[Alpha-tocopherol level in serum and colostrum of breastfeeding women and association with maternal variables].
OBJECTIVE
To determine the nutritional status of vitamin E in breastfeeding women through the analysis of alpha-tocopherol concentration in serum and colostrum, to analyze its relation with maternal variables and to determine the prevalence of vitamin E deficiency in these women.


METHODS
The study included 103 mothers who were classified according to maternal variables: age, nutritional status before pregnancy, gestational weight gain, parity and mode of delivery. Colostrum and serum samples were collected under fasting conditions in the immediate postpartum period. Alpha-tocopherol was analyzed by high performance liquid chromatography (HPLC). A serum cutoff of 697.7 μg/dL was adopted to define the nutritional status of vitamin E. Statistical analysis was performed with the Student's t test for independent samples and Pearson's correlation. Differences were significant when p<0.05.


RESULTS
The average concentration of alpha-tocopherol was 1.125±551.0 μg/dL in colostrum and 1,138.6±346.0 μg/dL in serum, indicating adequate biochemical nutritional status. However, when analyzing the mothers individually, a 16% rate of subclinical vitamin E deficiency was detected. Women undergoing cesarean delivery had significantly higher alpha-tocopherol levels in colostrum (1.280±591 μg/dL) compared with those undergoing normal delivery (961.7±370 μg/dL) (p<0.05). It was found that mothers who were overweight before pregnancy had higher vitamin concentration in colostrum (1,331.5±548 μg/dL) when compared to underweight women (982.1±374 μg/dL) or women of normal weight (992.3±346 μg/dL) (p<0.05). However, the other variables were not associated with alpha-tocopherol in colostrum. Moreover, no variable showed association with vitamin E levels in maternal serum and no correlation was demonstrated between the alpha-tocopherol levels in serum and in milk.


CONCLUSIONS
Despite the diagnosis of satisfactory nutritional status, breastfeeding women showed significant risk of subclinical vitamin E deficiency. We suggest that the concentration of alpha-tocopherol in colostrum be associated with type of delivery and pre-gestational nutritional status of women.
Curso de Nutrição da Universidade Federal do Rio Grande do Norte-UFRN-Natal, RN, Brasil.
Larissa Queiroz
LQ
de Lira
Penha Patrícia Cabral
PP
Ribeiro
Evellyn Câmara
EC
Grilo
Mayara Santa Rosa
MS
Lima
Roberto
R
Dimenstein
D000293:Adolescent; D000328:Adult; D001942:Breast Feeding; D003126:Colostrum / Q000737:chemistry*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007774:Lactation / Q000097:blood*; D009752:Nutritional Status; D011446:Prospective Studies; D014810:Vitamin E / Q000097:blood; D055815:Young Adult; D024502:alpha-Tocopherol / Q000032:analysis* / Q000097:blood
D014810:Vitamin E; D024502:alpha-Tocopherol