Effect of Calcium and Vitamin D Supplementation on Blood Pressure

Abstract

Abstract-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 randomly 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: Ϫ0.05 to 0.49 mm Hg) and diastolic blood pressure (0.11 mm Hg; 95% CI: Ϫ0.04 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 T he role of calcium in the prevention and treatment of hypertension is controversial, despite decades of study. An overall healthy dietary pattern that is rich in calcium from low-fat dairy products, fruits, and vegetables has been shown to lower blood pressure substantially compared with a typical diet higher in fat and sodium and lower in calcium, magnesium, potassium, and fiber. 1-4 However, meta-analyses [5][6][7][8][9][10][11][12] and systematic reviews 13 of the epidemiological and clinical trial evidence regarding dietary intake of calcium as a single nutrient have generally concluded that the effect on systolic blood pressure (BP) lowering is small, on the order of 2 mm Hg. The effect on diastolic BP, if any, may be even smaller. Nevertheless, at a population level, sustained BP lowering of this degree by calcium supplementation could have important benefits on cardiovascular disease.:Although the relation between vitamin D and BP has been less studied, 2 small, short-term intervention studies suggest that vitamin D, either as ultraviolet light exposure or as an oral supplement, may lower BP. 14,15 In addition, the risk of incident hypertension was lower in a 4-year prospective study among men and women with higher plasma levels of 25(OH) vitamin D. 16 Animal studies have also shown that oral supplementation with vitamin D lowered BP in hypertensive rats; in this model vitamin D inhibited renin expression in the juxtaglomerular apparatus and inhibited smooth muscle proliferation. [17][18][19][20]

Long-term effect of calcium-vitamin D3 fortified milk on blood pressure and serum lipid concentrations in healthy older men

“…These findings are consistent with several short-term (Pan et al, 1993;Major et al, 2007) and long-term trials (Orwoll and Oviatt, 1990;Margolis et al, 2008) that reported that combined calcium-vitamin D supplementation did not lower blood pressure. To the best of our knowledge, our study is the longest trial to have assessed the blood pressure responses to additional calcium-vitamin D 3 , using food (milk) as a carrier.…”

Vitamin D and musculoskeletal health, cardiovascular disease, autoimmunity and cancer: Recommendations for clinical practice

“…In the Women's Health Initiative, an RCT including 36,282 postmenopausal women, vitamin D 3 plus calcium supplementation did not reduce blood pressure, nor the risk of developing hypertension over seven years of follow-up; however in this trial supplementation consisted only of 400 IU/day and adherence to supplementation was only around 60% [26]. A recent meta-analysis of 8…”

Maternal vitamin D status in pregnancy and adverse pregnancy outcomes in a group at high risk for pre‐eclampsia

“…19 The recently published Women's Health Initiative trial, which included 36 282 nonpregnant postmenopausal women randomised to supplementation with 1000 mg calcium and 10 lg (400 IU) vitamin D or placebo, showed no difference in systolic and diastolic BP or the development of hypertension over a median of 7 years of follow up. 20 The role of vitamin D in prevention and treatment of hypertensive disorders requires further evaluation.…”