Does salt intake in the first two years of life affect the development of cardiovascular disorders in adulthood?

Excess salt intake impacts on blood pressure (BP) and the pathogenetic mechanisms of atherosclerosis predisposing to stroke and other cardiovascular disorders. The influence of salt starts early in life. Two randomized controlled trials in newborn infants suggest a direct association between dietary sodium intake and BP since the first few months of life. Newborn infants display aversion to the salt taste to develop a "preference" for salt only at age 2-3 years, in part in relation to post-natal events: this preference might be associated with later development of hypertension. The amount of sodium to be retained by an infant for proper physiological growth is largely covered by breast feeding (or low sodium formula milk) in the first six months, and later on by the gradual implementation of complementary feeding, without the need for any added salt upon food preparation. Given the lack of dose-dependence data, reference nutrient intakes (RNI) or adequate intakes (AI) for sodium have been established by national health institutions in various countries. The U.K. RNI was set at 242 mg a day for infants 0-6 months with gradual increase to 0.5 g up until age 3. The U.S. AI is somewhat lower for age 0-6 months but larger for age 1-3 years. According to a recent report, the average sodium intake in U.S. children is close to the AI up to age 2 years, to become progressively greater exceeding the Institute of Medicine recommendation later on.