ABSTRACT
BACKGROUND: Norwegian health authorities recommend supplementation of essential fatty acids such as cod liver oil to term infants from four weeks of age. The essential fatty acids are seen as contributing to optimal development of the visual acuity and cognitive functions. This study reviews recent research on this issue. MATERIAL AND METHODS: We assessed six randomized controlled trials, published in 1998 and 1999, of which two evaluated visual function and four cognitive development. Outcome were measured by a number of standardized tests. We compared the results from our review with results from a Cochrane review which evaluated six studies published from 1995 to 1997. RESULTS: Only one of the tests used in the visual acuity studies showed significant effect at three out of the four age-related points in time at which the test was administered. Only one of the tests used in the cognitive development studies showed significant effect. INTERPRETATION: The studies reviewed here are in accordance with previous research and do not provide evidence for the claim that supplementation with essential fatty acids as such is significant in order to achieve optimal visual function and cognitive development in healthy term infants.