Gestational Hypertension
Calcium
Supplementing with calcium may reduce the risk of gestational hypertension.Dose:
1,200 to 1,500 mg dailyCalciumCalcium deficiency has been implicated as a possible cause of GH.5,6 In two preliminary studies, women who developed GH were found to have significantly lower dietary calcium intake than did pregnant women with normal blood pressure.7,8 Calcium supplementation has significantly reduced the incidence of GH in preliminary studies9 and in many,9,11,12,13,14,15 though not all,16 double-blind trials. Calcium supplements may be most effective in preventing GH in women who have low dietary intake of calcium. The National Institutes of Health (NIH) recommends an intake of 1,200 to 1,500 mg of calcium daily during normal pregnancy.17 In women at risk of GH, studies showing reduced incidence have typically used 2,000 mg of supplemental calcium per day,18,19,9,11,13,15 without any reported maternal or fetal side effects.18,19 Nonetheless, many doctors continue to suggest amounts no higher than 1,500 mg per day.
Magnesium
Taking magnesium may prevent gestational hypertension or reduce its severity.Dose:
300 mg dailyMagnesiumMagnesium deficiency has also been implicated as a possible cause of GH.19,20,21 Dietary intake of magnesium is below recommended levels for many women during pregnancy.22,19 Magnesium supplementation has been reported to reduce the incidence of GH in preliminary19 and many double-blind trials.25,26,27 In addition to preventing GH, magnesium supplementation has also been reported to reduce the severity of established GH in one study.28 Amounts used in studies on GH range from 165 to 365 mg of supplemental magnesium per day.
Zinc
In one study, supplementing with zinc reduced the incidence of gestational hypertension in a group of pregnant Hispanic women who were not zinc deficient.Dose:
Refer to label instructionsZincZinc supplementation (20 mg per day) was reported to reduce the incidence of GH in one double-blind trial studying a group of low-income Hispanic pregnant women who were not zinc deficient.27