[Vitamin A concentration in maternal milk: the effect of intake and serum levels of vitamin A during the third trimester of pregnancy].

Background: Breast fed newborns depend on maternal milk for their supply of vitamin A. A deficiency of this vitamin is associated with increased morbidity and mortality. The present study investigates whether the nutritional status of the mother during pregnancy conditions vitamin A levels in maternal milk.

Subjects And Method: 57 healthy, lactating mothers aged between 18 and 35 were studied. Vitamin A intake during the third trimester of pregnancy was recorded using a 5 day dietary record (including a Sunday) and by registering nutrients supplied by supplements. Vitamin A levels in maternal serum during this stage of pregnancy and in transition milk (days 13-14 of lactation) and mature milk (day 40 of lactation) were determined using high performance liquid chromatography.

Results: The effect of vitamin A intake during pregnancy on maternal milk composition was particularly noticeable in mothers with intakes below recommended values. These subjects showed lower vitamin A concentrations in transition (60.9 micrograms/dl) and mature milk (47.2 micrograms/dl) than those with adequate intakes of this vitamin (90.8 micrograms/dl and 79.2 micrograms/dl, respectively). Subjects with serum vitamin A concentrations below 30 micrograms/dl (22.8%) during the third trimester of pregnancy also showed lower levels of the vitamin in mature milk (50 micrograms/dl) compared with those with higher serum levels (74.8 micrograms/dl).

Conclusions: Diet and the nutritional status of vitamin A during pregnancy seem to condition concentrations of this vitamin in maternal milk. This, in turn, will affect the intake of vitamin A by the newborn. Given that deficiencies were detected both in serum and in maternal milk, the monitorization of the vitamin A levels in pregnant women is recommendable and if necessary, would be improved.