CONCLUSION
Evidence suggests a possible beneficial effect of dietary calcium in the prevention and treatment of PIH. However, contradictions persist in calcium intervention studies of pregnant women. A definitive understanding of the mechanism whereby dietary calcium influences blood pressure is also lacking. At present, there is not enough evidence to support routine calcium supplementation of all pregnant women. However, high-risk groups, such as pregnant teens, populations with inadequate calcium intake, and women at risk of developing PIH, may benefit from consuming additional dietary calcium. Future research is necessary to identify women who stand to benefit most from increasing their calcium intake. It may also be of interest to determine whether women with PIH have impaired calcium absorption, whether the timing of calcium supplementation is important [eg, early in pregnancy when alterations in calcium homeostasis are already beginning to occur (6) as opposed to in mid pregnancy when most clinical trials begin supplementation], and whether consumption of dairy foods has a larger impact than does supplemental calcium alone.