CALCIUM SUPPLEMENTATION DURING PREGNANCY
Numerous clinical trials of pregnant women have been conducted to assess the effects of calcium supplementation on PIH and pregnancy outcome. A meta-analysis by Bucher et al (20) was based on data from 2549 women in 14 randomized, controlled trials (considered the most scientifically sound of a total of 666 reviewed articles published between 1966 and 1994). Calcium supplementation in the range of 375–2000 mg (most studies closer to the upper boundary) resulted in a significant reduction in systolic blood pressure of 5.40 mm Hg (95% CI: −7.81, −3.00 mm Hg) and in diastolic blood pressure of 3.44 mm Hg (95% CI: −5.20, −1.68 mm Hg). Compared with placebo, calcium supplementation reduced the odds ratio for the development of gestational hypertension to 0.30 (95% CI: 0.17, 0.54) and of preeclampsia to 0.38 (95% CI: 0.22, 0.65). The findings were similar to those obtained in a previous meta-analysis of older clinical trials (21). Although some of the studies included in