Dietary recommendations and r and omized trials on vitamin D supplementation should evaluate whether increases in circulating 25-hydroxyvitamin D levels match expectations -- for instance , the average increases obtained by trials on vitamin D3 without concomitant calcium supplements
CONTEXT Few studies in subjects over 50 yr of age have evaluated the influence of variable doses of vitamin D supplementation on serum 25-hydroxyvitamin D levels .
OBJECTIVE We performed a meta- analysis of changes in circulating 25-hydroxyvitamin D level associated with vitamin D supplementation in Caucasian subjects over 50 yr old .
Calcium/vitamin D supplementation and coronary artery calcification in the Women's Health Initiative
Objective : Coronary artery calcified plaque is a marker for atheromatous plaque burden and predicts future risk of cardiovascular events . The relationship between calcium plus vitamin D ( calcium/D ) supplementation and coronary artery calcium ( CAC ) has not been previously assessed in a r and omized trial setting . We compared CAC scores after trial completion between women r and omized to calcium/vitamin D supplementation and women r and omized to placebo . Methods : In an ancillary sub study of women r and omized to calcium carbonate ( 1,000 mg of elemental calcium daily ) plus vitamin D3 ( 400 IU daily ) or placebo , nested within the Women 's Health Initiative trial of estrogen among women who underwent hysterectomy , we measured CAC with cardiac CT in 754 women aged 50 to 59 years at r and omization . Imaging for CAC was performed at 28 of 40 centers after a mean of 7 years of treatment , and scans were read central ly . CAC scores were measured by a central reading center with masking to r and omization assignments . Results : Posttrial CAC measurements were similar in women r and omized to calcium/D supplementation and those receiving placebo . The mean CAC score was 91.6 for women receiving calcium/D and 100.5 for women receiving placebo ( rank test P value = 0.74 ) . After adjustment for coronary risk factors , multivariate odds ratios for increasing CAC score cutpoints ( CAC > 0 , ≥10 , and ≥100 ) for calcium/D versus placebo were 0.92 ( 95 % CI , 0.64 - 1.34 ) , 1.29 ( 0.88 - 1.87 ) , and 0.90 ( 0.56 - 1.44 ) , respectively . Corresponding odds ratios among women with a 50 % or higher adherence to study pills and for higher levels of CAC ( > 300 ) were similar . Conclusions : Treatment with moderate doses of calcium plus vitamin D3 did not seem to alter coronary artery calcified plaque burden among postmenopausal women . Whether higher or lower doses would affect this outcome remains uncertain
Dietary recommendations and r and omized trials on vitamin D supplementation should evaluate whether increases in circulating 25-hydroxyvitamin D levels match expectations -- for instance , the average increases obtained by trials on vitamin D3 without concomitant calcium supplements
CONTEXT Few studies in subjects over 50 yr of age have evaluated the influence of variable doses of vitamin D supplementation on serum 25-hydroxyvitamin D levels .
OBJECTIVE We performed a meta- analysis of changes in circulating 25-hydroxyvitamin D level associated with vitamin D supplementation in Caucasian subjects over 50 yr old .