Low sodium diet in pregnancy: effects on maternal nutritional status.

In the present study, besides the effect on blood pressure, the effects of a low sodium diet in pregnancy on maternal energy and nutrient intake, calcium metabolism, zinc and magnesium status, weight gain and body fat storage were investigated. No effect of the low sodium diet in pregnancy on the course of blood pressure and the incidence of hypertensive disorders was observed. The reduction in sodium intake also caused a significant reduction in the intake of energy, protein, carbohydrates, fat, calcium, zinc, magnesium, iron and cholesterol. The reduced intake of calcium, zinc and magnesium in the women on the low sodium diet did not result in significant changes in circulating total calcium, ionized calcium, parathyroid hormone, zinc, alkaline phosphatase or magnesium, probably because of homeostatic adaptations by the kidneys. In the women on the low sodium diet non-significant reductions in weight gain (1.5 kg) and fat mass gain (0.9 kg) over pregnancy were observed. These reductions in weight and fat mass gain were more pronounced (3.4 kg (P = 0.003) and 1.3 kg (P = 0.15), respectively) when only the data of the women with good compliance were analyzed. The use of a low sodium diet in pregnancy did not have significant effects on infant birth weight, placental weight or other pregnancy outcome variables.