Inflammation causes a decrease in serum retinol and carotenoids as a consequence of the acute phase response of the organism. Under normal conditions both the acute phase response and the alterations in dynamics of retinol and carotenoids are transient. For both retinoids and carotenoids the adaptive benefit or the principal mechanism causing this decrease are not clear. Because nutritional deficiency results in a similar decrease of these nutritional biomarkers, it is necessary to be able to differentiate between inflammation or nutrition deficiency as the cause. This is of importance with regard to the supplementation of both critically ill patients and populations with a high infection load. The review covers several very recent publications shedding new light on and expanding our knowledge of the interaction between inflammation and the decrease in serum retinol and carotenoids.