Visual acuity and erythrocyte docosahexaenoic acid status in breast-fed and formula-fed term infants during the first four months of life.

It has been recognized that preterm infants have a more rapid development of visual acuity if fed human milk or a formula enriched with the long-chain polyunsaturated fatty acid (LCPUFA) docosahexaenoic acid (DHA) compared to a standard formula devoid of LCPUFA. Few studies have addressed whether the same is also true in term infants. The aim of the present study was to follow visual acuity and fatty acid composition in red blood cells (RBC) for the first 4 mon of life in 17 breast-fed and 16 formula-fed term infants. The formula used did not contain LCPUFA, but contained 1.7 wt% alpha-linolenic acid, and the linoleic/alpha-linolenic acid ratio was 8.5. The increase in visual acuity measured by Teller acuity cards developed more rapidly in breast-fed infants compared to formula-fed infants (P < 0.001). This was parallelled by a decrease in DHA of RBC in formula-fed infants, and with a significantly lower level at two and four months as compared to breast-fed infants. The content of DHA in milk from the breast-feeding mothers was high compared to other Western countries. The difference in visual acuity between the two feeding groups could be due to differences in DHA status as reflected by the RBC levels, but other explanations are possible. Intervention studies are required to verify if development of visual acuity in term formula-fed infants is dependent on the DHA level of formula.