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 .
Effect of Calcium and Vitamin D Supplementation on Blood Pressure: The Women's Health Initiative Randomized Trial
Experimental and epidemiological studies suggest that calcium and vitamin D supplements may lower  blood pressure . We examined the effect of calcium plus vitamin D supplementation on blood pressure and the incidence of hypertension in postmenopausal women . The Women 's Health Initiative Calcium/Vitamin D Trial r and omly assigned 36 282 postmenopausal women to receive 1000 mg of elemental calcium plus 400 IU of vitamin D3 daily or placebo in a double-blind fashion . Change in blood pressure and the incidence of hypertension were ascertained . Over a median follow-up time of 7 years , there was no significant difference in the mean change over time in systolic blood pressure ( 0.22 mm Hg ; 95 % CI : −0.05 to 0.49 mm Hg ) and diastolic blood pressure ( 0.11 mm Hg ; 95 % CI : −0.04 to 0.27 mm Hg ) between the active and placebo treatment groups . This null result was robust in analyses accounting for nonadherence to study pills and in baseline subgroups of interest , including black subjects and women with hypertension or high levels of blood pressure , with low intakes of calcium and vitamin D or low serum levels of vitamin D. In 17 122 nonhypertensive participants at baseline , the hazard ratio for incident hypertension associated with calcium/vitamin D treatment was 1.01 ( 95 % CI : 0.96 to 1.06 . ) In postmenopausal  women , calcium plus vitamin D3 supplementation did not reduce either blood pressure or the risk of developing hypertension over 7 years of follow-up
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 .