Influence of smoking on vitamin E status during the third trimester of pregnancy and on breast-milk tocopherol concentrations in Spanish women

Abstract

Concentrations of antioxidants in breast milk probably define the degree of protection it can offer against peroxidation. The aim of the present investigation was to determine the differences in vitamin E status of Spanish women smokers and nonsmokers in their third trimester of pregnancy and the concentrations of tocopherol in their milk. Vitamin E intake was determined during the third trimester of pregnancy by using a 5-d dietary record (including a Sunday) and by recording the quantities provided by supplements. HPLC was used to determine vitamin E 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 of lactation. Subjects also answered a questionnaire about their smoking habits during pregnancy. Subjects were grouped as nonsmokers (71.9%; n = 41) or smokers (28.1%; n = 16). Although vitamin E intake was somewhat greater in nonsmokers, the difference was not significant. Ratios of vitamin E to polyunsaturated fatty acids were practically the same in both groups. The use of vitamin E supplements was limited and did not modify the results of the study. No significant differences in these serum indexes were found between smokers and nonsmokers, and no subject had deficient serum vitamin E concentrations. However, vitamin E concentrations in mature milk were significantly lower in smokers than in nonsmokers. Although it is already known that maternal smoking favors peroxidation events in newborns, if the concentration of antioxidants (vitamin E) in smokers' breast milk is also lower, it might aggravate the peroxidation problems of their newborns.