-OHD assays has a significant impact on results, patient classification, and treatment recommendations. Such variability cannot be ignored when deriving and applying vitamin D guidelines. It also renders universal assay standardization a pressing call.
Lead and cadmium exposures are two old problems with modem prevalence. Lead and cadmium are widely dispersed in the environment, and exposure to either element can give rise to a number of adverse health effects due to their toxicity after accumulation in multiple organs in the body. While lead poisoning remains a dominant health problem in the United States despite the decline in occupational and environmental exposure in the
Vitamin D3 at 3750 IU/d did not improve HOMA-IR compared with the Institute of Medicine Recommended Dietary Allowance of 600 IU/d in elderly overweight individuals. This trial was registered at clinicaltrials.gov as NCT01315366.
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