Help dealing with nulls.

I am trying to figure out the cleanest way to do something
If I am adding rows to a datatable like below, what is the best way to assign a zero if a value in the row is null?

While dr.Read
                newrow = dt.NewRow
                newrow("Unit") = dr("Unit")
                newrow("One") = dr("One")
                newrow("DT") = dr("DT")
                dt.Rows.Add(newrow)
            End While