The influence of smoking on vitamin C status during the third trimester of pregnancy and on vitamin C levels in maternal milk

Objective: The aim of the present investigation was to determine the differences in vitamin C status of 57 Spanish women smokers (S) and nonsmokers (N) in their third trimester of pregnancy, and the concentrations of vitamin C in their milk. Methods: Vitamin C intake during the third trimester was determined by recording the consumption of foods over a fi-day period (including a Sunday) and by registering vitamin C provided by dietary supplements. Vitamin C levels in maternal serum during this stage of pregnancy and in transition (days 13 to 14 of lactation) and mature milk (day 40 of lactation) were determined colorimetrically. Subjects also answered a questionnaire on their smoking habits during pregnancy. Results: S subjects (n=16) showed a lower intake of fruits, vegetables and vitamin C than did N subjects (n=41), though these differences were not significant (17.1% of N subjects and 31.2% of S subjects took less than 80 mg of vitamin C per day). Neither were any differences found between the two groups in serum vitamin C levels. However, N subjects showed significantly greater vitamin C levels in both transition and mature milk (431.6+/-296.5 mu mol/L and 496.1+/-325.6 mu mol/L, respectively for N subjects, and 233.7+/-202.9 mu mol/L and 241.3+/-293.1 mu mol/L for S subjects). Further investigations are necessary to determine the clinical consequences of these observations, though it is already known that maternal smoking favors peroxidation events in newborn infants. Conclusions: if the concentration of antioxidants (vitamin C) in smokers' breast milk is also lower, this might aggravate the peroxidation problems of their newborn.