Vitamin A status during the third trimester of pregnancy in Spanish women: influence on concentrations of vitamin A in breast milk.

We examined the relation between the vitamin A status of Spanish women during pregnancy and concentrations of vitamin A in breast milk. The subjects were 57 healthy, lactating women aged 18-35 y. Vitamin A intake was determined during the third trimester of pregnancy by using a 5-d dietary record that included a Sunday and by recording the quantities provided by supplements. HPLC was used to determine vitamin A concentrations in subjects' serum during the third trimester, in transitional breast milk (on days 13-14 of lactation), and in mature breast milk (on day 40). During the third trimester, 33.3% of subjects had vitamin A intakes from diet and supplements < 800 microg/d, the recommended value. These subjects had serum and breast milk vitamin A concentrations that were significantly lower than those of subjects who consumed greater quantities of the vitamin. Furthermore, subjects with serum vitamin A concentrations < 1.05 micromol/L during the third trimester (22.8%) had lower mean (+/- SD) concentrations of the vitamin in mature breast milk than did subjects with higher serum concentrations (1.8 +/- 1.2 micromol/L compared with 2.6 +/- 0.8 micromol/L; P < 0.05). These results show that vitamin A intake and serum vitamin A concentrations during pregnancy influence the composition of breast milk. Given that 12.3% of subjects had < 1.40 micromol vitamin A/L in mature breast milk, it seems advisable to follow and, if necessary, improve vitamin A status during pregnancy and lactation.