Calcium/vitamin D supplementation and coronary artery calcification in the Women's Health Initiative

What this study found

Calcium/vitamin D supplementation did not change coronary artery calcium burden compared with placebo. In 754 participants, mean Agatston CAC scores were 91.6 vs 100.5 (p=0.74). Multivariate analyses showed similar CAC distributions between groups; odds ratios for CAC >0, ≥10, and ≥100 were not significantly different (0.92, 1.29, 0.90; all p>0.05). In adherent participants, results were similar; a borderline increase in mild CAC (10–100) was observed in one analysis (OR 1.59; 95% CI 1.00–2.53) but not robust across analyses. Conclusion: Moderate-dose calcium and vitamin D supplementation…

Study & population

Ancillary substudy of WHI-CACS; postmenopausal women aged 50-59 with hysterectomy; double-blind, placebo-controlled randomized trial of calcium/vitamin D supplementation; CAC measured by cardiac CT in 754 women.

Intervention

Calcium carbonate with elemental calcium 1000 mg daily plus vitamin D3 400 IU daily, taken orally in two divided doses, for seven years.

Key limitation

Not all randomized participants underwent CAC assessment; some stopped taking study pills before completion; interval between end of treatment and CAC imaging could attenuate associations; prerandomization CAC data were not available; 25(OH) vitamin D was not measured; potential residual confounding; findings may not…

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