Creating VBA If Then Loop through Range of Cells

I have two bits of codes that work seperatley, but I can't figure out how to combine them. I want to go through a column of numbers and test if they are >= 100 and then change the result if true.

I don't know how many rows this column will be so I have used the following line in another part of this Macro.

Range("D1:D" & Final & "").

And I have successfully tested a single cell by directly specifiying it like so:

Sub CellTest()
Dim cell As Integer
cell = Range("D7").Value
If cell >= 100 Then
Range("D7").Value = "NoSplit"
End If
End Sub

Can anybody help me combine these so it iterates through every row and tests the value?