Technical Abstract: Vitamin A deficiency (VAD) is a serious and widespread public health problem in developing countries. We conducted a nationwide food consumption and nutrition survey to inform strategies to address children among others, VAD in Nigeria. As one of the objectives, we assessed the vitamin A status of children < 5 y of age. A total of 6480 households with a mother and child < 5 y of age pair were randomly sampled. Blood samples were collected by venipuncture and processed to obtain serum from which serum retinol was determined by High Performance Liquid Chromatography (HPLC). Results indicate that nationwide 29.5% of children < 5 y of age are vitamin A deficient (serum retinol < 0.70 um/L). The level of VAD among the agro-ecological zones was significantly different from each other at 31.3% in the dry savanna, 24.0% in the moist savanna, and 29.9% in the humid forest (p<0.05). More children with severe deficiency (serum retinol below 0.35 um/L) lived in the humid forest (7.1%) than in the dry savanna (3.1%) and moist savanna (2.4%). The distribution of vitamin A deficient children < 5 y of age was 25.6% in the rural sector, 32.6% in the medium, and 25.9% in the urban sector. These were significantly different from each other at p<0.05. In conclusion, VAD is a severe public health problem in Nigeria. While the proportion of children with low serum vitamin A levels varies agro ecologically and across sectors, it is a significant public health problem in all zones and sectors.