This All Africa article from the Daily Trust breaks down the survey.
This is contained in "The 2008 Situation Assessment and Analysis on Orphans and Vulnerable Children (OVC) in Nigeria" released in Lagos on Tuesday.
The survey, conducted by the Federal Ministry of Women Affairs and Social Development with the support of UNICEF and USAID, spanned from 2006 to 2008.
It revealed that "one tenth of Nigerian children are orphans translating to about 7.3 million orphans in Nigeria".
According to the report, studies by UNICEF and other agencies in Nigeria have projected population of different categories of OVC at different levels as street children, abandoned children, child beggars, street urchins and children orphans by AIDS.
It listed other vulnerable children to include those who have lost one or both parents, children living with terminally or chronically-ill parents, those living with aged grand parents, hawkers and married children.
It said that the OVC were more likely to be recruited to carry out anti-social activities in times of conflict.